Cullen/Frost Bankers (CFR) 10-K3 Feb 232022 FY Annual reportFinancial data

Company Profile

Document and Entity Information

Document and Entity Information - USD ($) $ / shares in Units, $ in Billions	12 Months Ended
	Dec. 31, 2022	Jan. 25, 2023	Jun. 30, 2022	Dec. 31, 2021
Entity Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2022
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2022
Document Transition Report	false
Entity File Number	001-13221
Entity Registrant Name	CULLEN/FROST BANKERS, INC.
Entity Incorporation, State or Country Code	TX
Entity Tax Identification Number	74-1751768
Entity Address, Address Line One	111 W. Houston Street,
Entity Address, City or Town	San Antonio,
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	78205
City Area Code	(210)
Local Phone Number	220-4011
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 7.2
Entity Common Stock, Shares Outstanding		64,360,313
Common Stock, Par or Stated Value Per Share	$ 0.01			$ 0.01
Entity Central Index Key	0000039263
Amendment Flag	false
Document Fiscal Period Focus	FY
Auditor Name	Ernst & Young LLP
Auditor Location	San Antonio, Texas
Auditor Firm ID	42
Common Stock [Member] \| NEW YORK STOCK EXCHANGE, INC. [Member]
Entity Information [Line Items]
Title of 12(b) Security	Common Stock, $.01 Par Value
Trading Symbol	CFR
Security Exchange Name	NYSE
Series B Preferred Stock [Member] \| NEW YORK STOCK EXCHANGE, INC. [Member]
Entity Information [Line Items]
Title of 12(b) Security	Depositary Shares, each representing a 1/40th interest in a share of 4.450% Non-Cumulative Perpetual Preferred Stock, Series B
Trading Symbol	CFR.PrB
Security Exchange Name	NYSE

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Assets:
Cash and due from banks	$ 691,553	$ 555,778
Interest-bearing deposits	11,128,902	15,985,244
Federal funds sold	120,527	34,075
Resell agreements	87,150	7,903
Total cash and cash equivalents	12,028,132	16,583,000
Securities held to maturity, net of allowance for credit losses of $158 in 2022 and $158 in 2021	2,639,083	1,749,179
Securities available for sale, at estimated fair value	18,243,605	13,924,628
Trading account securities	28,045	25,162
Loans, net of unearned discounts	17,154,969	16,336,397
Less: Allowance for credit losses on loans	(227,621)	(248,666)
Net loans	16,927,348	16,087,731
Premises and equipment, net	1,102,695	1,050,331
Goodwill	654,952	654,952
Other intangible assets, net	386	866
Cash surrender value of life insurance policies	190,188	190,139
Accrued interest receivable and other assets	1,077,942	612,502
Total assets	52,892,376	50,878,490
Liabilities:
Non-interest-bearing demand deposits	17,598,234	18,423,018
Interest-bearing deposit	26,355,962	24,272,678
Total deposits	43,954,196	42,695,696
Federal funds purchased	51,650	25,925
Repurchase agreements	4,660,641	2,740,799
Junior subordinated deferrable interest debentures, net of unamortized issuance costs	123,069	123,011
Subordinated notes, net of unamortized issuance costs	99,335	99,178
Accrued interest payable and other liabilities	866,257	754,326
Total liabilities	49,755,148	46,438,935
Shareholders’ Equity:
Preferred stock, par value $0.01 per share; 10,000,000 shares authorized; 150,000 Series B shares ($1,000 liquidation preference) issued in 2022 and 2021	145,452	145,452
Common stock, par value $0.01 per share; 210,000,000 shares authorized; 64,354,695 shares issued in 2022 and 64,236,306 shares issued in 2021	643	642
Additional paid-in capital	1,029,756	1,009,921
Retained earnings	3,309,671	2,956,966
Accumulated other comprehensive income, net of tax	(1,348,294)	347,318
Treasury stock, at cost; 250,070 shares in 2021	0	(20,744)
Total shareholders’ equity	3,137,228	4,439,555
Total liabilities and shareholders’ equity	$ 52,892,376	$ 50,878,490

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($)	Dec. 31, 2022	Dec. 31, 2021
Debt Securities, Held-to-maturity, Allowance for Credit Loss	$ (158,000)	$ (158,000)
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Common Stock, Shares Authorized	210,000,000	210,000,000
Common Stock, Shares, Issued	64,354,695	64,236,306
Treasury Stock, Shares		250,070
Series B Preferred Stock [Member]
Preferred Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Preferred Stock, Shares Authorized	10,000,000	10,000,000
Preferred Stock, Shares Issued	150,000	150,000
Preferred Stock, Liquidation Preference, Value	$ 1,000	$ 1,000

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
Consolidated Statements of Income - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Interest income:
Loans, including fees	$ 770,391	$ 674,611	$ 680,064
Securities:
Taxable	249,797	89,550	93,569
Tax-exempt	237,626	226,683	233,614
Interest-bearing deposits	216,367	17,878	12,893
Federal funds sold	948	31	723
Resell agreements	592	16	172
Total interest income	1,475,721	1,008,769	1,021,035
Interest expense:
Deposits	140,476	14,520	32,018
Federal funds purchased	690	32	100
Repurchase agreements	34,443	2,209	4,382
Junior subordinated deferrable interest debentures	4,172	2,484	3,560
Subordinated notes	4,657	4,657	4,656
Federal Home Loan Bank advances	0	0	318
Total interest expense	184,438	23,902	45,034
Net interest income	1,291,283	984,867	976,001
Credit loss expense	3,000	63	241,230
Net interest income after credit loss expense	1,288,283	984,804	734,771
Non-interest income:
Trust and investment management fees	154,679	148,994	129,272
Service charges on deposit accounts	91,891	83,292	80,873
Insurance commissions and fees	53,210	51,548	50,313
Interchange and card transaction fees	18,231	17,461	13,470
Other charges, commissions and fees	41,590	36,836	34,825
Net gain (loss) on securities transactions	0	69	108,989
Other	45,217	48,528	47,712
Total non-interest income	404,818	386,728	465,454
Non-interest expense:
Salaries and wages	492,096	395,497	387,328
Employee benefits	88,608	82,029	75,676
Net occupancy	112,495	107,344	102,938
Technology, furniture and equipment	120,771	112,738	105,232
Deposit insurance	15,603	12,232	10,502
Intangible amortization	480	697	918
Other	194,221	171,457	166,310
Total non-interest expense	1,024,274	881,994	848,904
Income before income taxes	668,827	489,538	351,321
Income taxes	89,677	46,459	20,170
Net income	579,150	443,079	331,151
Preferred stock dividends	6,675	7,157	2,016
Redemption of preferred stock	0	0	5,514
Net income available to common shareholders	$ 572,475	$ 435,922	$ 323,621
Earnings per common share:
Basic (in dollars per share)	$ 8.84	$ 6.79	$ 5.11
Diluted (in dollars per share)	$ 8.81	$ 6.76	$ 5.10

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Net income	$ 579,150	$ 443,079	$ 331,151
Other comprehensive income (loss), before tax:
Change in net unrealized gain/loss on securities available for sale during the period	(2,143,567)	(231,355)	427,331
Change in net unrealized gain on securities transferred to held-to-maturity	(737)	(971)	(1,256)
Reclassification adjustment for net (gains) losses included in net income	0	(69)	(108,989)
Total securities available for sale and transferred securities before tax amount	(2,144,304)	(232,395)	317,086
Defined-benefit post-retirement benefit plans:
Change in the net actuarial gain/loss before tax amount	(5,005)	16,593	(11,518)
Reclassification adjustment for net amortization of actuarial gain/loss included in net income as a component of net periodic cost (benefit) before tax amount	2,964	6,116	5,319
Total defined-benefit post-retirement benefit plans	(2,041)	22,709	(6,199)
Reclassification adjustments for (gains) losses included in net income:
Other comprehensive income (loss), before tax	(2,146,345)	(209,686)	310,887
Deferred tax expense (benefit)	(450,733)	(44,034)	65,287
Other comprehensive income (loss), net of tax	(1,695,612)	(165,652)	245,600
Comprehensive income	$ (1,116,462)	$ 277,427	$ 576,751

Consolidated Statement of Chang

Consolidated Statement of Changes in Shareholders' Equity - USD ($) $ in Thousands	Total	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss), Net of Tax [Member]	Treasury Stock [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of accounting change	$ (29,252)				$ (29,252)
Adjusted beginning balance	3,882,416	$ 144,486	$ 642	$ 983,250	2,638,282	$ 267,370	$ (151,614)
Balance at Dec. 31, 2019	3,911,668	144,486	642	983,250	2,667,534	267,370	(151,614)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	331,151				331,151
Other comprehensive income, net of tax	245,600					245,600
Proceeds from stock option exercises/stock unit conversions (399,810 shares, 987,758 shares, and 408,563 shares during 2022, 2021, and 2020, respectively)	12,557				(27,214)		39,771
Stock-based compensation expense recognized in earnings	13,918			13,918
Stock Redeemed or Called During Period, Value	(150,000)	(144,486)			(5,514)
Stock Issued During Period, Value, New Issues (150,000 shares)	145,452	145,452
Purchase of treasury stock (31,351 shares, 31,317 shares, and 206,951 shares during 2022, 2021, and 2020, respectively)	(15,785)						(15,785)
Treasury Stock issued to the 401(k) stock purchase plan (18,555 shares in 2021 and 140,264 shares in 2020)	10,307				(3,382)		13,689
Cash dividends paid on preferred stock (approximately $44.50 per share which is equivalent to approximately $1.11 per depositary share in 2022 and approximately $47.71 per share which is equivalent to approximately $1.19 per share in 2021 and $0.34 per share in 2020)	(2,016)				(2,016)
Cash dividends – common stock ($3.24 per share, $2.94 per share, and $2.85 per share in 2022, 2021, and 2020, respectively)	(180,584)				(180,584)
Balance at Dec. 31, 2020	4,293,016	145,452	642	997,168	2,750,723	512,970	(113,939)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	443,079				443,079
Other comprehensive income, net of tax	(165,652)					(165,652)
Proceeds from stock option exercises/stock unit conversions (399,810 shares, 987,758 shares, and 408,563 shares during 2022, 2021, and 2020, respectively)	54,417				(40,836)		95,253
Stock-based compensation expense recognized in earnings	12,753			12,753
Purchase of treasury stock (31,351 shares, 31,317 shares, and 206,951 shares during 2022, 2021, and 2020, respectively)	(3,864)						(3,864)
Treasury Stock issued to the 401(k) stock purchase plan (18,555 shares in 2021 and 140,264 shares in 2020)	1,749				(57)		1,806
Cash dividends paid on preferred stock (approximately $44.50 per share which is equivalent to approximately $1.11 per depositary share in 2022 and approximately $47.71 per share which is equivalent to approximately $1.19 per share in 2021 and $0.34 per share in 2020)	(7,157)				(7,157)
Cash dividends – common stock ($3.24 per share, $2.94 per share, and $2.85 per share in 2022, 2021, and 2020, respectively)	(188,786)				(188,786)
Balance at Dec. 31, 2021	4,439,555	145,452	642	1,009,921	2,956,966	347,318	(20,744)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	579,150				579,150
Other comprehensive income, net of tax	(1,695,612)					(1,695,612)
Proceeds from stock option exercises/stock unit conversions (399,810 shares, 987,758 shares, and 408,563 shares during 2022, 2021, and 2020, respectively)	16,659		1	1,513	(9,990)		25,135
Stock-based compensation expense recognized in earnings	18,322			18,322
Purchase of treasury stock (31,351 shares, 31,317 shares, and 206,951 shares during 2022, 2021, and 2020, respectively)	(4,391)						(4,391)
Treasury Stock issued to the 401(k) stock purchase plan (18,555 shares in 2021 and 140,264 shares in 2020)	0
Cash dividends paid on preferred stock (approximately $44.50 per share which is equivalent to approximately $1.11 per depositary share in 2022 and approximately $47.71 per share which is equivalent to approximately $1.19 per share in 2021 and $0.34 per share in 2020)	(6,675)				(6,675)
Cash dividends – common stock ($3.24 per share, $2.94 per share, and $2.85 per share in 2022, 2021, and 2020, respectively)	(209,780)				(209,780)
Balance at Dec. 31, 2022	$ 3,137,228	$ 145,452	$ 643	$ 1,029,756	$ 3,309,671	$ (1,348,294)	$ 0

Consolidated Statement of Cha_2

Consolidated Statement of Changes in Shareholders' Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Stock option exercises/deferred stock unit conversions, shares	399,810	987,758	408,563
Stock Redeemed or Called During Period, Shares			6,000,000
Stock Issued During Period, Shares, New Issues			150,000
Treasury Stock, Shares, Acquired	31,351	31,317	206,951
Stock Issued During Period, Shares, Treasury Stock Reissued		18,555	140,264
Preferred Stock, Dividends Per Share, Declared	$ 44.50	$ 47.71	$ 0.34
Preferred stock, Dividends equivalent per depositary share, Declared	1.11	1.19
Common Stock, Dividends, Per Share, Cash Paid	$ 3.24	$ 2.94	$ 2.85

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Operating Activities:
Net income	$ 579,150	$ 443,079	$ 331,151
Adjustments to reconcile net income to net cash from operating activities:
Credit loss expense	3,000	63	241,230
Deferred tax expense (benefit)	(4,918)	7,784	(15,832)
Accretion of loan discounts	(12,921)	(12,890)	(15,692)
Securities premium amortization (discount accretion), net	97,400	119,242	123,785
Net (gain) loss on securities transactions	0	(69)	(108,989)
Depreciation and amortization	71,344	69,289	64,370
Net (gain) loss on sale/exchange/write-down of assets/foreclosed assets	109	(11,578)	524
Stock-based compensation	18,322	12,753	13,918
Net tax benefit from stock-based compensation	4,602	7,877	852
Earnings on life insurance policies	(2,096)	(2,462)	(3,731)
Net change in:
Trading account securities	(716)	(560)	(158)
Lease right-of-use assets	24,409	23,504	23,933
Accrued interest receivable and other assets	(116,243)	(46,560)	(158,264)
Accrued interest payable and other liabilities	61,140	38,821	27,146
Net cash provided by (used in) operating activities	722,582	648,293	524,243
Investing Activities:
Securities held to maturity: Purchases	(1,424,105)	0	(1,500)
Securities held to maturity: Maturities, calls and principal repayments	561,388	177,593	63,577
Securities available for sale:
Purchases	(22,178,248)	(24,217,841)	(20,841,622)
Sales	0	1,999,891	1,162,352
Maturities, calls and principal repayments	15,683,097	18,425,108	20,893,464
Proceeds from sale of loans	2,365	0	37,535
Net change in loans	(824,021)	1,145,924	(2,856,395)
Benefits received on life insurance policies	2,047	2,307	903
Proceeds from sales of premises and equipment	63	7,044	5,988
Purchases of premises and equipment	(102,501)	(65,850)	(95,422)
Proceeds from sales of repossessed properties	2,585	809	73
Net cash provided by (used in) investing activities	(8,277,330)	(2,525,015)	(1,631,047)
Financing Activities:
Net change in deposits	1,258,500	7,679,935	7,376,197
Net change in short-term borrowings	1,945,567	649,727	421,655
Proceeds from Federal Home Loan Bank advances	0	0	1,250,000
Principal payments on Federal Home Loan Bank advances	0	0	(1,250,000)
Principal payments on long-term borrowings	0	(13,403)	0
Redemption of Series A preferred stock	0	0	(150,000)
Proceeds from issuance of Series B preferred stock	0	0	145,452
Proceeds from stock option exercises	16,659	54,417	12,557
Purchase of treasury stock	(4,391)	(3,864)	(15,785)
Cash dividends paid on preferred stock	(6,675)	(7,157)	(2,016)
Cash dividends paid on common stock	(209,780)	(188,786)	(180,584)
Net cash provided by (used in) financing activities	2,999,880	8,170,869	7,607,476
Net change in cash and cash equivalents	(4,554,868)	6,294,147	6,500,672
Cash and cash equivalents at beginning of year	16,583,000	10,288,853	3,788,181
Cash and cash equivalents at end of year	$ 12,028,132	$ 16,583,000	$ 10,288,853

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
Summary of Significant Accounting Policies	Dec. 31, 2022
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Nature of Operations . Cullen/Frost Bankers, Inc. (“Cullen/Frost”) is a financial holding company and a bank holding company headquartered in San Antonio, Texas that provides, through its subsidiaries, a broad array of products and services throughout numerous Texas markets. The terms “Cullen/Frost,” “the Corporation,” “we,” “us” and “our” mean Cullen/Frost Bankers, Inc. and its subsidiaries, when appropriate. In addition to general commercial and consumer banking, other products and services offered include trust and investment management, insurance, brokerage, mutual funds, leasing, treasury management, capital markets advisory and item processing. Basis of Presentation. The consolidated financial statements include the accounts of Cullen/Frost and all other entities in which Cullen/Frost has a controlling financial interest. All significant intercompany balances and transactions have been eliminated in consolidation. The accounting and financial reporting policies we follow conform, in all material respects, to accounting principles generally accepted in the United States and to general practices within the financial services industry. We determine whether we have a controlling financial interest in an entity by first evaluating whether the entity is a voting interest entity or a variable interest entity (“VIE”) under accounting principles generally accepted in the United States. Voting interest entities are entities in which the total equity investment at risk is sufficient to enable the entity to finance itself independently and provides the equity holders with the obligation to absorb losses, the right to receive residual returns and the right to make decisions about the entity’s activities. We consolidate voting interest entities in which we have all, or at least a majority of, the voting interest. As defined in applicable accounting standards, VIEs are entities that lack one or more of the characteristics of a voting interest entity. A controlling financial interest in a VIE is present when an enterprise has both the power to direct the activities of the VIE that most significantly impact the VIE’s economic performance and an obligation to absorb losses or the right to receive benefits that could potentially be significant to the VIE. The enterprise with a controlling financial interest, known as the primary beneficiary, consolidates the VIE. Our wholly-owned subsidiary, Cullen/Frost Capital Trust II, is a VIE for which we are not the primary beneficiary and, as such, its accounts are not included in our consolidated financial statements. Acquisitions are accounted for using the purchase method with the operating results of the acquired companies included with our results of operations since their respective dates of acquisition. We have evaluated subsequent events for potential recognition and/or disclosure through the date these consolidated financial statements were issued. Use of Estimates . The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements. Actual results could differ from those estimates. The allowance for credit losses on loans and off-balance-sheet credit exposures, the fair values of financial instruments and the status of contingencies are particularly subject to change. Concentrations and Restrictions on Cash and Cash Equivalents . We maintain deposits with other financial institutions in amounts that exceed federal deposit insurance coverage. Furthermore, federal funds sold are essentially uncollateralized loans to other financial institutions. Management regularly evaluates the credit risk associated with the counterparties to these transactions and believes that we are not exposed to any significant credit risks on cash and cash equivalents. As of December 31, 2022 and 2021, we had $3.2 million and $110.3 million in cash collateral on deposit with other financial institution counterparties to interest rate swap transactions. Cash Flow Reporting . Cash and cash equivalents include cash, deposits with other financial institutions that have an initial maturity of less than 90 days when acquired by us, federal funds sold and resell agreements. Net cash flows are reported for loans, deposit transactions and short-term borrowings. Additional cash flow information was as follows: Year Ended December 31, 2022 2021 2020 Cash paid for interest $ 169,020 $ 29,003 $ 49,300 Cash paid for income tax 100,000 39,852 44,140 Significant non-cash transactions: Exchange of real estate — 11,036 — Unsettled securities transactions 94,884 27,032 57,783 Loans foreclosed and transferred to other real estate owned and foreclosed assets 239 3,464 140 Right-of-use lease assets obtained in exchange for lessee operating lease liabilities 31,787 12,854 18,284 Treasury stock issued to 401(k) stock purchase plan — 1,749 10,307 Repurchase/Resell Agreements. We purchase certain securities under agreements to resell. The amounts advanced under these agreements represent short-term loans and are reflected as assets in the accompanying consolidated balance sheets. The securities underlying these agreements are book-entry securities. We also sell certain securities under agreements to repurchase. The agreements are treated as collateralized financing transactions and the obligations to repurchase securities sold are reflected as a liability in the accompanying consolidated balance sheets. The dollar amount of the securities underlying the agreements remains in the asset accounts. Securities. Securities are classified as held to maturity and carried at amortized cost when management has the positive intent and ability to hold them until maturity. Securities to be held for indefinite periods of time are classified as available for sale and carried at fair value, with the unrealized holding gains and losses (those for which no allowance for credit losses are recorded) reported as a component of other comprehensive income, net of tax. Securities held for resale in anticipation of short-term market movements are classified as trading and are carried at fair value, with changes in unrealized holding gains and losses included in income. Management determines the appropriate classification of securities at the time of purchase. Securities with limited marketability, such as stock in the Federal Reserve Bank and the Federal Home Loan Bank, are carried at cost. Interest income on securities includes amortization of purchase premiums and discounts. Premiums and discounts on securities are generally amortized using the interest method with a constant effective yield without anticipating prepayments, except for mortgage-backed securities where prepayments are anticipated. Premiums on callable securities are amortized to their earliest call date. A security is placed on non-accrual status if (i) principal or interest has been in default for a period of 90 days or more or (ii) full payment of principal and interest is not expected. Interest accrued but not received for a security placed on non-accrual status is reversed against interest income. Gains and losses on sales are recorded on the trade date and are derived from the amortized cost of the security sold. Loans . Loans are reported at the principal balance outstanding net of unearned discounts. Interest income on loans is reported on the level-yield method and includes amortization of deferred loan fees and costs over the terms of the individual loans to which they relate, or, in certain cases, over the average expected term for loans where deferred fees and costs are accounted for on a pooled basis. Net loan commitment fees or costs for commitment periods greater than one year are deferred and amortized into fee income or other expense on a straight-line basis over the commitment period. Income on direct financing leases is recognized on a basis that achieves a constant periodic rate of return on the outstanding investment. Further information regarding our accounting policies related to past due loans, non-accrual loans, impaired loans and troubled-debt restructurings is presented in Note 3 - Loans. Allowance for Credit Losses. As further discussed below, we adopted Accounting Standards Update (“ASU”) 2016-13, “Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments,” on January 1, 2020. Accounting Standards Codification (“ASC”) Topic 326 (“ASC 326”) replaced the previous “incurred loss” model for measuring credit losses, which encompassed allowances for current known and inherent losses within the portfolio, with an “expected loss” model, which encompasses allowances for losses expected to be incurred over the life of the portfolio. The new current expected credit loss (“CECL”) model requires the measurement of all expected credit losses for financial assets measured at amortized cost and certain off-balance- sheet credit exposures based on historical experience, current conditions, and reasonable and supportable forecasts. In connection with the adoption of ASC 326, we revised certain accounting policies and implemented certain accounting policy elections. The revised accounting policies are described below. Allowance For Credit Losses - Held-to-Maturity Securities: The allowance for credit losses on held-to-maturity securities is a contra-asset valuation account, calculated in accordance with ASC 326, that is deducted from the amortized cost basis of held-to-maturity securities to present management's best estimate of the net amount expected to be collected. Held-to-maturity securities are charged-off against the allowance when deemed uncollectible by management. Adjustments to the allowance are reported in our income statement as a component of credit loss expense. Management measures expected credit losses on held-to-maturity securities on a collective basis by major security type with each type sharing similar risk characteristics and considers historical credit loss information that is adjusted for current conditions and reasonable and supportable forecasts. Management has made the accounting policy election to exclude accrued interest receivable on held-to-maturity securities from the estimate of credit losses. Further information regarding our policies and methodology used to estimate the allowance for credit losses on held-to-maturity securities is presented in Note 2 - Securities. Allowance For Credit Losses - Available-for-Sale Securities: For available-for-sale securities in an unrealized loss position, we first assess whether (i) we intend to sell or (ii) it is more likely than not that we will be required to sell the security before recovery of its amortized cost basis. If either case is affirmative, any previously recognized allowances are charged-off and the security's amortized cost is written down to fair value through income. If neither case is affirmative, the security is evaluated to determine whether the decline in fair value has resulted from credit losses or other factors. In making this assessment, management considers the extent to which fair value is less than amortized cost, any changes to the rating of the security by a rating agency and any adverse conditions specifically related to the security, among other factors. If this assessment indicates that a credit loss exists, the present value of cash flows expected to be collected from the security are compared to the amortized cost basis of the security. If the present value of cash flows expected to be collected is less than the amortized cost basis, a credit loss exists and an allowance for credit losses is recorded for the credit loss, limited by the amount that the fair value is less than the amortized cost basis. Any impairment that has not been recorded through an allowance for credit losses is recognized in other comprehensive income. Adjustments to the allowance are reported in our income statement as a component of credit loss expense. Management has made the accounting policy election to exclude accrued interest receivable on available-for-sale securities from the estimate of credit losses. Available-for-sale securities are charged-off against the allowance or, in the absence of any allowance, written down through income when deemed uncollectible by management or when either of the aforementioned criteria regarding intent or requirement to sell is met. Prior to the adoption of ASU 2016-13, declines in the fair value of held-to-maturity and available-for-sale securities below their cost that were deemed to be other than temporary were reflected in earnings as realized losses. In estimating other-than-temporary impairment losses prior to January 1, 2020, management considered, among other things, (i) the length of time and the extent to which the fair value had been less than cost, (ii) the financial condition and near-term prospects of the issuer and (iii) the intent and our ability to retain our investment in the issuer for a period of time sufficient to allow for any anticipated recovery in fair value. Allowance for Credit Losses - Loans: The allowance for credit losses on loans is a contra-asset valuation account, calculated in accordance with ASC 326, that is deducted from the amortized cost basis of loans to present management's best estimate of the net amount expected to be collected. Loans are charged-off against the allowance when deemed uncollectible by management. Expected recoveries do not exceed the aggregate of amounts previously charged-off and expected to be charged-off. Adjustments to the allowance are reported in our income statement as a component of credit loss expense. Management has made the accounting policy election to exclude accrued interest receivable on loans from the estimate of credit losses. Further information regarding our policies and methodology used to estimate the allowance for credit losses on loans is presented in Note 3 - Loans. Allowance For Credit Losses - Off-Balance-Sheet Credit Exposures: The allowance for credit losses on off-balance-sheet credit exposures is a liability account, calculated in accordance with ASC 326, representing expected credit losses over the contractual period for which we are exposed to credit risk resulting from a contractual obligation to extend credit. No allowance is recognized if we have the unconditional right to cancel the obligation. The allowance is reported as a component of accrued interest payable and other liabilities in our consolidated balance sheets. Adjustments to the allowance are reported in our income statement as a component of credit loss expense. Further information regarding our policies and methodology used to estimate the allowance for credit losses on off-balance-sheet credit exposures is presented in Note 8 - Off-Balance-Sheet Arrangements, Commitments, Guarantees and Contingencies. Premises and Equipment. Land is carried at cost. Building and improvements, and furniture and equipment are carried at cost, less accumulated depreciation, computed principally by the straight-line method based on the estimated useful lives of the related property. Leasehold improvements are generally depreciated over the lesser of the term of the respective leases or the estimated useful lives of the improvements. We lease certain office facilities and office equipment under operating leases. We also own certain office facilities which we lease to outside parties under operating lessor leases; however, such leases are not significant. For operating leases other than those considered to be short-term, we recognize lease right-of-use assets and related lease liabilities. Such amounts are reported as components of premises and equipment and accrued interest payable and other liabilities, respectively, on our accompanying consolidated balance sheet. We do not recognize short-term operating leases on our balance sheet. A short-term operating lease has an original term of 12 months or less and does not have a purchase option that is likely to be exercised. In recognizing lease right-of-use assets and related lease liabilities, we account for lease and non-lease components (such as taxes, insurance, and common area maintenance costs) separately as such amounts are generally readily determinable under our lease contracts. Lease payments over the expected term are discounted using our incremental borrowing rate referenced to the Federal Home Loan Bank Secure Connect advance rates for borrowings of similar term. We also consider renewal and termination options in the determination of the term of the lease. If it is reasonably certain that a renewal or termination option will be exercised, the effects of such options are included in the determination of the expected lease term. Generally, we cannot be reasonably certain about whether or not we will renew a lease until such time the lease is within the last two years of the existing lease term. However, renewal options related to our regional headquarters facilities or operations centers are evaluated on a case-by-case basis, typically in advance of such time frame. When we are reasonably certain that a renewal option will be exercised, we measure/remeasure the right-of-use asset and related lease liability using the lease payments specified for the renewal period or, if such amounts are unspecified, we generally assume an increase (evaluated on a case-by-case basis in light of prevailing market conditions) in the lease payment over the final period of the existing lease term. Foreclosed Assets . Assets acquired through or instead of loan foreclosure are held for sale and are initially recorded at fair value less estimated selling costs when acquired, establishing a new cost basis. Write-downs occurring at acquisition are charged against the allowance for credit losses on loans. Foreclosed assets are included in other assets in the accompanying consolidated balance sheets and totaled $964 thousand and $3.4 million at December 31, 2022 and 2021. Regulatory guidelines require us to reevaluate the fair value of foreclosed assets on at least an annual basis. Our policy is to comply with the regulatory guidelines. If the fair value of the asset declines, a write-down is recorded through other non-interest expense along with other expenses related to maintaining the properties. The valuation of foreclosed assets is subjective in nature and may be adjusted in the future because of changes in economic conditions. There were no write-downs of foreclosed assets in 2022, while write-downs of foreclosed assets totaled $14 thousand in 2021 and $231 thousand in 2020. There were no significant concentrations of any properties, to which the aforementioned write-downs relate, in any single geographic region. Goodwill. Goodwill represents the excess of the cost of businesses acquired over the fair value of the net assets acquired. Goodwill is assigned to reporting units and tested for impairment at least annually on October 1st, or on an interim basis if an event occurs or circumstances change that would more likely than not reduce the fair value of the reporting unit below its carrying value. See Note 5 - Goodwill and Other Intangible Assets. Intangibles and Other Long-Lived Assets . Intangible assets are acquired assets that lack physical substance but can be distinguished from goodwill because of contractual or other legal rights or because the asset is capable of being sold or exchanged either on its own or in combination with a related contract, asset, or liability. Our intangible assets relate to core deposits, non-compete agreements and customer relationships. Intangible assets with definite useful lives are amortized on an accelerated basis over their estimated life. Intangible assets with indefinite useful lives are not amortized until their lives are determined to be definite. Intangible assets, premises and equipment and other long-lived assets are tested for impairment whenever events or changes in circumstances indicate the carrying amount of the assets may not be recoverable from future undiscounted cash flows. If impaired, the assets are recorded at fair value. See Note 5 - Goodwill and Other Intangible Assets. Revenue Recognition . In general, for revenue not associated with financial instruments, guarantees and lease contracts, we apply the following steps when recognizing revenue from contracts with customers: (i) identify the contract, (ii) identify the performance obligations, (iii) determine the transaction price, (iv) allocate the transaction price to the performance obligations and (v) recognize revenue when a performance obligation is satisfied. Our contracts with customers are generally short term in nature, typically due within one year or less or cancellable by us or our customer upon a short notice period. Performance obligations for our customer contracts are generally satisfied at a single point in time, typically when the transaction is complete, or over time. For performance obligations satisfied over time, we primarily use the output method, directly measuring the value of the products/services transferred to the customer, to determine when performance obligations have been satisfied. We typically receive payment from customers and recognize revenue concurrent with the satisfaction of our performance obligations. In most cases, this occurs within a single financial reporting period. For payments received in advance of the satisfaction of performance obligations, revenue recognition is deferred until such time as the performance obligations have been satisfied. In cases where we have not received payment despite satisfaction of our performance obligations, we accrue an estimate of the amount due in the period our performance obligations have been satisfied. For contracts with variable components, only amounts for which collection is probable are accrued. We generally act in a principal capacity, on our own behalf, in most of our contracts with customers. In such transactions, we recognize revenue and the related costs to provide our services on a gross basis in our financial statements. In some cases, we act in an agent capacity, deriving revenue through assisting other entities in transactions with our customers. In such transactions, we recognize revenue and the related costs to provide our services on a net basis in our financial statements. These transactions recognized on a net basis primarily relate to insurance and brokerage commissions and fees derived from our customers' use of various interchange and ATM/debit card networks. Share-Based Payments . Compensation expense for stock options, non-vested stock awards/stock units and deferred stock units is based on the fair value of the award on the measurement date, which, for us, is the date of the grant and is recognized ratably over the service period of the award. Compensation expense for performance stock units is based on the fair value of the award on the measurement date, which, for us, is the date of the grant and is recognized over the service period of the award based upon the probable number of units expected to vest. The fair value of stock options is estimated using a binomial lattice-based valuation model. The fair value of non-vested stock awards/stock units and deferred stock units is generally the market price of our stock on the date of grant. The fair value of performance stock units is generally the market price of our stock on the date of grant discounted by the present value of the dividends expected to be paid on our common stock during the service period of the award because dividend equivalent payments on performance stock units are deferred until such time that the units vest and shares are issued. The impact of forfeitures of share-based payment awards on compensation expense is recognized as forfeitures occur. Advertising Costs. Advertising costs are expensed as incurred. Income Taxes . Income tax expense is the total of the current year income tax due or refundable and the change in deferred tax assets and liabilities (excluding deferred tax assets and liabilities related to business combinations or components of other comprehensive income). Deferred tax assets and liabilities are the expected future tax amounts for the temporary differences between carrying amounts and tax bases of assets and liabilities, computed using enacted tax rates. A valuation allowance, if needed, reduces deferred tax assets to the expected amount most likely to be realized. Realization of deferred tax assets is dependent upon the generation of a sufficient level of future taxable income. Although realization is not assured, management believes it is more likely than not that all of the deferred tax assets will be realized. Interest and/or penalties related to income taxes are reported as a component of income tax expense. The income tax effects related to settlements of share-based payment awards are reported in earnings as an increase (or decrease) to income tax expense. See Note 13 - Income Taxes. We file a consolidated income tax return with our subsidiaries. Federal income tax expense or benefit has been allocated to subsidiaries on a separate return basis. Basic and Diluted Earnings Per Common Share. Earnings per common share is computed using the two-class method prescribed under ASC Topic 260, “Earnings Per Share.” ASC 260 provides that unvested share-based payment awards that contain nonforfeitable rights to dividends or dividend equivalents (whether paid or unpaid) are participating securities and shall be included in the computation of earnings per share pursuant to the two-class method. We have determined that our outstanding non-vested stock awards/stock units and deferred stock units are participating securities. Under the two-class method, basic earnings per common share is computed by dividing net earnings allocated to common stock by the weighted-average number of common shares outstanding during the applicable period, excluding outstanding participating securities. Diluted earnings per common share is computed using the weighted-average number of shares determined for the basic earnings per common share computation plus the dilutive effect of stock compensation using the treasury stock method. A reconciliation of the weighted-average shares used in calculating basic earnings per common share and the weighted average common shares used in calculating diluted earnings per common share for the reported periods is provided in Note 10 - Earnings Per Common Share. Comprehensive Income. Comprehensive income includes all changes in shareholders’ equity during a period, except those resulting from transactions with shareholders. Besides net income, other components of our comprehensive income include the after tax effect of changes in the net unrealized gain/loss on securities available for sale, changes in the net unrealized gain on securities transferred to held to maturity and changes in the net actuarial gain/loss on defined benefit post-retirement benefit plans. See Note 14 - Other Comprehensive Income (Loss). Derivative Financial Instruments . Our hedging policies permit the use of various derivative financial instruments to manage interest rate risk or to hedge specified assets and liabilities. All derivatives are recorded at fair value on our balance sheet. Derivatives executed with the same counterparty are generally subject to master netting arrangements, however, fair value amounts recognized for derivatives and fair value amounts recognized for the right/obligation to reclaim/return cash collateral are not offset for financial reporting purposes. We may be required to recognize certain contracts and commitments as derivatives when the characteristics of those contracts and commitments meet the definition of a derivative. To qualify for hedge accounting, derivatives must be highly effective at reducing the risk associated with the exposure being hedged and must be designated as a hedge at the inception of the derivative contract. We consider a hedge to be highly effective if the change in fair value of the derivative hedging instrument is within 80% to 125% of the opposite change in the fair value of the hedged item attributable to the hedged risk. If derivative instruments are designated as hedges of fair values, and such hedges are highly effective, both the change in the fair value of the hedge and the hedged item are included in current earnings. Fair value adjustments related to cash flow hedges are recorded in other comprehensive income and are reclassified to earnings when the hedged transaction is reflected in earnings. Ineffective portions of hedges are reflected in earnings as they occur. Actual cash receipts and/or payments and related accruals on derivatives related to hedges are recorded as adjustments to the interest income or interest expense associated with the hedged item. During the life of the hedge, we formally assess whether derivatives designated as hedging instruments continue to be highly effective in offsetting changes in the fair value or cash flows of hedged items. If it is determined that a hedge has ceased to be highly effective, we will discontinue hedge accounting prospectively. At such time, previous adjustments to the carrying value of the hedged item are reversed into current earnings and the derivative instrument is reclassified to a trading position recorded at fair value. Fair Value Measurements . In general, fair values of financial instruments are based upon quoted market prices, where available. If such quoted market prices are not available, fair value is based upon internally developed models that primarily use, as inputs, observable market-based parameters. Valuation adjustments may be made to ensure that financial instruments are recorded at fair value. These adjustments may include amounts to reflect counterparty credit quality and our creditworthiness, among other things, as well as unobservable parameters. Any such valuation adjustments are applied consistently over time. See Note 17 - Fair Value Measurements. Transfers of Financial Assets . Transfers of financial assets are accounted for as sales when control over the assets has been surrendered. Control over transferred assets is deemed to be surrendered when (i) the assets have been isolated from us, (ii) the transferee obtains the right (free of conditions that constrain it from taking advantage of that right) to pledge or exchange the transferred assets, and (iii) we do not maintain effective control over the transferred assets through an agreement to repurchase them before their maturity. Loss Contingencies . Loss contingencies, including claims and legal actions arising in the ordinary course of business are recorded as liabilities when the likelihood of loss is probable and an amount or range of loss can be reasonably estimated. Trust Assets. Assets of our trust department, other than cash on deposit at Frost Bank, are not included in the accompanying financial statements because they are not our assets. Accounting Changes, Reclassifications and Restatements. Certain items in prior financial statements have been reclassified to conform to the current presentation. As discussed above, on January 1, 2020 we adopted the provisions of ASC 326 using the modified retrospective method for all financial assets measured at amortized cost and off-balance-sheet credit exposures. Upon adoption, we recognized an after-tax cumulative effect reduction to retained earnings totaling $29.3 million, as detailed in the table below. The following table details the impact of the adoption of ASC 326 on the allowance for credit losses as of January 1, 2020. January 1, 2020 Pre-Adoption Allowance Impact of Adoption Post-Adoption Allowance Cumulative Effect on Retained Earnings Securities held to maturity: U.S. Treasury $ — $ — $ — $ — Residential mortgage-backed securities — — — — States and political subdivisions — 215 215 (170) Other — — — — Total $ — $ 215 $ 215 $ (170) Loans: Commercial and industrial $ 51,593 $ 21,263 $ 72,856 $ (16,798) Energy 37,382 (10,453) 26,929 8,258 Commercial real estate 31,037 (13,519) 17,518 10,680 Consumer real estate 4,113 2,392 6,505 (1,890) Consumer and other 8,042 (2,248) 5,794 1,776 Total $ 132,167 $ (2,565) $ 129,602 $ 2,026 Off-balance-sheet credit exposures $ 500 $ 39,377 $ 39,877 $ (31,108)

Securities

Securities	12 Months Ended
Securities	Dec. 31, 2022
Investments, Debt and Equity Securities [Abstract]
Securities	Securities Securities - Held to Maturity. A summary of the amortized cost, fair value and allowance for credit losses related to securities held to maturity as of December 31, 2022 and 2021 is presented below. Amortized Gross Gross Estimated Allowance Net December 31, 2022 Residential mortgage-backed securities $ 526,122 $ — $ 65,322 $ 460,800 $ — $ 526,122 States and political subdivisions 2,111,619 13,048 119,033 2,005,634 (158) 2,111,461 Other 1,500 — 69 1,431 — 1,500 Total $ 2,639,241 $ 13,048 $ 184,424 $ 2,467,865 $ (158) $ 2,639,083 December 31, 2021 Residential mortgage-backed securities $ 527,264 $ 18,766 $ — $ 546,030 $ — $ 527,264 States and political subdivisions 1,220,573 41,141 101 1,261,613 (158) 1,220,415 Other 1,500 — — 1,500 — 1,500 Total $ 1,749,337 $ 59,907 $ 101 $ 1,809,143 $ (158) $ 1,749,179 All mortgage-backed securities included in the above table were issued by U.S. government agencies and corporations. The carrying value of held-to-maturity securities pledged to secure public funds, trust deposits, repurchase agreements and for other purposes, as required or permitted by law was $256.3 million and $642.3 million at December 31, 2022 and 2021, respectively. Accrued interest receivable on held-to-maturity securities totaled $30.2 million and $18.4 million at December 31, 2022 and 2021, respectively and is included in accrued interest receivable and other assets in the accompanying consolidated balance sheets. From time to time, we have reclassified certain securities from available for sale to held to maturity. The net unamortized, unrealized gain remaining on securities transferred in years prior to 2020 included in accumulated other comprehensive income in the accompanying balance sheet totaled $1.8 million ($1.4 million, net of tax) at December 31, 2022 and $2.5 million ($2.0 million, net of tax) at December 31, 2021. This amount will be amortized out of accumulated other comprehensive income over the remaining life of the underlying securities as an adjustment of the yield on those securities. The allowance for credit losses on held-to-maturity securities is a contra-asset valuation account that is deducted from the amortized cost basis of held-to-maturity securities to present the net amount expected to be collected. Management measures expected credit losses on held-to-maturity securities on a collective basis by major security type with each type sharing similar risk characteristics, and considers historical credit loss information that is adjusted for current conditions and reasonable and supportable forecasts. With regard to U.S. Treasury and residential mortgage-backed securities issued by the U.S. government, or agencies thereof, it is expected that the securities will not be settled at prices less than the amortized cost bases of the securities as such securities are backed by the full faith and credit of and/or guaranteed by the U.S. government. Accordingly, no allowance for credit losses has been recorded for these securities. With regard to securities issued by States and political subdivisions and other held-to-maturity securities, management considers (i) issuer bond ratings, (ii) historical loss rates for given bond ratings, (iii) whether issuers continue to make timely principal and interest payments under the contractual terms of the securities, (iv) internal forecasts and (v) whether or not such securities are guaranteed by the Texas Permanent School Fund (“PSF”) or pre-refunded by the issuers. The following table summarizes Moody's and/or Standard & Poor's bond ratings for our portfolio of held-to-maturity securities issued by States and political subdivisions and other securities as of December 31, 2022: States and Political Subdivisions Not Guaranteed or Pre-Refunded Guaranteed by the Texas PSF Pre-Refunded Total Other Aaa/AAA $ 273,201 $ 1,422,442 $ 121,961 $ 1,817,604 $ — Aa/AA 294,015 — — 294,015 — Not rated — — — — 1,500 Total $ 567,216 $ 1,422,442 $ 121,961 $ 2,111,619 $ 1,500 Historical loss rates associated with securities having similar grades as those in our portfolio have generally not been significant. Furthermore, as of December 31, 2022, there were no past due principal or interest payments associated with these securities. The PSF is a sovereign wealth fund which serves to provide revenues for funding of public primary and secondary education in the State of Texas. Based upon (i) the PSF's AAA insurer financial strength rating, (ii) the PSF's substantial capitalization and excess guarantee capacity and (iii) a zero historical loss rate, no allowance for credit losses has been recorded for securities guaranteed by the PSF as there is no current expectation of credit losses related to these securities. Pre-refunded securities have been defeased by the issuer and are fully secured by cash and/or U.S. Treasury securities held in escrow for payment to holders when the underlying call dates of the securities are reached. Accordingly, no allowance for credit losses has been recorded for securities that have been defeased as there is no current expectation of credit losses related to these securities. The following table details activity in the allowance for credit losses on held-to-maturity securities. 2022 2021 2020 Beginning balance $ 158 $ 160 $ — Impact of adopting ASC 326 — — 215 Credit loss expense (benefit) — (2) (55) Ending balance $ 158 $ 158 $ 160 Securities - Available for Sale. A summary of the amortized cost, fair value and allowance for credit losses related to securities available for sale as of December 31, 2022 and 2021 is presented below. Amortized Gross Gross Allowance Estimated December 31, 2022 U.S. Treasury $ 5,450,546 $ — $ 398,959 $ — $ 5,051,587 Residential mortgage-backed securities 7,316,824 8,050 948,638 — 6,376,236 States and political subdivisions 7,098,635 9,108 334,388 — 6,773,355 Other 42,427 — — — 42,427 Total $ 19,908,432 $ 17,158 $ 1,681,985 $ — $ 18,243,605 December 31, 2021 U.S. Treasury $ 2,165,702 $ 23,333 $ 9,602 $ — $ 2,179,433 Residential mortgage-backed securities 4,059,692 31,662 25,089 — 4,066,265 States and political subdivisions 7,178,135 463,810 5,374 — 7,636,571 Other 42,359 — — — 42,359 Total $ 13,445,888 $ 518,805 $ 40,065 $ — $ 13,924,628 All mortgage-backed securities included in the above table were issued by U.S. government agencies and corporations. At December 31, 2022 all of the securities in our available for sale municipal bond portfolio were issued by the State of Texas or political subdivisions or agencies within the State of Texas, of which approximately 75.9% are either guaranteed by the PSF or have been pre-refunded. Securities with limited marketability, such as stock in the Federal Reserve Bank and the Federal Home Loan Bank, are carried at cost and are reported as other available for sale securities in the table above. The carrying value of available-for-sale securities pledged to secure public funds, trust deposits, repurchase agreements and for other purposes, as required or permitted by law was $8.0 billion and $5.8 billion at December 31, 2022 and 2021, respectively. Accrued interest receivable on available-for-sale securities totaled $140.6 million and $120.5 million at December 31, 2022 and 2021, respectively, and is included in accrued interest receivable and other assets in the accompanying consolidated balance sheets. The table below summarizes, as of December 31, 2022, securities available for sale in an unrealized loss position for which an allowance for credit losses has not been recorded, aggregated by type of security and length of time in a continuous unrealized loss position. Less than 12 Months More than 12 Months Total Estimated Unrealized Estimated Unrealized Estimated Unrealized U.S. Treasury $ 2,012,129 $ 63,515 $ 3,039,458 $ 335,444 $ 5,051,587 $ 398,959 Residential mortgage-backed securities 3,265,658 345,307 2,495,906 603,331 5,761,564 948,638 States and political subdivisions 3,923,159 136,957 681,677 197,431 4,604,836 334,388 Total $ 9,200,946 $ 545,779 $ 6,217,041 $ 1,136,206 $ 15,417,987 $ 1,681,985 As of December 31, 2022, no allowance for credit losses has been recognized on available for sale securities in an unrealized loss position as management does not believe any of the securities are impaired due to reasons of credit quality. This is based upon our analysis of the underlying risk characteristics, including credit ratings, and other qualitative factors related to our available for sale securities and in consideration of our historical credit loss experience and internal forecasts. The issuers of these securities continue to make timely principal and interest payments under the contractual terms of the securities. Furthermore, management does not have the intent to sell any of the securities classified as available for sale in the table above and believes that it is more likely than not that we will not have to sell any such securities before a recovery of cost. The unrealized losses are due to increases in market interest rates over the yields available at the time the underlying securities were purchased. The fair value is expected to recover as the securities approach their maturity date or repricing date or if market yields for such investments decline. Contractual Maturities. The following table summarizes the maturity distribution schedule of securities held to maturity and securities available for sale as of December 31, 2022. Mortgage-backed securities are included in maturity categories based on their stated maturity date. Expected maturities may differ from contractual maturities because issuers may have the right to call or prepay obligations. Other securities classified as available for sale include stock in the Federal Reserve Bank and the Federal Home Loan Bank, which have no maturity date. These securities have been included in the total column only. Within 1 Year 1 - 5 Years 5 - 10 Years After 10 Years Total Held To Maturity Amortized Cost Residential mortgage-backed securities $ — $ — $ 514,059 $ 12,063 $ 526,122 States and political subdivisions 123,591 24,339 8,297 1,955,392 2,111,619 Other — 1,500 — — 1,500 Total $ 123,591 $ 25,839 $ 522,356 $ 1,967,455 $ 2,639,241 Estimated Fair Value Residential mortgage-backed securities $ — $ — $ 450,961 $ 9,839 $ 460,800 States and political subdivisions 123,505 24,292 8,286 1,849,551 2,005,634 Other — 1,431 — — 1,431 Total $ 123,505 $ 25,723 $ 459,247 $ 1,859,390 $ 2,467,865 Available For Sale Amortized Cost U. S. Treasury $ 249,363 $ 3,574,630 $ 1,434,504 $ 192,049 $ 5,450,546 Residential mortgage-backed securities 8 7,729 16,025 7,293,062 7,316,824 States and political subdivisions 261,477 1,464,493 937,127 4,435,538 7,098,635 Other — — — — 42,427 Total $ 510,848 $ 5,046,852 $ 2,387,656 $ 11,920,649 $ 19,908,432 Estimated Fair Value U. S. Treasury $ 240,361 $ 3,424,023 $ 1,244,812 $ 142,391 $ 5,051,587 Residential mortgage-backed securities 8 7,527 15,892 6,352,809 6,376,236 States and political subdivisions 261,888 1,470,098 918,563 4,122,806 6,773,355 Other — — — — 42,427 Total $ 502,257 $ 4,901,648 $ 2,179,267 $ 10,618,006 $ 18,243,605 Sales of Securities. Sales of securities available for sale were as follows: 2022 2021 2020 Proceeds from sales $ — $ 1,999,891 $ 1,162,352 Gross realized gains — 69 108,989 Gross realized losses — — — Tax benefit (expense) related to securities gains/losses — (14) (22,888) Premiums and Discounts. Premium amortization and discount accretion included in interest income on securities was as follows: 2022 2021 2020 Premium amortization $ (110,997) $ (121,994) $ (126,210) Discount accretion 13,597 2,752 2,425 Net (premium amortization) discount accretion $ (97,400) $ (119,242) $ (123,785) Trading Account Securities. Year-end trading account securities, at estimated fair value, were as follows: 2022 2021 U.S. Treasury $ 25,879 $ 24,237 States and political subdivisions 2,166 925 Total $ 28,045 $ 25,162 Net gains and losses on trading account securities were as follows: 2022 2021 2020 Net gain on sales transactions $ 3,129 $ 1,014 $ 1,102 Net mark-to-market gains (losses) (230) (75) 85 Net gain on trading account securities $ 2,899 $ 939 $ 1,187

Loans

Loans	12 Months Ended
Loans	Dec. 31, 2022
Receivables [Abstract]
Loans	Loans Year-end loans, including leases net of unearned discounts, consisted of the following: 2022 2021 Commercial and industrial $ 5,674,798 $ 5,364,954 Energy: Production 696,570 878,436 Service 133,542 105,901 Other 95,617 93,455 Total energy 925,729 1,077,792 Paycheck Protection Program 34,852 428,882 Commercial real estate: Commercial mortgages 6,168,910 5,867,062 Construction 1,477,247 1,304,271 Land 537,168 405,277 Total commercial real estate 8,183,325 7,576,610 Consumer real estate: Home equity lines of credit 691,841 519,098 Home equity loans 449,507 324,157 Home improvement loans 577,377 428,069 Other 124,814 139,466 Total consumer real estate 1,843,539 1,410,790 Total real estate 10,026,864 8,987,400 Consumer and other 492,726 477,369 Total loans $ 17,154,969 $ 16,336,397 Concentrations of Credit. Most of our lending activity occurs within the State of Texas, including the four largest metropolitan areas of Austin, Dallas/Ft. Worth, Houston and San Antonio, as well as other markets. The majority of our loan portfolio consists of commercial and industrial and commercial real estate loans. As of December 31, 2022 and 2021, there were no concentrations of loans related to any single industry in excess of 10% of total loans. At such dates, the largest industry concentration was related to the energy industry, which totaled 5.4% of total loans at December 31, 2022 and 6.6% of total loans at December 31, 2021. Unfunded commitments to extend credit and standby letters of credit issued to customers in the energy industry totaled $997.1 million and $103.4 million, respectively, as of December 31, 2022. Foreign Loans. We have U.S. dollar denominated loans and commitments to borrowers in Mexico. The outstanding balance of these loans and the unfunded amounts available under these commitments were not significant at December 31, 2022 or 2021. Overdrafts . Deposit account overdrafts reported as loans totaled $10.3 million and $7.8 million at December 31, 2022 and 2021. Related Party Loans . In the ordinary course of business, we have granted loans to certain directors, executive officers and their affiliates (collectively referred to as “related parties”). Activity in related party loans during 2022 is presented in the following table. Other changes were primarily related to changes in related-party status. Balance outstanding at December 31, 2021 $ 350,538 Principal additions 337,700 Principal payments (294,857) Other changes (2,126) Balance outstanding at December 31, 2022 $ 391,255 Accrued Interest Receivable. Accrued interest receivable on loans totaled $68.7 million and $40.0 million at December 31, 2022 and 2021, respectively and is included in accrued interest receivable and other assets in the accompany consolidated balance sheets. Non-Accrual and Past Due Loans. Loans are considered past due if the required principal and interest payments have not been received as of the date such payments were due. Loans are placed on non-accrual status when, in management’s opinion, the borrower may be unable to meet payment obligations as they become due, as well as when required by regulatory provisions. In determining whether or not a borrower may be unable to meet payment obligations for each class of loans, we consider the borrower’s debt service capacity through the analysis of current financial information, if available, and/or current information with regards to our collateral position. Regulatory provisions would typically require the placement of a loan on non-accrual status if (i) principal or interest has been in default for a period of 90 days or more unless the loan is both well secured and in the process of collection or (ii) full payment of principal and interest is not expected. Loans may be placed on non-accrual status regardless of whether or not such loans are considered past due. When interest accrual is discontinued, all unpaid accrued interest is reversed. Interest income on non-accrual loans is recognized only to the extent that cash payments are received in excess of principal due. A loan may be returned to accrual status when all the principal and interest amounts contractually due are brought current and future principal and interest amounts contractually due are reasonably assured, which is typically evidenced by a sustained period (at least six months) of repayment performance by the borrower. Year-end non-accrual loans, segregated by class of loans, were as follows: December 31, 2022 December 31, 2021 Total Non-Accrual Non-Accrual with No Credit Loss Allowance Total Non-Accrual Non-Accrual with No Credit Loss Allowance Commercial and industrial $ 18,130 $ 8,514 $ 22,582 $ 4,701 Energy 15,224 7,139 14,433 8,533 Commercial real estate: Buildings, land and other 3,552 1,991 15,297 13,817 Construction — — 948 — Consumer real estate 927 927 440 138 Consumer and other — — 13 13 Total $ 37,833 $ 18,571 $ 53,713 $ 27,202 The following tables present non-accrual loans as of December 31, 2022 and December 31, 2021 by class and year of origination. December 31, 2022 2022 2021 2020 2019 2018 Prior Revolving Loans Revolving Loans Converted to Term Total Commercial and industrial $ — $ 1,252 $ 1,089 $ 3,242 $ 1,197 $ 191 $ 2,973 $ 8,186 $ 18,130 Energy 4,657 — 72 1,386 10 — 7,631 1,468 15,224 Commercial real estate: Buildings, land and other 1,644 — — 217 266 1,425 — — 3,552 Construction — — — — — — — — — Consumer real estate — 258 — — — 84 — 585 927 Consumer and other — — — — — — — — — Total $ 6,301 $ 1,510 $ 1,161 $ 4,845 $ 1,473 $ 1,700 $ 10,604 $ 10,239 $ 37,833 December 31, 2021 2021 2020 2019 2018 2017 Prior Revolving Loans Revolving Loans Converted to Term Total Commercial and industrial $ 636 $ 3,856 $ 5,047 $ 1,820 $ 765 $ 353 $ 4,635 $ 5,470 $ 22,582 Energy — — 5,358 1,325 — — 6,931 819 14,433 Commercial real estate: Buildings, land and other 6,038 307 3,446 814 2,030 2,662 — — 15,297 Construction — 948 — — — — — — 948 Consumer real estate — — — — — 408 — 32 440 Consumer and other 13 — — — — — — — 13 Total $ 6,687 $ 5,111 $ 13,851 $ 3,959 $ 2,795 $ 3,423 $ 11,566 $ 6,321 $ 53,713 In the tables above, loans reported as 2022 originations as of December 31, 2022 and loans reported as 2021 originations as of December 31, 2021 were, for the most part, first originated in various years prior to 2022 and 2021, respectively, but were renewed in the respective year. Had non-accrual loans performed in accordance with their original contract terms, we would have recognized additional interest income, net of tax, of approximately $1.7 million in 2022, $1.8 million in 2021 and $2.9 million in 2020. An age analysis of past due loans (including both accruing and non-accruing loans), segregated by class of loans, as of December 31, 2022 is presented in the following table. Despite their past due status, Paycheck Protection Plan loans are fully guaranteed by the SBA. Loans Loans Total Past Current Total Loans Accruing Commercial and industrial $ 36,167 $ 12,853 $ 49,020 $ 5,625,778 $ 5,674,798 $ 5,560 Energy 2,880 7,680 10,560 915,169 925,729 — Paycheck Protection Program 5,321 13,867 19,188 15,664 34,852 13,867 Commercial real estate: Buildings, land and other 23,561 5,869 29,430 6,676,648 6,706,078 5,664 Construction — — — 1,477,247 1,477,247 — Consumer real estate 7,856 2,690 10,546 1,832,993 1,843,539 2,398 Consumer and other 5,155 311 5,466 487,260 492,726 311 Total $ 80,940 $ 43,270 $ 124,210 $ 17,030,759 $ 17,154,969 $ 27,800 Troubled Debt Restructurings . The restructuring of a loan is considered a “troubled debt restructuring” if both (i) the borrower is experiencing financial difficulties and (ii) the creditor has granted a concession. Concessions may include interest rate reductions or below market interest rates, principal forgiveness, restructuring amortization schedules, reductions in collateral and other actions intended to minimize potential losses. Troubled debt restructurings that occurred during 2022, 2021 and 2020 are set forth in the following table. 2022 2021 2020 Balance at Balance at Balance at Balance at Balance at Balance at Commercial and industrial $ — $ — $ 1,312 $ 1,162 $ 3,661 $ 192 Energy — — 3,817 721 2,432 2,421 Commercial real estate: Buildings, land and other 1,155 1,051 1,888 1,862 9,310 4,922 Construction — — — — 1,017 1,017 Consumer real estate — — — — — — Consumer and other — — — — 1,104 — $ 1,155 $ 1,051 $ 7,017 $ 3,745 $ 17,524 $ 8,552 Loan modifications are typically related to extending amortization periods, converting loans to interest only for a limited period of time, deferral of interest payments, waiver of certain covenants, consolidating notes and/or reducing collateral or interest rates. The modifications during the reported periods did not significantly impact our determination of the allowance for credit losses on loans. Additional information related to restructured loans was as follows: 2022 2021 2020 Restructured loans past due in excess of 90 days at period-end: Number of loans — 2 1 Dollar amount of loans $ — $ 1,027 $ 2,008 Restructured loans on non-accrual status at period end 1,051 3,439 8,552 Charge-offs of restructured loans: Recognized in connection with restructuring — — 337 Recognized on previously restructured loans 723 4,278 3,894 Proceeds from sale of restructured loans 1,070 — — Credit Quality Indicators. As part of the on-going monitoring of the credit quality of our loan portfolio, management tracks certain credit quality indicators including trends related to (i) the weighted-average risk grade of commercial loans, (ii) the level of classified commercial loans, (iii) the delinquency status of consumer loans (iv) non-performing loans (see details above) and (vi) the general economic conditions in the State of Texas. We utilize a risk grading matrix to assign a risk grade to each of our commercial loans. Loans are graded on a scale of 1 to 14. A description of the general characteristics of the 14 risk grades is as follows: • Grades 1, 2 and 3 - These grades include loans to very high credit quality borrowers of investment or near investment grade. These borrowers are generally publicly traded (grades 1 and 2), have significant capital strength, moderate leverage, stable earnings and growth, and readily available financing alternatives. Smaller entities, regardless of strength, would generally not fit in these grades. • Grades 4 and 5 - These grades include loans to borrowers of solid credit quality with moderate risk. Borrowers in these grades are differentiated from higher grades on the basis of size (capital and/or revenue), leverage, asset quality and the stability of the industry or market area. • Grades 6, 7 and 8 - These grades include “pass grade” loans to borrowers of acceptable credit quality and risk. Such borrowers are differentiated from Grades 4 and 5 in terms of size, secondary sources of repayment or they are of lesser stature in other key credit metrics in that they may be over-leveraged, under capitalized, inconsistent in performance or in an industry or an economic area that is known to have a higher level of risk, volatility, or susceptibility to weaknesses in the economy. • Grade 9 - This grade includes loans on management’s “watch list” and is intended to be utilized on a temporary basis for pass grade borrowers where a significant risk-modifying action is anticipated in the near term. • Grade 10 - This grade is for “Other Assets Especially Mentioned” in accordance with regulatory guidelines. This grade is intended to be temporary and includes loans to borrowers whose credit quality has clearly deteriorated and are at risk of further decline unless active measures are taken to correct the situation. • Grade 11 - This grade includes “Substandard” loans, in accordance with regulatory guidelines, for which the accrual of interest has not been stopped. By definition under regulatory guidelines, a “Substandard” loan has defined weaknesses which make payment default or principal exposure likely, but not yet certain. Such loans are apt to be dependent upon collateral liquidation, a secondary source of repayment or an event outside of the normal course of business. • Grade 12 - This grade includes “Substandard” loans, in accordance with regulatory guidelines, for which the accrual of interest has been stopped. This grade includes loans where interest is more than 120 days past due and not fully secured and loans where a specific valuation allowance may be necessary, but generally does not exceed 30% of the principal balance. • Grade 13 - This grade includes “Doubtful” loans in accordance with regulatory guidelines. Such loans are placed on non-accrual status and may be dependent upon collateral having a value that is difficult to determine or upon some near-term event which lacks certainty. Additionally, these loans generally have a specific valuation allowance in excess of 30% of the principal balance. • Grade 14 - This grade includes “Loss” loans in accordance with regulatory guidelines. Such loans are to be charged-off or charged-down when payment is acknowledged to be uncertain or when the timing or value of payments cannot be determined. “Loss” is not intended to imply that the loan or some portion of it will never be paid, nor does it in any way imply that there has been a forgiveness of debt. In monitoring credit quality trends in the context of assessing the appropriate level of the allowance for credit losses on loans, we monitor portfolio credit quality by the weighted-average risk grade of each class of commercial loan. Individual relationship managers, under the oversight of credit administration, review updated financial information for all pass grade loans to reassess the risk grade on at least an annual basis. When a loan has a risk grade of 9, it is still considered a pass grade loan; however, it is considered to be on management’s “watch list,” where a significant risk-modifying action is anticipated in the near term. When a loan has a risk grade of 10 or higher, a special assets officer monitors the loan on an on-going basis. The following tables present weighted-average risk grades for all commercial loans, by class and year of origination/renewal as of December 31, 2022 and 2021. Paycheck Protection Program (“PPP”) loans are excluded as such loans are fully guaranteed by the Small Business Administration (“SBA”). December 31, 2022 2022 2021 2020 2019 2018 Prior Revolving Loans Revolving Loans Converted to Term Total Commercial and industrial Risk grades 1-8 $ 1,667,274 $ 618,756 $ 485,908 $ 226,835 $ 123,768 $ 192,791 $ 2,068,891 $ 51,694 $ 5,435,917 Risk grade 9 31,275 34,950 3,651 5,400 11,006 1,014 54,856 4,040 146,192 Risk grade 10 2,294 724 845 4,713 1,341 114 23,880 3,685 37,596 Risk grade 11 2,342 1,357 6,720 1,807 1,229 1,644 19,582 2,282 36,963 Risk grade 12 — 1,052 866 2,972 1,177 191 673 5,590 12,521 Risk grade 13 — 200 223 270 20 — 2,300 2,596 5,609 $ 1,703,185 $ 657,039 $ 498,213 $ 241,997 $ 138,541 $ 195,754 $ 2,170,182 $ 69,887 $ 5,674,798 W/A risk grade 6.37 7.05 6.01 6.59 6.87 5.55 6.26 7.68 6.39 Energy Risk grades 1-8 $ 338,050 $ 99,089 $ 4,917 $ 3,138 $ 2,020 $ 2,850 $ 393,957 $ 43,161 $ 887,182 Risk grade 9 1,561 1,611 166 562 748 — 6,434 30 11,112 Risk grade 10 — — — 428 214 — — — 642 Risk grade 11 7,956 162 157 3,145 86 63 — — 11,569 Risk grade 12 3,995 — 72 1,386 10 — 4,571 806 10,840 Risk grade 13 662 — — — — — 3,060 662 4,384 $ 352,224 $ 100,862 $ 5,312 $ 8,659 $ 3,078 $ 2,913 $ 408,022 $ 44,659 $ 925,729 W/A risk grade 6.09 5.65 7.65 9.64 8.02 6.59 5.18 5.69 5.67 Commercial real estate: Buildings, land, other Risk grades 1-8 $ 1,811,069 $ 1,484,811 $ 956,567 $ 708,942 $ 360,154 $ 800,944 $ 111,778 $ 105,763 $ 6,340,028 Risk grade 9 52,288 13,139 36,264 22,086 17,699 45,590 652 2,210 189,928 Risk grade 10 26,688 11,150 3,735 9,008 29,683 5,221 5,535 — 91,020 Risk grade 11 10,199 19,073 12,631 4,778 2,525 28,841 2,993 510 81,550 Risk grade 12 1,049 — — 217 266 1,425 — — 2,957 Risk grade 13 595 — — — — — — — 595 $ 1,901,888 $ 1,528,173 $ 1,009,197 $ 745,031 $ 410,327 $ 882,021 $ 120,958 $ 108,483 $ 6,706,078 W/A risk grade 7.01 7.26 7.14 7.01 7.33 6.94 7.38 6.43 7.09 Construction Risk grades 1-8 $ 640,948 $ 489,391 $ 128,788 $ 2,236 $ 486 $ 1,726 $ 163,293 $ 3,144 $ 1,430,012 Risk grade 9 12,865 2,100 2,100 — — — 17,887 — 34,952 Risk grade 10 859 72 — — — — — — 931 Risk grade 11 11,352 — — — — — — — 11,352 Risk grade 12 — — — — — — — — — Risk grade 13 — — — — — — — — — $ 666,024 $ 491,563 $ 130,888 $ 2,236 $ 486 $ 1,726 $ 181,180 $ 3,144 $ 1,477,247 W/A risk grade 7.29 7.03 6.43 7.04 6.00 6.76 7.23 5.03 7.12 Total commercial real estate $ 2,567,912 $ 2,019,736 $ 1,140,085 $ 747,267 $ 410,813 $ 883,747 $ 302,138 $ 111,627 $ 8,183,325 W/A risk grade 7.08 7.20 7.06 7.01 7.33 6.94 7.29 6.39 7.10 December 31, 2021 2021 2020 2019 2018 2017 Prior Revolving Loans Revolving Loans Converted to Term Total Commercial and industrial Risk grades 1-8 $ 1,567,883 $ 657,529 $ 350,563 $ 179,209 $ 146,064 $ 131,201 $ 1,987,061 $ 44,337 $ 5,063,847 Risk grade 9 32,866 21,094 24,683 26,327 612 11,419 65,131 5,738 187,870 Risk grade 10 27,961 6,273 4,047 4,357 1,021 98 14,091 1,289 59,137 Risk grade 11 1,178 4,572 8,068 2,450 2,460 221 4,714 7,855 31,518 Risk grade 12 456 2,495 3,828 1,756 347 353 613 2,687 12,535 Risk grade 13 180 1,361 1,219 64 418 — 4,022 2,783 10,047 $ 1,630,524 $ 693,324 $ 392,408 $ 214,163 $ 150,922 $ 143,292 $ 2,075,632 $ 64,689 $ 5,364,954 W/A risk grade 5.91 6.30 6.89 7.06 5.91 5.80 6.21 8.04 6.22 Energy Risk grades 1-8 $ 445,489 $ 8,075 $ 9,259 $ 6,441 $ 3,110 $ 4,368 $ 464,454 $ 67,174 $ 1,008,370 Risk grade 9 19,274 611 1,775 187 — 724 11,635 2,416 36,622 Risk grade 10 — 101 631 511 — — — 530 1,773 Risk grade 11 10,260 752 3,968 1,016 — 546 — 52 16,594 Risk grade 12 — — 3,888 246 — — 4,000 819 8,953 Risk grade 13 — — 1,470 1,079 — — 2,931 — 5,480 $ 475,023 $ 9,539 $ 20,991 $ 9,480 $ 3,110 $ 5,638 $ 483,020 $ 70,991 $ 1,077,792 W/A risk grade 6.21 7.81 9.34 8.60 7.12 7.63 5.61 6.46 6.06 Commercial real estate: Buildings, land, other Risk grades 1-8 $ 1,707,550 $ 1,096,274 $ 874,130 $ 533,362 $ 492,492 $ 713,268 $ 52,150 $ 105,696 $ 5,574,922 Risk grade 9 16,302 145,340 52,427 43,806 27,188 27,767 4,445 4,258 321,533 Risk grade 10 28,209 13,813 69,643 46,250 64,950 46,582 — — 269,447 Risk grade 11 3,455 1,321 8,720 7,788 26,107 34,970 3,000 5,779 91,140 Risk grade 12 5,838 307 3,446 814 2,030 2,662 — — 15,097 Risk grade 13 200 — — — — — — — 200 $ 1,761,554 $ 1,257,055 $ 1,008,366 $ 632,020 $ 612,767 $ 825,249 $ 59,595 $ 115,733 $ 6,272,339 W/A risk grade 7.19 7.18 7.35 7.39 7.34 7.01 7.06 7.02 7.22 Construction Risk grades 1-8 $ 657,471 $ 262,176 $ 178,226 $ 2,339 $ 38 $ 1,930 $ 160,020 $ — $ 1,262,200 Risk grade 9 35,721 4,956 — — 446 — — — 41,123 Risk grade 10 — — — — — — — — — Risk grade 11 — — — — — — — — — Risk grade 12 — 748 — — — — — — 748 Risk grade 13 — 200 — — — — — — 200 $ 693,192 $ 268,080 $ 178,226 $ 2,339 $ 484 $ 1,930 $ 160,020 $ — $ 1,304,271 W/A risk grade 7.17 6.56 7.60 7.51 8.92 6.73 6.79 — 7.06 Total commercial real estate $ 2,454,746 $ 1,525,135 $ 1,186,592 $ 634,359 $ 613,251 $ 827,179 $ 219,615 $ 115,733 $ 7,576,610 W/A risk grade 7.18 7.07 7.39 7.39 7.34 7.00 6.86 7.02 7.19 At December 31, 2022 and 2021, the weighted-average risk grades for “pass grade” (risk grades 1-8) loans were 6.24 and 6.01, respectively, for commercial and industrial; 5.44 and 5.78, respectively, for energy; 6.94 and 6.91, respectively, for commercial real estate - buildings, land and other; and 7.04 and 6.99, respectively, for commercial real estate - construction. Furthermore, in the tables above, there are loans reported as 2022 originations as of December 31, 2022 and 2021 originations as of December 31, 2021 that have risk grades of 11 or higher. These loans were, for the most part, first originated in various years prior to 2022 and 2021, respectively, but were renewed in the respective year. Information about the payment status of consumer loans, segregated by portfolio segment and year of origination, as of December 31, 2022 and December 31, 2021 was as follows: December 31, 2022 2022 2021 2020 2019 2018 Prior Revolving Loans Revolving Loans Converted to Term Total Consumer real estate: Past due 30-89 days $ 793 $ 1,125 $ 645 $ 936 $ 503 $ 2,087 $ 565 $ 1,202 $ 7,856 Past due 90 or more days 95 258 28 — 129 919 347 914 2,690 Total past due 888 1,383 673 936 632 3,006 912 2,116 10,546 Current loans 403,587 313,222 194,900 70,723 38,904 122,585 678,418 10,654 1,832,993 Total $ 404,475 $ 314,605 $ 195,573 $ 71,659 $ 39,536 $ 125,591 $ 679,330 $ 12,770 $ 1,843,539 Consumer and other: Past due 30-89 days $ 2,673 $ 511 $ 128 $ 51 $ 4 $ 31 $ 314 $ 1,443 $ 5,155 Past due 90 or more days 77 2 — 13 — — 25 194 311 Total past due 2,750 513 128 64 4 31 339 1,637 5,466 Current loans 59,886 20,887 6,475 2,897 1,271 1,632 372,117 22,095 487,260 Total $ 62,636 $ 21,400 $ 6,603 $ 2,961 $ 1,275 $ 1,663 $ 372,456 $ 23,732 $ 492,726 December 31, 2021 2021 2020 2019 2018 2017 Prior Revolving Loans Revolving Loans Converted to Term Total Consumer real estate: Past due 30-89 days $ 280 $ 204 $ 406 $ 489 $ 296 $ 1,344 $ 126 $ 1,732 $ 4,877 Past due 90 or more days — — — 154 355 828 991 185 2,513 Total past due 280 204 406 643 651 2,172 1,117 1,917 7,390 Current loans 319,042 251,160 95,900 55,893 48,841 116,423 505,333 10,808 1,403,400 Total $ 319,322 $ 251,364 $ 96,306 $ 56,536 $ 49,492 $ 118,595 $ 506,450 $ 12,725 $ 1,410,790 Consumer and other: Past due 30-89 days $ 1,600 $ 91 $ 120 $ 38 $ 51 $ 17 $ 325 $ 1,943 $ 4,185 Past due 90 or more days 548 — 45 — — — 34 449 1,076 Total past due 2,148 91 165 38 51 17 359 2,392 5,261 Current loans 46,708 17,843 6,215 2,684 1,708 1,158 371,866 23,926 472,108 Total $ 48,856 $ 17,934 $ 6,380 $ 2,722 $ 1,759 $ 1,175 $ 372,225 $ 26,318 $ 477,369 Revolving loans that converted to term during 2022 and 2021 were as follows: 2022 2021 Commercial and industrial $ 34,247 $ 40,099 Energy 3,295 54,996 Commercial real estate: Buildings, land and other 12,174 68,337 Construction 3,144 — Consumer real estate 5,381 1,156 Consumer and other 9,200 8,367 Total $ 67,441 $ 172,955 In assessing the general economic conditions in the State of Texas, management monitors and tracks the Texas Leading Index (“TLI”), which is produced by the Federal Reserve Bank of Dallas. The TLI is a single summary statistic that is designed to signal the likelihood of the Texas economy’s transition from expansion to recession and vice versa. Management believes this index provides a reliable indication of the direction of overall credit quality. The TLI is a composite of the following eight leading indicators: (i) Texas Value of the Dollar, (ii) U.S. Leading Index, (iii) real oil prices (iv) well permits, (v) initial claims for unemployment insurance, (vi) Texas Stock Index, (vii) Help-Wanted Index and (viii) average weekly hours worked in manufacturing. The TLI totaled 129.7 at December 31, 2022 and 135.7 at December 31, 2021. A lower TLI value implies less favorable economic conditions. Allowance For Credit Losses - Loans. The allowance for credit losses on loans is a contra-asset valuation account, calculated in accordance with ASC 326, that is deducted from the amortized cost basis of loans to present the net amount expected to be collected. The amount of the allowance represents management's best estimate of current expected credit losses on loans considering available information, from internal and external sources, relevant to assessing collectibility over the loans' contractual terms, adjusted for expected prepayments when appropriate. The contractual term excludes expected extensions, renewals and modifications unless (i) management has a reasonable expectation that a loan to an individual borrower that is experiencing financial difficulty will be modified or (ii) such extension or renewal options are not unconditionally cancellable by us and, in such cases, the borrower is likely to meet applicable conditions and likely to request extension or renewal. Relevant available information includes historical credit loss experience, current conditions and reasonable and supportable forecasts. While historical credit loss experience provides the basis for the estimation of expected credit losses, adjustments to historical loss information may be made for differences in current portfolio-specific risk characteristics, environmental conditions or other relevant factors. The allowance for credit losses is measured on a collective basis for portfolios of loans when similar risk characteristics exist. Loans that do not share risk characteristics are evaluated for expected credit losses on an individual basis and excluded from the collective evaluation. Expected credit losses for collateral dependent loans, including loans where the borrower is experiencing financial difficulty but foreclosure is not probable, are based on the fair value of the collateral at the reporting date, adjusted for selling costs as appropriate. Credit loss expense related to loans reflects the totality of actions taken on all loans for a particular period including any necessary increases or decreases in the allowance related to changes in credit loss expectations associated with specific loans or pools of loans. Portions of the allowance may be allocated for specific credits; however, the entire allowance is available for any credit that, in management’s judgment, should be charged off. While management utilizes its best judgment and information available, the ultimate appropriateness of the allowance is dependent upon a variety of factors beyond our control, including the performance of our loan portfolio, the economy, changes in interest rates and the view of the regulatory authorities toward loan classifications. In calculating the allowance for credit losses, most loans are segmented into pools based upon similar characteristics and risk profiles. Common characteristics and risk profiles include the type/purpose of loan, underlying collateral, geographical similarity and historical/expected credit loss patterns. In developing these loan pools for the purposes of modeling expected credit losses, we also analyzed the degree of correlation in how loans within each portfolio respond when subjected to varying economic conditions and scenarios as well as other portfolio stress factors. For modeling purposes, our loan pools include (i) commercial and industrial and energy - non-revolving, (ii) commercial and industrial and energy - revolving, (iii) commercial real estate - owner occupied, (iv) commercial real estate - non-owner occupied, (v) commercial real estate - construction/land development, (vi) consumer real estate and (vii) consumer and other. We periodically reassess each pool to ensure the loans within the pool continue to share similar characteristics and risk profiles and to determine whether further segmentation is necessary. For each loan pool, we measure expected credit losses over the life of each loan utilizing a combination of models which measure (i) probability of default (“PD”), which is the likelihood that loan will stop performing/default, (ii) probability of attrition (“PA”), which is the likelihood that a loan will pay-off prior to maturity, (iii) loss given default (“LGD”), which is the expected loss rate for loans in default and (iv) exposure at default (“EAD”), which is the estimated outstanding principal balance of the loans upon default, including the expected funding of unfunded commitments outstanding as of the measurement date. For certain commercial loan portfolios, the PD is calculated using a transition matrix to determine the likelihood of a customer’s risk grade migrating from one specified range of risk grades to a different specified range. Expected credit losses are calculated as the product of PD (adjusted for attrition), LGD and EAD. This methodology builds on default probabilities already incorporated into our risk grading process by utilizing pool-specific historical loss rates to calculate expected credit losses. These pool-specific historical loss rates may be adjusted for current macroeconomic assumptions, as further discussed below, and other factors such as differences in underwriting standards, portfolio mix, or when historical asset terms do not reflect the contractual terms of the financial assets being evaluated as of the measurement date. Each time we measure expected credit losses, we assess the relevancy of historical loss information and consider any necessary adjustments to address any differences in asset-specific characteristics. Due to their short-term nature, expected credit losses for overdrafts included in consumer and other loans are based solely upon a weighting of recent historical charge-offs over a period of three years. The measurement of expected credit losses is impacted by loan/borrower attributes and certain macroeconomic variables. Significant loan/borrower attributes utilized in our modeling processes include, among other things, (i) origination date, (ii) maturity date, (iii) payment type, (iv) collateral type and amount, (v) current risk grade, (vi) current unpaid balance and commitment utilization rate, (vii) payment status/delinquency history and (viii) expected recoveries of previously charged-off amounts. Significant macroeconomic variables utilized in our modeling processes include, among other things, (i) Gross State Product for Texas and U.S. Gross Domestic Product, (ii) selected market interest rates including U.S. Treasury rates, bank prime rate, 30-year fixed mortgage rate, BBB corporate bond rate, among others, (iii) unemployment rates, (iv) commercial and residential property prices in Texas and the U.S. as a whole, (v) West Texas Intermediate crude oil price and (vi) total stock market index. PD and PA were estimated by analyzing internally-sourced data related to historical performance of each loan pool over a complete economic cycle. PD and PA are adjusted to reflect the current impact of certain macroeconomic variables as well as their expected changes over a reasonable and supportable forecast period. We have determined that we are reasonably able to forecast the macroeconomic variables used in our modeling processes with an acceptable degree of confidence for a total of two years with the last twelve months of the forecast period encompassing a reversion process whereby the forecasted macroeconomic variables are reverted to their historical mean utilizing a rational, systematic basis. The macroeconomic variables utilized as inputs in our modeling processes were subjected to a variety of analysis procedures and were selected primarily based on statistical relevancy and correlation to our historical credit losses. By reverting these modeling inputs to their historical mean and considering loan/borrower specific attributes, our models are intended to yield a measurement of expected credit losses that reflects our average historical loss rates for periods subsequent to the twelve-month reversion period. The LGD is based on historical recovery averages for each loan pool, adjusted to reflect the current impact of certain macroeconomic variables as well as their expected changes over a two-year forecast period, with the final twelve months of the forecast period encompassing a reversion process, which management considers to be both reasonable and supportable. This same forecast/reversion period is used for all macroeconomic variables used in all of our models. EAD is estimated using a linear regression model that estimates the average percentage of the loan balance that remains at the time of a default event. Management qualitatively adjusts model results for risk factors that are not considered within our modeling processes but are nonetheless relevant in assessing the expected credit losses within our loan pools. These qualitative factor (“Q-Factor”) and other qualitative adjustments may increase or decrease management's estimate of expected credit losses by a calculated percentage or amount based upon the estimated level of risk. The various risks that may be considered in making Q-Factor and other qualitative adjustments include, among other things, the impact of (i) changes in lending policies and procedures, including changes in underwriting standards and practices for collections, write-offs, and recoveries, (ii) actual and expected changes in international, national, regional, and local economic and business conditions and developments that affect the collectibility of the loan pools, (iii) changes in the nature and volume of the loan pools and in th

Premises and Equipment

Premises and Equipment	12 Months Ended
Premises and Equipment	Dec. 31, 2022
Property, Plant and Equipment [Abstract]
Premises and Equipment	Premises and Equipment and Lease Commitments Year-end premises and equipment were as follows: 2022 2021 Land $ 170,938 $ 152,219 Buildings 521,280 495,903 Technology, furniture and equipment 236,440 256,323 Leasehold improvements 209,398 192,207 Construction and projects in progress 39,506 14,513 Lease right-of-use assets 288,816 281,438 1,466,378 1,392,603 Less accumulated depreciation and amortization (363,683) (342,272) Total premises and equipment, net $ 1,102,695 $ 1,050,331 Depreciation of premises and equipment totaled $57.4 million in 2022, $55.1 million 2021 and $49.9 million in 2020. Lease Commitments . We lease certain office facilities and office equipment under operating leases. Rent expense for all operating leases totaled $47.7 million in 2022, $45.6 million in 2021 and $46.0 million in 2020. The components of total lease expense in 2022 and 2021 were as follows: 2022 2021 Amortization of lease right-of-use assets $ 33,285 $ 32,811 Short-term lease expense 2,208 1,595 Non-lease components (including taxes, insurance, common maintenance, etc.) 12,172 11,203 Total $ 47,665 $ 45,609 Right-of-use lease assets totaled $288.8 million and $281.4 million at December 31, 2022 and 2021, respectively, and are reported as a component of premises and equipment on our accompanying consolidated balance sheets. The related lease liabilities totaled $321.9 million and $313.4 million at December 31, 2022 and 2021, respectively, and are reported as a component of accrued interest payable and other liabilities in the accompanying consolidated balance sheets. Lease payments under operating leases that were applied to our operating lease liability totaled $32.9 million during 2022 and $32.1 million during 2021. The following table reconciles future undiscounted lease payments due under non-cancelable operating leases (those amounts subject to recognition) to the aggregate operating lessee lease liability as of December 31, 2022: Future lease payments 2023 $ 33,685 2024 33,651 2025 33,990 2026 33,600 2027 32,023 Thereafter 232,905 Total undiscounted operating lease liability 399,854 Imputed interest 77,909 Total operating lease liability included in the accompanying balance sheet $ 321,945 Weighted-average lease term in years 13.62 Weighted-average discount rate 3.13%

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	12 Months Ended
Goodwill and Other Intangible Assets	Dec. 31, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets Goodwill . Year-end goodwill was as follows: 2022 2021 Goodwill $ 654,952 $ 654,952 Other Intangible Assets. Year-end other intangible assets were as follows: Gross Accumulated Net 2022 Core deposits $ 9,300 $ (8,990) $ 310 Customer relationships 1,521 (1,445) 76 $ 10,821 $ (10,435) $ 386 2021 Core deposits $ 9,300 $ (8,582) $ 718 Customer relationships 2,385 (2,237) 148 $ 11,685 $ (10,819) $ 866 Other intangible assets are amortized on an accelerated basis over their estimated lives, which range from 5 to 10 years. Amortization expense related to intangible assets totaled $480 thousand in 2022, $697 thousand in 2021, and $918 thousand in 2020. The estimated aggregate future amortization expense for intangible assets remaining as of December 31, 2022 is as follows: 2023 $ 283 2024 87 2025 11 2026 5 $ 386

Deposits

Deposits	12 Months Ended
Deposits	Dec. 31, 2022
Deposits [Abstract]
Deposits	Deposits Year-end deposits were as follows: 2022 2021 Non-interest-bearing demand deposits $ 17,598,234 $ 18,423,018 Interest-bearing deposits: Savings and interest checking 12,333,675 11,930,959 Money market accounts 12,227,247 11,228,815 Time accounts 1,795,040 1,112,904 Total interest-bearing deposits 26,355,962 24,272,678 Total deposits $ 43,954,196 $ 42,695,696 The following table presents additional information about our year-end deposits: 2022 2021 Deposits from foreign sources (primarily Mexico) $ 1,048,943 $ 993,479 Non-interest-bearing public funds deposits 788,040 1,235,026 Interest-bearing public funds deposits 758,761 810,863 Total deposits not covered by deposit insurance 23,839,797 24,125,359 Time deposits not covered by deposit insurance 430,128 238,608 Deposits from certain directors, executive officers and their affiliates 153,083 276,556 Scheduled maturities of time deposits at December 31, 2022 were as follows: 2023 $ 1,381,519 2024 413,521 $ 1,795,040 Scheduled maturities of time deposits not covered by deposit insurance at December 31, 2022, were as follows: Due within 3 months or less $ 87,254 Due after 3 months and within 6 months 87,035 Due after 6 months and within 12 months 131,503 Due after 12 months 124,336 $ 430,128

Borrowed Funds

Borrowed Funds	12 Months Ended
Borrowed Funds	Dec. 31, 2022
Debt Disclosure [Abstract]
Borrowed Funds	Borrowed Funds Federal Funds Purchased and Securities Sold Under Agreements to Repurchase. Federal funds purchased are short-term borrowings that typically mature within one ninety thirty ninety Subordinated Notes. In March 2017, we issued $100 million of 4.50% subordinated notes that mature on March 17, 2027. The notes, which qualify as Tier 2 capital for Cullen/Frost, bear interest at the rate of 4.50% per annum, payable semi-annually on each March 17 and September 17. The notes are unsecured and subordinated in right of payment to the payment of our existing and future senior indebtedness and structurally subordinated to all existing and future indebtedness of our subsidiaries. Unamortized debt issuance costs related to these notes, totaled approximately $665 thousand and $822 thousand December 31, 2022 and 2021. Proceeds from sale of the notes were used for general corporate purposes. Junior Subordinated Deferrable Interest Debentures. At December 31, 2022 and 2021, we had $123.7 million of junior subordinated deferrable interest debentures issued to Cullen/Frost Capital Trust II (“Trust II”), a wholly owned Delaware statutory business trust. Unamortized debt issuance costs related to Trust II totaled $643 thousand and $701 thousand at December 31, 2022 and 2021. In October 2021, we redeemed $13.4 million of junior subordinated deferrable interest debentures issued to WNB Capital Trust I (“WNB Trust”), a wholly owned Delaware statutory business trust acquired in connection with the acquisition of WNB Bancshares, Inc. (“WNB”) in 2014. Trust II is a variable interest entity for which we are not the primary beneficiary and, as such, its accounts are not included in our consolidated financial statements. This was also the case with WNB Trust prior to its dissolution in 2021. See Note 1 - Summary of Significant Accounting Policies for additional information about our consolidation policy. Details of our transactions with the capital trust are presented below. Trust II was formed in 2004 for the purpose of issuing $120.0 million of floating rate (three-month LIBOR plus a margin of 1.55%) trust preferred securities, which represent beneficial interests in the assets of the trust. The trust preferred securities will mature on March 1, 2034 and are currently redeemable with the approval of the Federal Reserve Board in whole or in part at our option. Distributions on the trust preferred securities are payable quarterly in arrears on March 1, June 1, September 1 and December 1 of each year. Trust II also issued $3.7 million of common equity securities to Cullen/Frost. The proceeds of the offering of the trust preferred securities and common equity securities were used to purchase $123.7 million of floating rate (three-month LIBOR plus a margin of 1.55%, which was equal to 6.31% and 1.72% at December 31, 2022 and 2021) junior subordinated deferrable interest debentures issued by us, which have terms substantially similar to the trust preferred securities. We have the right at any time during the term of the debentures issued to Trust II to defer payments of interest at any time or from time to time for an extension period not exceeding 20 consecutive quarterly periods with respect to each extension period. Under the terms of the debentures, in the event that under certain circumstances there is an event of default under the debentures or we have elected to defer interest on the debentures, we may not, with certain exceptions, declare or pay any dividends or distributions on our capital stock or purchase or acquire any of our capital stock. Payments of distributions on the trust preferred securities and payments on redemption of the trust preferred securities are guaranteed by us on a limited basis. We are obligated by agreement to pay any costs, expenses or liabilities of Trust II other than those arising under the trust preferred securities. Our obligations under the junior subordinated debentures, the related indenture, the trust agreement establishing the trust, the guarantee and the agreement as to expenses and liabilities, in the aggregate, constitute a full and unconditional guarantee by us of Trust II’s obligations under the trust preferred securities. Although the accounts of Trust II are not included in our consolidated financial statements, the trust preferred securities issued by Trust II are included in the capital of Cullen/Frost for regulatory capital purposes. See Note 9 - Capital and Regulatory Matters.

Off-Balance-Sheet Arrangements,

Off-Balance-Sheet Arrangements, Commitments, Guarantees and Contingencies	12 Months Ended
	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Off-Balance-Sheet Arrangements, Commitments, Guarantees and Contingencies	Off-Balance-Sheet Arrangements, Commitments, Guarantees and Contingencies Financial Instruments with Off-Balance-Sheet Risk . In the normal course of business, we enter into various transactions, which, in accordance with generally accepted accounting principles in the United States, are not included in our consolidated balance sheets. We enter into these transactions to meet the financing needs of our customers. These transactions include commitments to extend credit and standby letters of credit, which involve, to varying degrees, elements of credit risk and interest rate risk in excess of the amounts recognized in the consolidated balance sheets. We minimize our exposure to loss under these commitments by subjecting them to credit approval and monitoring procedures. We enter into contractual commitments to extend credit, normally with fixed expiration dates or termination clauses, at specified rates and for specific purposes. Substantially all of our commitments to extend credit are contingent upon customers maintaining specific credit standards at the time of loan funding. Standby letters of credit are written conditional commitments issued by us to guarantee the performance of a customer to a third party. In the event the customer does not perform in accordance with the terms of the agreement with the third party, we would be required to fund the commitment. The maximum potential amount of future payments we could be required to make is represented by the contractual amount of the commitment. If the commitment were funded, we would be entitled to seek recovery from the customer. Our policies generally require that standby letter of credit arrangements contain security and debt covenants similar to those contained in loan agreements. We consider the fees collected in connection with the issuance of standby letters of credit to be representative of the fair value of our obligation undertaken in issuing the guarantee. In accordance with applicable accounting standards related to guarantees, we defer fees collected in connection with the issuance of standby letters of credit. The fees are then recognized in income proportionately over the life of the standby letter of credit agreement. The deferred standby letter of credit fees represent the fair value of our potential obligations under the standby letter of credit guarantees. Year-end financial instruments with off-balance-sheet risk are presented in the following table. Commitments and standby letters of credit are presented at contractual amounts; however, since many of these commitments are expected to expire unused or only partially used, the total amounts of these commitments do not necessarily reflect future cash requirements. 2022 2021 Commitments to extend credit $ 12,137,957 $ 10,420,142 Standby letters of credit 383,851 238,690 Deferred standby letter of credit fees 2,236 2,072 Allowance For Credit Losses - Off-Balance-Sheet Credit Exposures. The allowance for credit losses on off-balance-sheet credit exposures is a liability account, calculated in accordance with ASC 326, representing expected credit losses over the contractual period for which we are exposed to credit risk resulting from a contractual obligation to extend credit. No allowance is recognized if we have the unconditional right to cancel the obligation. Off-balance-sheet credit exposures primarily consist of amounts available under outstanding lines of credit and letters of credit detailed in the table above. For the period of exposure, the estimate of expected credit losses considers both the likelihood that funding will occur and the amount expected to be funded over the estimated remaining life of the commitment or other off-balance-sheet exposure. The likelihood and expected amount of funding are based on historical utilization rates. The amount of the allowance represents management's best estimate of expected credit losses on commitments expected to be funded over the contractual life of the commitment. Estimating credit losses on amounts expected to be funded uses the same methodology as described for loans in Note 3 - Loans as if such commitments were funded. The following table details activity in the allowance for credit losses on off-balance-sheet credit exposures. 2022 2021 2020 Beginning balance $ 50,314 $ 44,152 $ 500 Impact of adopting ASC 326 — — 39,377 Credit loss expense 8,279 6,162 4,275 Ending balance $ 58,593 $ 50,314 $ 44,152 Credit Card Guarantees . We guarantee the credit card debt of certain customers to the merchant bank that issues the cards. At December 31, 2022 and 2021, the guarantees totaled approximately $8.0 million and $8.6 million, of which amounts, $897 thousand and $962 thousand were fully collateralized. Trust Accounts . We hold certain assets which are not included in our consolidated balance sheets including assets held in fiduciary or custodial capacity on behalf of our trust customers. The estimated fair value of trust assets was approximately $43.6 billion and $43.3 billion at December 31, 2022 and 2021, respectively. These assets are primarily composed of equity securities, fixed income securities, alternative investments and cash equivalents, among other things. Executive Change-In-Control Severance Plan . We maintain a change-in-control severance plan for the benefit of certain executive officers. Under this plan, each covered person could receive, upon the effectiveness of a change-in-control, two to three times (depending on the person) their base compensation plus the target bonus established for the year, and any unpaid base salary and pro rata target bonus for the year in which the termination occurs, including vacation pay. Additionally, the executive’s insurance benefits will continue for two to three full years after the termination and all long-term incentive awards will immediately vest. Litigation . We are subject to various claims and legal actions that have arisen in the course of conducting business. Management does not expect the ultimate disposition of these matters to have a material adverse impact on our financial statements.

Capital and Regulatory Matters

Capital and Regulatory Matters	12 Months Ended
Capital and Regulatory Matters	Dec. 31, 2022
Broker-Dealer, Net Capital Requirement, SEC Regulation [Abstract]
Capital and Regulatory Matters	Capital and Regulatory Matters Banks and bank holding companies are subject to various regulatory capital requirements administered by state and federal banking agencies. Capital adequacy guidelines and, additionally for banks, prompt corrective action regulations, involve quantitative measures of assets, liabilities, and certain off-balance-sheet items calculated under regulatory accounting practices. Capital amounts and classifications are also subject to qualitative judgments by regulators about components, risk weighting and other factors. Cullen/Frost and Frost Bank are each required to comply with applicable capital adequacy standards established by the Federal Reserve Board (the “Basel III Capital Rules”). Quantitative measures established by the Basel III Capital Rules designed to ensure capital adequacy require the maintenance of minimum amounts and ratios (set forth below) of Common Equity Tier 1 capital, Tier 1 capital and Total capital (as defined in the regulations) to risk-weighted assets (as defined), and of Tier 1 capital to adjusted quarterly average assets (as defined). Cullen/Frost’s and Frost Bank’s Common Equity Tier 1 capital includes common stock and related paid-in capital, net of treasury stock, and retained earnings. In connection with the adoption of the Basel III Capital Rules, we elected to opt-out of the requirement to include most components of accumulated other comprehensive income in Common Equity Tier 1. We also elected to delay, for a five Tier 1 capital includes Common Equity Tier 1 capital and additional Tier 1 capital. For Cullen/Frost, additional Tier 1 capital at December 31, 2022 and 2021 included $145.5 million of 4.450% non-cumulative perpetual preferred stock, the details of which is are further discussed below. Frost Bank did not have any additional Tier 1 capital beyond Common Equity Tier 1 at December 31, 2022 or 2021. Total capital includes Tier 1 capital and Tier 2 capital. Tier 2 capital for both Cullen/Frost and Frost Bank includes a permissible portion of the allowance for credit losses on securities, loans and off-balance sheet exposures. Tier 2 capital for Cullen/Frost also includes trust preferred securities that were excluded from Tier 1 capital and qualified subordinated debt. Cullen/Frost's Tier 2 capital included $120.0 million of trust preferred securities at both December 31, 2022 and 2021. Cullen/Frost's Tier 2 Capital also included $80.0 million at December 31, 2022 and $100.0 million at December 31, 2021 related to the permissible portion of our aggregate $100 million of 4.50% subordinated notes. The permissible portion of qualified subordinated notes decreases 20% per year during the final five The Common Equity Tier 1, Tier 1 and Total capital ratios are calculated by dividing the respective capital amounts by risk-weighted assets. Risk-weighted assets are calculated based on regulatory requirements and include total assets, with certain exclusions, allocated by risk weight category, and certain off-balance-sheet items, among other things. The leverage ratio is calculated by dividing Tier 1 capital by adjusted quarterly average total assets, which exclude goodwill and other intangible assets, among other things. The Basel III Capital Rules require Cullen/Frost and Frost Bank to maintain (i) a minimum ratio of Common Equity Tier 1 capital to risk-weighted assets of at least 4.5%, plus a 2.5% “capital conservation buffer” (which is added to the 4.5% Common Equity Tier 1 capital ratio, effectively resulting in a minimum ratio of Common Equity Tier 1 capital to risk-weighted assets of at least 7.0%), (ii) a minimum ratio of Tier 1 capital to risk-weighted assets of at least 6.0%, plus the capital conservation buffer (which is added to the 6.0% Tier 1 capital ratio, effectively resulting in a minimum Tier 1 capital ratio of 8.5%), (iii) a minimum ratio of Total capital (that is, Tier 1 plus Tier 2) to risk-weighted assets of at least 8.0%, plus the capital conservation buffer (which is added to the 8.0% total capital ratio, effectively resulting in a minimum total capital ratio of 10.5%) and (iv) a minimum leverage ratio of 4.0%, calculated as the ratio of Tier 1 capital to average quarterly assets. The capital conservation buffer is designed to absorb losses during periods of economic stress and, as detailed above, effectively increases the minimum required risk-weighted capital ratios. Banking institutions with a ratio of Common Equity Tier 1 capital to risk-weighted assets below the effective minimum (4.5% plus the capital conservation buffer and, if applicable, the “countercyclical capital buffer,” which is discussed below) will face constraints on dividends, equity repurchases and compensation based on the amount of the shortfall and the institution's “eligible retained income” (that is, four quarter trailing net income, net of distributions and tax effects not reflected in net income). The countercyclical capital buffer is applicable to only certain covered institutions and does not have any current applicability to Cullen/Frost or Frost Bank. As discussed in Note 1 - Significant Accounting Policies, in connection with the adoption of ASC 326, we recognized an after-tax cumulative effect reduction to retained earnings totaling $29.3 million on January 1, 2020. In February 2019, the federal bank regulatory agencies issued a final rule (the “2019 CECL Rule”) that revised certain capital regulations to account for changes to credit loss accounting under U.S. GAAP. The 2019 CECL Rule included a transition option that allows banking organizations to phase in, over a three-year period, the day-one adverse effects of CECL on their regulatory capital ratios (three-year transition option). In March 2020, the federal bank regulatory agencies issued an interim final rule that maintains the three-year transition option of the 2019 CECL Rule and also provides banking organizations that were required under U.S. GAAP (as of January 2020) to implement CECL before the end of 2020 the option to delay for two years an estimate of the effect of CECL on regulatory capital, relative to the incurred loss methodology’s effect on regulatory capital, followed by a three five five In April 2020, we began originating loans to qualified small businesses under the PPP administered by the SBA. Federal bank regulatory agencies have issued an interim final rule that permits banks to neutralize the regulatory capital effects of participating in the Paycheck Protection Program Lending Facility (the “PPP Facility”) and clarify that PPP loans have a zero percent risk weight under applicable risk-based capital rules. Specifically, a bank may exclude all PPP loans pledged as collateral to the PPP Facility from its average total consolidated assets for the purposes of calculating its leverage ratio, while PPP loans that are not pledged as collateral to the PPP Facility will be included. Our PPP loans are included in the calculation of our leverage ratio as of December 31, 2022 and 2021 as we did not utilize the PPP Facility for funding purposes. The following table presents actual and required capital ratios as of December 31, 2022 and December 31, 2021 for Cullen/Frost and Frost Bank under the Basel III Capital Rules. Capital levels required to be considered well capitalized are based upon prompt corrective action regulations, as amended to reflect the changes under the Basel III Capital Rules. Actual Minimum Capital Required to be Considered Well Capitalized (1) Capital Ratio Capital Ratio Capital Ratio 2022 Common Equity Tier 1 to Risk-Weighted Assets Cullen/Frost $ 3,751,200 12.85 % $ 2,042,876 7.00 % N/A N/A Frost Bank 3,789,056 13.00 2,040,388 7.00 $ 1,894,646 6.50 % Tier 1 Capital to Risk-Weighted Assets Cullen/Frost 3,896,652 13.35 2,480,635 8.50 1,751,036 6.00 Frost Bank 3,789,056 13.00 2,477,614 8.50 2,331,872 8.00 Total Capital to Risk-Weighted Assets Cullen/Frost 4,330,982 14.84 3,064,313 10.50 2,918,394 10.00 Frost Bank 4,023,386 13.80 3,060,583 10.50 2,914,841 10.00 Leverage Ratio Cullen/Frost 3,896,652 7.29 2,136,680 4.00 N/A N/A Frost Bank 3,789,056 7.09 2,136,316 4.00 2,670,395 5.00 2021 Common Equity Tier 1 to Risk-Weighted Assets Cullen/Frost $ 3,371,043 13.13 % $ 1,796,549 7.00 % N/A N/A Frost Bank 3,261,532 12.72 1,795,221 7.00 $ 1,666,991 6.50 % Tier 1 Capital to Risk-Weighted Assets Cullen/Frost 3,516,495 13.70 2,181,523 8.50 1,539,899 6.00 Frost Bank 3,261,532 12.72 2,179,911 8.50 2,051,681 8.00 Total Capital to Risk-Weighted Assets Cullen/Frost 3,966,244 15.45 2,694,823 10.50 2,566,498 10.00 Frost Bank 3,491,281 13.61 2,692,831 10.50 2,564,601 10.00 Leverage Ratio Cullen/Frost 3,516,495 7.34 1,917,533 4.00 N/A N/A Frost Bank 3,261,532 6.80 1,917,679 4.00 2,397,099 5.00 ____________________ (1) “Well-capitalized” minimum Common Equity Tier 1 to Risk-Weighted Assets and Leverage Ratio are not formally defined under applicable banking regulations for bank holding companies. As of December 31, 2022, capital levels for Cullen/Frost and Frost Bank exceed all capital adequacy requirements under the Basel III Capital Rules. Based on the ratios presented above, capital levels as of December 31, 2022 for Cullen/Frost and Frost Bank exceed the minimum levels necessary to be considered “well capitalized.” Cullen/Frost and Frost Bank are subject to the regulatory capital requirements administered by the Federal Reserve Board and, for Frost Bank, the Federal Deposit Insurance Corporation (“FDIC”). Regulatory authorities can initiate certain mandatory actions if Cullen/Frost or Frost Bank fail to meet the minimum capital requirements, which could have a direct material effect on our financial statements. Management believes, as of December 31, 2022, that Cullen/Frost and Frost Bank meet all capital adequacy requirements to which they are subject. Series B Preferred Stock. On November 19, 2020, we issued 150,000 shares, or $150.0 million in aggregate liquidation preference, of our 4.450% Non-Cumulative Perpetual Preferred Stock, Series B, par value $0.01 and liquidation preference $1,000 per share (“Series B Preferred Stock”). Each share of Series B Preferred Stock issued and outstanding is represented by 40 depositary shares, each representing a 1/40th ownership interest in a share of the Series B Preferred Stock (equivalent to a liquidation preference of $25 per share). Each holder of depositary shares will be entitled, in proportion to the applicable fraction of a share of Series B Preferred Stock represented by such depositary shares, to all rights and preferences of the Series B Preferred Stock represented thereby (including dividend, voting, redemption, and liquidation rights). Such rights must be exercised through the depositary. Dividends on the Series B Preferred Stock will be non-cumulative and, if declared, accrue and are payable quarterly, in arrears, at a rate of 4.450% per annum. The Series B Preferred Stock qualifies as Tier 1 capital for the purposes of the regulatory capital calculations. The net proceeds from the issuance and sale of the Series B Preferred Stock, after deducting $4.5 million of issuance costs including the underwriting discount and professional service fees, among other things, were approximately $145.5 million. The Series B Preferred Stock is perpetual and has no maturity date. We may redeem the Series B Preferred Stock at our option (i) in whole or in part, from time to time, on any dividend payment date on or after December 15, 2025 or (ii) in whole but not in part, within 90 days following certain changes in laws or regulations impacting the regulatory capital treatment of the Series B Preferred Stock, in either case, at a redemption price equal to $1,000 per share of Series B Preferred Stock (equivalent to $25 per depositary share), plus any declared and unpaid dividends for prior dividend periods and accrued but unpaid dividends (whether or not declared) for the then-current dividend period prior to but excluding the redemption date. If we redeem the Series B Preferred Stock, the depositary is expected redeem a proportionate number of depositary shares. Neither the holders of Series B Preferred Stock nor holders of depositary shares will have the right to require the redemption or repurchase of the Series B Preferred Stock or the depositary shares. Series A Preferred Stock. On February 15, 2013, we issued and sold 6,000,000 shares, or $150.0 million in aggregate liquidation preference, of our 5.375% Non-Cumulative Perpetual Preferred Stock, Series A, par value $0.01 and liquidation preference $25 per share (“Series A Preferred Stock”). On March 16, 2020, we redeemed all of the outstanding shares of our Series A Preferred Stock at a redemption price of $25 per share, or an aggregate redemption of $150.0 million. When issued, the net proceeds of the Series A Preferred Stock totaled $144.5 million after deducting $5.5 million of issuance costs including the underwriting discount and professional service fees, among other things. Upon redemption, these issuance costs were reclassified to retained earnings and reported as a reduction of net income available to common shareholders. Prior to redemption, dividends on the Series A Preferred Stock were paid quarterly, in arrears, at a rate of 5.375% per annum and the Series A Preferred Stock qualified as Tier 1 capital for the purposes of regulatory capital calculations. Stock Repurchase Plans. From time to time, our board of directors has authorized stock repurchase plans. In general, stock repurchase plans allow us to proactively manage our capital position and return excess capital to shareholders. Shares purchased under such plans also provide us with shares of common stock necessary to satisfy obligations related to stock compensation awards. On January 25, 2023, our board of directors authorized a $100.0 million stock repurchase plan, allowing us to repurchase shares of our common stock over a one In July 2019, the federal bank regulators adopted final rules (the “Capital Simplifications Rules”) that, among other things, eliminated the standalone prior approval requirement in the Basel III Capital Rules for any repurchase of common stock. In certain circumstances, Cullen/Frost’s repurchases of its common stock may be subject to a prior approval or notice requirement under other regulations, policies or supervisory expectations of the Federal Reserve Board. Any redemption or repurchase of preferred stock or subordinated debt remains subject to the prior approval of the Federal Reserve Board. In August 2022, the Inflation Reduction Act of 2022 (the “IRA”) was enacted. Among other things, the IRA imposes a new 1% excise tax on the fair market value of stock repurchased after December 31, 2022 by publicly traded U.S. corporations. With certain exceptions, the value of stock repurchased is determined net of stock issued in the year, including shares issued pursuant to compensatory arrangements. Dividend Restrictions . In the ordinary course of business, Cullen/Frost is dependent upon dividends from Frost Bank to provide funds for the payment of dividends to shareholders and to provide for other cash requirements, including to repurchase its common stock. Banking regulations may limit the amount of dividends that may be paid. Approval by regulatory authorities is required if the effect of dividends declared would cause the regulatory capital of Frost Bank to fall below specified minimum levels. Approval is also required if dividends declared exceed the net profits for that year combined with the retained net profits for the preceding two years. Under the foregoing dividend restrictions and while maintaining its “well capitalized” status, at December 31, 2022, Frost Bank could pay aggregate dividends of up to $813.6 million to Cullen/Frost without prior regulatory approval. Under the terms of the junior subordinated deferrable interest debentures that Cullen/Frost has issued to Cullen/Frost Capital Trust II, Cullen/Frost has the right at any time during the term of the debentures to defer the payment of interest at any time or from time to time for an extension period not exceeding 20 consecutive quarterly periods with respect to each extension period. In the event that we have elected to defer interest on the debentures, we may not, with certain exceptions, declare or pay any dividends or distributions on our capital stock or purchase or acquire any of our capital stock. Under the terms of the Series B Preferred Stock, in the event that we do not declare and pay dividends on the Series B Preferred Stock for the most recent dividend period, we may not, with certain exceptions, declare or pay dividends on, or purchase, redeem or otherwise acquire, shares of our common stock or any of our securities that rank junior to the Series B Preferred Stock.

Earnings Per Common Share

Earnings Per Common Share	12 Months Ended
Earnings Per Common Share	Dec. 31, 2022
Earnings Per Share [Abstract]
Earnings Per Common Share	Earnings Per Common Share Earnings Per Common Share . Earnings per common share is computed using the two-class method. Basic earnings per common share is computed by dividing net earnings allocated to common stock by the weighted-average number of common shares outstanding during the applicable period, excluding outstanding participating securities. Participating securities include non-vested stock awards/stock units, deferred stock units and performance stock units (during the performance period), though no actual shares of common stock related to any type of stock unit have been issued. Non-vested stock awards/stock units and deferred stock units are considered participating securities because holders of these securities receive non-forfeitable dividends at the same rate as holders of our common stock. Holders of performance stock units receive dividend equivalent payments for dividends paid during the performance period at the vesting date of the award based upon the number of units that ultimately vest. Diluted earnings per common share is computed using the weighted-average number of shares determined for the basic earnings per common share computation plus the dilutive effect of stock compensation using the treasury stock method. The following table presents a reconciliation of net income available to common shareholders, net earnings allocated to common stock and the number of shares used in the calculation of basic and diluted earnings per common share. 2022 2021 2020 Net Income $ 579,150 $ 443,079 $ 331,151 Less: Preferred stock dividends 6,675 7,157 2,016 Redemption of preferred stock — — 5,514 Net income available to common shareholders 572,475 435,922 323,621 Less: Earnings allocated to participating securities 5,210 3,881 3,136 Net earnings allocated to common stock $ 567,265 $ 432,041 $ 320,485 Distributed earnings allocated to common stock $ 207,924 $ 187,202 $ 178,863 Undistributed earnings allocated to common stock 359,341 244,839 141,622 Net earnings allocated to common stock $ 567,265 $ 432,041 $ 320,485 Weighted-average shares outstanding for basic earnings per common share 64,156,870 63,612,658 62,727,053 Dilutive effect of stock compensation 363,648 489,462 276,784 Weighted-average shares outstanding for diluted earnings per common share 64,520,518 64,102,120 63,003,837

Employee Benefit Plans

Employee Benefit Plans	12 Months Ended
Employee Benefit Plans	Dec. 31, 2022
Retirement Benefits [Abstract]
Employee Benefit Plans	Employee Benefit Plans Retirement Plans Retirement Plan and Restoration Plan. We maintain a non-contributory defined benefit plan (the “Retirement Plan”) that was frozen as of December 31, 2001. The plan provides pension and death benefits to substantially all employees who were at least 21 years of age and had completed at least one year of service prior to December 31, 2001. Defined benefits are provided based on an employee’s final average compensation and years of service at the time the plan was frozen and age at retirement. The freezing of the plan provides that future salary increases will not be considered. Our funding policy is to contribute yearly, at least the amount necessary to satisfy the funding standards of the Employee Retirement Income Security Act (“ERISA”). Our Restoration of Retirement Income Plan (the “Restoration Plan”) provides benefits for eligible employees that are in excess of the limits under Section 415 of the Internal Revenue Code of 1986, as amended, that apply to the Retirement Plan. The Restoration Plan is designed to comply with the requirements of ERISA. The entire cost of the plan, which was also frozen as of December 31, 2001, is supported by our contributions. We use a December 31 measurement date for our defined benefit plans. Combined activity in our defined benefit pension plans was as follows: 2022 2021 2020 Change in plan assets: Fair value of plan assets at beginning of year $ 197,747 $ 182,088 $ 174,173 Actual return on plan assets (26,108) 24,908 16,599 Employer contributions 1,114 1,236 1,201 Benefits paid (10,930) (10,485) (9,885) Fair value of plan assets at end of year 161,823 197,747 182,088 Change in benefit obligation: Benefit obligation at beginning of year 185,925 197,593 186,641 Interest cost 4,017 3,341 5,010 Actuarial (gain) loss (35,068) (4,524) 15,827 Benefits paid (10,930) (10,485) (9,885) Benefit obligation at end of year 143,944 185,925 197,593 Funded status of the plan at end of year and accrued benefit (liability) recognized $ 17,879 $ 11,822 $ (15,505) Accumulated benefit obligation at end of year $ 143,944 $ 185,925 $ 197,593 Certain disaggregated information related to our defined benefit pension plans as of year-end was as follows: Retirement Plan Restoration Plan 2022 2021 2022 2021 Projected benefit obligation $ 131,648 $ 170,389 $ 12,296 $ 15,536 Accumulated benefit obligation 131,648 170,389 12,296 15,536 Fair value of plan assets 161,823 197,747 — — Funded status of the plan at end of year and accrued benefit (liability) recognized 30,175 27,358 (12,296) (15,536) The components of the combined net periodic cost (benefit) for our defined benefit pension plans are presented in the table below. 2022 2021 2020 Expected return on plan assets, net of expenses $ (13,966) $ (12,839) $ (12,289) Interest cost on projected benefit obligation 4,017 3,341 5,010 Net amortization and deferral 2,964 6,116 5,319 Net periodic expense (benefit) $ (6,985) $ (3,382) $ (1,960) Amounts related to our defined benefit pension plans recognized as a component of other comprehensive income were as follows: 2022 2021 2020 Net actuarial gain (loss) $ (2,041) $ 22,709 $ (6,199) Deferred tax (expense) benefit 429 (4,769) 1,302 Other comprehensive income (loss), net of tax $ (1,612) $ 17,940 $ (4,897) Amounts recognized as a component of accumulated other comprehensive loss as of year-end that have not been recognized as a component of the combined net periodic benefit cost of our defined benefit pension plans are presented in the following table. 2022 2021 Net actuarial loss $ (43,675) $ (41,634) Deferred tax benefit 9,172 8,743 Amounts included in accumulated other comprehensive income/loss, net of tax (34,503) (32,891) The weighted-average assumptions used to determine the benefit obligations as of the end of the years indicated and the net periodic benefit cost for the years indicated are presented in the table below. Because the plans were frozen, increases in compensation are not considered after 2001. 2022 2021 2020 Benefit obligations: Discount rate 5.14 % 2.79 % 2.43 % Net periodic benefit cost: Discount rate 2.79 % 2.43 % 3.20 % Expected return on plan assets 7.25 7.25 7.25 Management uses an asset allocation optimization model to analyze the potential risks and rewards associated with various asset allocation strategies on a quarterly basis. As of December 31, 2022, management’s investment objective for our defined benefit plans is to achieve long-term growth. This strategy provides for a target asset allocation of approximately 64% invested in equity securities, approximately 31% invested in fixed income debt securities with any remainder invested in cash or short-term cash equivalents. The asset allocation optimization process provides portfolio allocations which best represent the potential risk associated with a given asset allocation over a full market cycle. This is used to help management determine an appropriate mix of assets in order to achieve the plan's long term investment goals. The plan assets are reviewed annually to determine if the obligations can be met with the current investment mix and funding strategy. The major categories of assets in our Retirement Plan as of year-end are presented in the following table. Assets are segregated by the level of the valuation inputs within the fair value hierarchy established by ASC Topic 820 “Fair Value Measurements and Disclosures,” utilized to measure fair value (see Note 17 - Fair Value Measurements). Our Restoration Plan is unfunded. 2022 2021 Level 1: Mutual funds $ 154,391 $ 195,452 Cash and cash equivalents 7,432 2,295 Total fair value of plan assets $ 161,823 $ 197,747 Mutual funds include various equity, fixed-income and blended funds with varying investment strategies. Approximately 67% of mutual fund investments consist of equity investments as of December 31, 2022. The investment objective of equity funds is long-term capital appreciation with current income. The remaining mutual fund investments consist of U.S. fixed-income securities, including investment-grade U.S. Treasury securities, U.S. government agency securities and mortgage-backed securities, corporate bonds and notes and collateralized mortgage obligations. The investment objective of fixed-income funds is to maximize investment return while preserving investment principal. Our investment strategies prohibit selling assets short and the use of derivatives. Additionally, our defined benefit plans do not directly invest in real estate, commodities, or private investments. The asset allocation optimization model is used to estimate the expected long-term rate of return for a given asset allocation strategy. Expectations of returns for each asset class are based on comprehensive reviews of historical data and economic/financial market theory. During periods with volatile interest rates and equity security prices, the model may call for changes in the allocation of plan investments to achieve desired returns. Management assumed a long-term rate of return of 7.25% in the determination of the net periodic benefit cost for 2022. The expected long-term rate of return on assets was selected from within the reasonable range of rates determined by historical real returns, net of inflation, for the asset classes covered by the plan’s investment policy and projections of inflation over the long-term period during which benefits are payable to plan participants. As of December 31, 2022, expected future benefit payments related to our defined benefit plans were as follows: 2023 $ 11,864 2024 12,128 2025 12,059 2026 11,995 2027 11,848 2028 through 2032 55,245 $ 115,139 We expect to contribute $1.2 million to the defined benefit plans during 2023. Savings Plans 401(k) Stock Purchase Plan and Other Plans. We maintain a 401(k) stock purchase plan that permits each participant to make before-tax contributions in an amount not less than 2% and not exceeding 50% of eligible compensation and subject to dollar limits from Internal Revenue Service regulations. We match 100% of the employee’s contributions to the plan based on the amount of each participant’s contributions up to a maximum of 6% of eligible compensation. Eligible employees must complete 30 days of service in order to enroll and vest in our matching contributions immediately. Our matching contribution is initially invested in the common stock of Cullen/Frost. Employees may immediately reallocate our matching portion, as well as invest their individual contribution, to any of a variety of investment alternatives offered under the 401(k) Plan. We may also make discretionary profit sharing contributions to eligible participants. All profit sharing contributions to the plan are made at our discretion and may be made without regard to current or accumulated profits. Contributions are generally allocated to eligible participants uniformly, based upon compensation, age and/or other factors. Plan participants self-direct the investment of allocated contributions by choosing from a menu of investment options. Profit sharing contributions are subject to withdrawal restrictions and participants vest in their allocated contributions after three years of service. Expense related to the plan totaled $28.0 million in 2022, $23.8 million in 2021 and $17.9 million in 2020. We maintain a thrift incentive stock purchase plan and a separate non-qualified profit sharing plan to offer certain employees, whose participation in the 401(k) plan is limited, an alternative means of receiving comparable benefits. Expense related to these plans was not significant during 2022, 2021 and 2020. Stock Compensation Plans We have three active stock compensation plans (the 2005 Omnibus Incentive Plan, the 2007 Outside Directors Incentive Plan and the 2015 Omnibus Incentive Plan). All of the plans have been approved by our shareholders. During 2015, the 2015 Omnibus Incentive Plan (“2015 Plan”) was established to replace both the 2005 Omnibus Incentive Plan (“2005 Plan”) and the 2007 Outside Directors Incentive Plan (the “2007 Directors Plan”). All remaining shares authorized for grant under the superseded 2005 Plan and 2007 Directors Plan were transferred to the 2015 Plan. Our stock compensation plans were established to (i) motivate superior performance by means of performance-related incentives, (ii) encourage and provide for the acquisition of an ownership interest in our company by employees and non-employee directors and (iii) enable us to attract and retain qualified and competent persons as employees and to serve as members of our board of directors. Under the 2015 Plan, we may grant, among other things, nonqualified stock options, incentive stock options, stock awards, stock appreciation rights, restricted stock units, performance share units or any combination thereof to certain employees and non-employee directors. Any of the authorized shares may be used for any type of award allowable under the Plan. The Compensation and Benefits Committee (“Committee”) of our Board of Directors has sole authority to (i) establish the awards to be issued, (ii) select the employees and non-employee directors to receive awards, and (iii) approve the terms and conditions of each award contract. Each award under the stock plans is evidenced by an award agreement that specifies the award price, the duration of the award, the number of shares to which the award pertains, and such other provisions as the Committee determines. For stock options, the option price for each grant is at least equal to the fair market value of a share of Cullen/Frost’s common stock on the date of grant. Options granted expire at such time as the Committee determines at the date of grant and in no event does the exercise period exceed a maximum of ten years. As defined in the plans, outstanding awards may immediately vest upon a change-in-control of Cullen/Frost and, in the case of awards granted under the 2015 Plan, subsequent termination resulting from the change in control. A combined summary of activity in our active stock plans is presented in the table. Performance stock units outstanding are presented assuming attainment of the maximum payout rate as set forth by the performance criteria. The target award level for performance stock units granted in 2022, 2021 and 2020 was 35,015, 30,723 and 48,409, respectively. As of December 31, 2022, there were 505,456 shares remaining available for grant for future awards. Director Deferred Non-Vested Stock Performance Stock Units Outstanding Stock Options Number of Units Weighted- Number Weighted- Number of Units Weighted- Number Weighted- January 1, 2020 55,370 $ 74.76 440,647 $ 90.22 177,288 $ 83.48 1,980,866 $ 64.60 Granted 10,428 73.84 151,038 66.79 72,618 57.89 — — Exercised/vested (12,938) 71.09 (117,990) 76.07 (41,755) 69.70 (235,880) 53.23 Forfeited/expired — — (3,336) 91.07 (6,894) 81.33 (5,427) 75.74 December 31, 2020 52,860 75.47 470,359 86.24 201,257 77.18 1,739,559 66.11 Granted 5,940 117.90 95,258 130.36 46,086 121.46 — — Exercised/vested (2,499) 92.03 (88,250) 98.90 (35,131) 92.27 (861,878) 63.14 Forfeited/expired — — (28,030) 87.08 (9,752) 75.70 — — December 31, 2021 56,301 79.21 449,337 93.05 202,460 84.71 877,681 69.02 Granted 5,382 133.67 119,176 142.56 52,527 133.40 — — Exercised/vested (16,022) 74.89 (97,154) 94.81 (25,180) 87.18 (261,454) 63.72 Forfeited/expired — — (6,040) 93.28 (16,058) 87.18 — — December 31, 2022 45,661 87.15 465,319 105.36 213,749 96.20 616,227 71.27 Options awarded to employees generally have a ten four three four Performance stock units represent shares potentially issuable in the future. For performance stock units granted in 2022 and 2021, issuance is based upon the measure of our achievement of growth in adjusted net revenue, averaged over the three-year performance period, compared to the 2022 and 2021 base-year amounts, respectively. Adjusted net revenue for each three-year performance period is calculated as the sum of taxable-equivalent net interest income (excluding the effects of PPP lending) and non-interest income, reduced by non-interest expense (excluding the effects of PPP lending) and net charge-offs. The 2022 and 2021 base-year adjusted net revenue amounts of approximately $713.8 million and $415.9 million, respectively, were calculated as the sum of taxable-equivalent net interest income (excluding the effects of PPP lending) and non-interest income, reduced by non-interest expense (excluding the effects of PPP lending) and the product of average total loans (excluding PPP loans) and 0.30%. The ultimate number of shares issuable under each performance award is the product of the award target and the award payout percentage for the given level of achievement. The level of achievement is measured as the amount by which adjusted net revenue, averaged over a three-year performance period, exceeds the 2022 and 2021 base-year amounts, as applicable, stated as an average growth percentage. The award payout percentages by level of achievement for both the 2022 and 2021 awards are as follows: (i) less than 13% average growth pays out at 0% of target, (ii) 13% average growth pays out at 50% of target, (iii) 19% average growth pays out at 100% of target and (iv) 25% average growth or more pays out at 150% of target. Achievement between the aforementioned average growth percentages will result in an award payout percentage determined based on straight-line interpolation between the percentages. For performance stock units granted prior to 2021, issuance is based upon the measure of our achievement of relative return on assets over a three-year performance period compared to an identified peer group's achievement of relative return on assets over the same three-year performance period. The ultimate number of shares issuable under each performance award is the product of the award target and the award payout percentage for the given level of achievement. The level of achievement is measured as the percentile rank of relative return on assets among the peer group. The award payout percentages by level of achievement are as follows: (i) less than 25th percentile pays out at 0% of target, (ii) 25th percentile pays out at 50% of target, (iii) 50th percentile pays out at 100% of target and (iv) 75th percentile or more pays out at 150% of target. Achievement between the aforementioned percentiles will result in an award payout percentage determined based on straight-line interpolation between the percentiles. Performance stock units are eligible to receive equivalent dividend payments as such dividends are declared on our common stock during the performance period. Equivalent dividend payments are based upon the ultimate number of shares issued under each performance award and are deferred until such time that the units vest and shares are issued. Other information regarding options outstanding and exercisable as of December 31, 2022 is as follows: Options Outstanding Options Exercisable Range of Number Weighted- Weighted- Number Weighted- $ 65.01 to $ 70.00 277,131 $ 65.11 2.82 277,131 $ 65.11 70.01 to 75.00 117,686 71.39 0.83 117,686 71.39 75.01 to 80.00 221,410 78.92 1.83 221,410 78.92 Total 616,227 71.27 2.08 616,227 71.27 Total intrinsic value $ 38,470 $ 38,470 Shares issued in connection with stock compensation awards are issued from available treasury shares. If no treasury shares are available, new shares are issued from available authorized shares. Shares issued in connection with stock compensation awards along with other related information were as follows: 2022 2021 2020 New shares issued from available authorized shares 118,389 — — Shares issued from available treasury stock 281,421 987,758 408,563 Total 399,810 987,758 408,563 Proceeds from stock option exercises $ 16,659 $ 54,417 $ 12,557 Intrinsic value of stock options exercised 19,616 43,904 5,365 Fair value of stock awards/units vested 19,308 15,751 12,773 Stock-based Compensation Expense. Stock-based compensation expense is recognized ratably over the requisite service period for all awards. For most stock option awards, the service period generally matches the vesting period. For stock options granted to certain executive officers and for non-vested stock units granted to all participants, the service period does not extend past the date the participant reaches 65 years of age. Deferred stock units granted to non-employee directors generally have immediate vesting and the related expense is fully recognized on the date of grant. For performance stock units, the service period generally matches the three-year performance period specified by the award, however, the service period does not extend past the date the participant reaches 65 years of age. Expense recognized each period is dependent upon our estimate of the number of shares that will ultimately be issued. Stock-based compensation expense and the related income tax benefit is presented in the following table. The service period for performance stock units granted each year begins on January 1 of the following year. 2022 2021 2020 Non-vested stock awards/stock units $ 13,162 $ 9,977 $ 10,240 Deferred stock-units 720 700 770 Performance stock units 4,440 2,076 2,908 Total $ 18,322 $ 12,753 $ 13,918 Income tax benefit $ 2,969 $ 1,713 $ 2,142 Unrecognized stock-based compensation expense and the weighted-average period over which the expense is expected to be recognized at December 31, 2022 is presented in the table below. Unrecognized stock-based compensation expense related to performance stock units is presented assuming attainment of the maximum payout rate as set forth by the performance criteria. Unrecognized Expense Weighted-Average Number of Years for Expense Recognition Non-vested stock awards/stock units $ 21,770 2.15 Performance stock units 11,078 1.80 Total $ 32,848 Valuation of Stock-Based Compensation . For the purposes of recognizing stock-based compensation expense, the fair value of non-vested stock awards/stock units and deferred stock units is generally the market price of the stock on the measurement date, which, for us, is the date of the award. The fair value of performance stock units is determined in a similar manner except that the market price of the stock on the measurement date is discounted by the present value of the dividends expected to be paid on our common stock during the service period of the award because dividend equivalent payments on performance stock units are deferred until such time that the units vest and shares are issued. In applying this discount to the market price of our stock on the measurement date, we assumed we would pay a flat quarterly dividend during the service period equal to our most recent dividend payment, which was $0.87, $0.75 and $0.72 in 2022, 2021 and 2020, respectively, discounted at a weighted-average risk-free rate of 4.45%, 0.77% and 0.19% in 2022, 2021 and 2020, respectively.

Other Non-Interest Income and E

Other Non-Interest Income and Expense	12 Months Ended
Other Non-Interest Income and Expense	Dec. 31, 2022
Other Income and Expenses [Abstract]
Other Non-Interest Income and Expense	Other Non-Interest Income and Expense Other non-interest income and expense totals are presented in the following table. Components of these totals exceeding 1% of the aggregate of total net interest income and total non-interest income for any of the years presented are stated separately. 2022 2021 2020 Other non-interest income: Other $ 45,217 $ 48,528 $ 47,712 Total $ 45,217 $ 48,528 $ 47,712 Other non-interest expense: Professional services $ 40,908 $ 34,747 $ 37,253 Advertising, promotions and public relations 39,994 34,539 34,390 Other 113,319 102,171 94,667 Total $ 194,221 $ 171,457 $ 166,310 In the ordinary course of business, we transact with certain directors and/or their affiliates. Payments for services provided totaled $545 thousand in 2022, $257 thousand in 2021 and $551 thousand in 2020.

Income Taxes

Income Taxes	12 Months Ended
Income Taxes	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Income tax expense was as follows: 2022 2021 2020 Current income tax expense $ 94,595 $ 38,675 $ 36,002 Deferred income tax expense (benefit) (4,918) 7,784 (15,832) Income tax expense, as reported $ 89,677 $ 46,459 $ 20,170 Effective tax rate 13.4 % 9.5 % 5.7 % A reconciliation between reported income tax expense and the amounts computed by applying the U.S. federal statutory income tax rate of 21% to income before income taxes is presented in the following table. 2022 2021 2020 Income tax expense computed at the statutory rate $ 140,454 $ 102,803 $ 73,777 Effect of tax-exempt interest (50,602) (50,740) (51,624) Net tax benefit from stock-based compensation (4,602) (7,877) (852) Tax benefit on dividends paid in our 401k plan (1,854) (1,764) (1,851) Bank owned life insurance income (440) (517) (783) Non-deductible FDIC premiums 3,277 2,629 1,790 Non-deductible compensation 2,250 1,773 1,123 Non-deductible meals and entertainment 683 625 786 Asset contribution to a charitable trust — — (2,556) Tax basis adjustment of premises and equipment — (1,026) — Other 511 553 360 Income tax expense, as reported $ 89,677 $ 46,459 $ 20,170 There were no unrecognized tax benefits during any of the reported periods. Interest and/or penalties related to income taxes are reported as a component of income tax expense. Such amounts were not significant during the reported periods. Year-end deferred taxes are presented in the table below. Deferred taxes are based on the U.S. statutory federal income tax rate of 21%. 2022 2021 Deferred tax assets: Lease liabilities under operating leases $ 67,608 $ 65,815 Net unrealized loss on securities available for sale and transferred securities 349,237 — Allowance for credit losses 60,137 62,819 Net actuarial loss on defined benefit post-retirement benefit plans 9,172 8,743 Stock-based compensation 6,622 6,989 Bonus accrual 11,204 7,506 Deferred loan and lease origination fees 3,675 3,118 Other 6,109 3,834 Total gross deferred tax assets 513,764 158,824 Deferred tax liabilities: Net unrealized gain on securities available for sale and transferred securities — (101,067) Right-of-use assets under operating leases (60,651) (59,415) Premises and equipment (45,647) (49,645) Intangible assets (17,732) (16,595) Defined benefit post-retirement benefit plans (12,730) (11,027) Other (2,601) (2,323) Total gross deferred tax liabilities (139,361) (240,072) Net deferred tax asset (liability) $ 374,403 $ (81,248) No valuation allowance for deferred tax assets was recorded at December 31, 2022 and 2021 as management believes it is more likely than not that all of the deferred tax assets will be realized against deferred tax liabilities and projected future taxable income. There were no unrecognized tax benefits during any of the reported periods. We file income tax returns in the U.S. federal jurisdiction. We are no longer subject to U.S. federal income tax examinations by tax authorities for years before 2019.

Other Comprehensive Income (Los

Other Comprehensive Income (Loss)	12 Months Ended
Other Comprehensive Income (Loss)	Dec. 31, 2022
Equity [Abstract]
Other Comprehensive Income (Loss)	Other Comprehensive Income (Loss) The tax effects allocated to each component of other comprehensive income (loss) were as follows: Before Tax Tax Expense, Net of Tax 2022 Securities available for sale and transferred securities: Change in net unrealized gain/loss during the period $ (2,143,567) $ (450,149) $ (1,693,418) Change in net unrealized gain on securities transferred to held to maturity (737) (155) (582) Reclassification adjustment for net (gains) losses included in net income — — — Total securities available for sale and transferred securities (2,144,304) (450,304) (1,694,000) Defined-benefit post-retirement benefit plans: Change in the net actuarial gain/loss (5,005) (1,051) (3,954) Reclassification adjustment for net amortization of actuarial gain/loss included in net income as a component of net periodic cost (benefit) 2,964 622 2,342 Total defined-benefit post-retirement benefit plans (2,041) (429) (1,612) Total other comprehensive income (loss) $ (2,146,345) $ (450,733) $ (1,695,612) 2021 Securities available for sale and transferred securities: Change in net unrealized gain/loss during the period $ (231,355) $ (48,585) $ (182,770) Change in net unrealized gain on securities transferred to held to maturity (971) (204) (767) Reclassification adjustment for net (gains) losses included in net income (69) (14) (55) Total securities available for sale and transferred securities (232,395) (48,803) (183,592) Defined-benefit post-retirement benefit plans: Change in the net actuarial gain/loss 16,593 3,485 13,108 Reclassification adjustment for net amortization of actuarial gain/loss included in net income as a component of net periodic cost (benefit) 6,116 1,284 4,832 Total defined-benefit post-retirement benefit plans 22,709 4,769 17,940 Total other comprehensive income (loss) $ (209,686) $ (44,034) $ (165,652) 2020 Securities available for sale and transferred securities: Change in net unrealized gain/loss during the period $ 427,331 $ 89,741 $ 337,590 Change in net unrealized gain on securities transferred to held to maturity (1,256) (264) (992) Reclassification adjustment for net (gains) losses included in net income (108,989) (22,888) (86,101) Total securities available for sale and transferred securities 317,086 66,589 250,497 Defined-benefit post-retirement benefit plans: Change in the net actuarial gain/loss (11,518) (2,419) (9,099) Reclassification adjustment for net amortization of actuarial gain/loss included in net income as a component of net periodic cost (benefit) 5,319 1,117 4,202 Total defined-benefit post-retirement benefit plans (6,199) (1,302) (4,897) Total other comprehensive income (loss) $ 310,887 $ 65,287 $ 245,600 Activity in accumulated other comprehensive income, net of tax, was as follows: Securities Defined Accumulated Balance January 1, 2022 $ 380,209 $ (32,891) $ 347,318 Other comprehensive income (loss) before reclassification (1,694,000) (3,954) (1,697,954) Reclassification of amounts included in net income — 2,342 2,342 Net other comprehensive income (loss) during period (1,694,000) (1,612) (1,695,612) Balance December 31, 2022 $ (1,313,791) $ (34,503) $ (1,348,294) Balance January 1, 2021 $ 563,801 $ (50,831) $ 512,970 Other comprehensive income (loss) before reclassification (183,537) 13,108 (170,429) Reclassification of amounts included in net income (55) 4,832 4,777 Net other comprehensive income (loss) during period (183,592) 17,940 (165,652) Balance December 31, 2021 $ 380,209 $ (32,891) $ 347,318 Balance January 1, 2020 $ 313,304 $ (45,934) $ 267,370 Other comprehensive income (loss) before reclassification 336,598 (9,099) 327,499 Reclassification of amounts included in net income (86,101) 4,202 (81,899) Net other comprehensive income (loss) during period 250,497 (4,897) 245,600 Balance December 31, 2020 $ 563,801 $ (50,831) $ 512,970

Derivative Financial Instrument

Derivative Financial Instruments	12 Months Ended
Derivative Financial Instruments	Dec. 31, 2022
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	Derivative Financial Instruments The fair value of derivative positions outstanding is included in accrued interest receivable and other assets and accrued interest payable and other liabilities in the accompanying consolidated balance sheets and in the net change in each of these financial statement line items in the accompanying consolidated statements of cash flows. Interest Rate Derivatives. We utilize interest rate swaps, caps and floors to mitigate exposure to interest rate risk and to facilitate the needs of our customers. Our objectives for utilizing these derivative instruments are described below: We have entered into certain interest rate swap contracts that are matched to specific fixed-rate commercial loans or leases that we have entered into with our customers. These contracts have been designated as hedging instruments to hedge the risk of changes in the fair value of the underlying commercial loan/lease due to changes in interest rates. The related contracts are structured so that the notional amounts reduce over time to generally match the expected amortization of the underlying loan/lease. We have entered into certain interest rate swap, cap and floor contracts that are not designated as hedging instruments. These derivative contracts relate to transactions in which we enter into an interest rate swap, cap and/or floor with a customer while at the same time entering into an offsetting interest rate swap, cap and/or floor with a third-party financial institution. In connection with each swap transaction, we agree to pay interest to the customer on a notional amount at a variable interest rate and receive interest from the customer on a similar notional amount at a fixed interest rate. At the same time, we agree to pay a third-party financial institution the same fixed interest rate on the same notional amount and receive the same variable interest rate on the same notional amount. The transaction allows our customer to effectively convert a variable rate loan to a fixed rate. Because we act as an intermediary for our customer, changes in the fair value of the underlying derivative contracts for the most part offset each other and do not significantly impact our results of operations. The notional amounts and estimated fair values of interest rate derivative contracts outstanding at December 31, 2022 and 2021 are presented in the following table. The fair values of interest rate derivative contracts are estimated utilizing internal valuation methods with observable market data inputs, or as determined by the Chicago Mercantile Exchange (“CME”) for centrally cleared derivative contracts. CME rules legally characterize variation margin payments for centrally cleared derivatives as settlements of the derivatives' exposure rather than collateral. As a result, the variation margin payment and the related derivative instruments are considered a single unit of account for accounting and financial reporting purposes. Variation margin, as determined by the CME, is settled daily. As a result, derivative contracts that clear through the CME have an estimated fair value of zero as of December 31, 2022 and 2021. December 31, 2022 December 31, 2021 Notional Estimated Notional Estimated Derivatives designated as hedges of fair value: Financial institution counterparties: Loan/lease interest rate swaps - assets $ 1,614 $ 19 $ — $ — Loan/lease interest rate swaps - liabilities — — 2,426 (34) Non-hedging interest rate derivatives: Financial institution counterparties: Loan/lease interest rate swaps - assets 1,165,812 70,416 247,592 1,207 Loan/lease interest rate swaps - liabilities 78,798 (1,102) 928,756 (19,142) Loan/lease interest rate caps - assets 246,442 15,256 270,431 3,239 Customer counterparties: Loan/lease interest rate swaps - assets 53,570 1,102 928,756 39,864 Loan/lease interest rate swaps - liabilities 1,175,563 (79,175) 247,592 (2,846) Loan/lease interest rate caps - liabilities 246,442 (15,256) 270,431 (3,239) The weighted-average rates paid and received for interest rate swaps outstanding at December 31, 2022 were as follows: Weighted-Average Interest Interest Interest rate swaps: Fair value hedge loan/lease interest rate swaps 1.58 % 4.12 % Non-hedging interest rate swaps - financial institution counterparties 3.73 5.29 Non-hedging interest rate swaps - customer counterparties 5.28 3.72 The weighted-average strike rate for outstanding interest rate caps was 3.26% at December 31, 2022. Commodity Derivatives. We enter into commodity swaps and option contracts that are not designated as hedging instruments primarily to accommodate the business needs of our customers. Upon the origination of a commodity swap or option contract with a customer, we simultaneously enter into an offsetting contract with a third-party financial institution to mitigate the exposure to fluctuations in commodity prices. The notional amounts and estimated fair values of non-hedging commodity swap and option derivative positions outstanding are presented in the following table. We obtain dealer quotations and use internal valuation methods with observable market data inputs to value our commodity derivative positions. December 31, 2022 December 31, 2021 Notional Notional Estimated Notional Estimated Financial institution counterparties: Oil - assets Barrels 4,024 $ 27,082 4,809 $ 14,721 Oil - liabilities Barrels 6,068 (53,579) 7,032 (73,594) Natural gas - assets MMBTUs 16,539 6,220 15,947 4,143 Natural gas - liabilities MMBTUs 15,682 (19,138) 29,446 (21,249) Customer counterparties: Oil - assets Barrels 6,068 54,219 7,046 74,437 Oil - liabilities Barrels 4,024 (26,551) 4,796 (14,294) Natural gas - assets MMBTUs 15,682 19,164 29,446 21,456 Natural gas - liabilities MMBTUs 16,539 (6,124) 15,947 (4,124) Foreign Currency Derivatives . We enter into foreign currency forward and option contracts that are not designated as hedging instruments primarily to accommodate the business needs of our customers. Upon the origination of a foreign currency denominated transaction with a customer, we simultaneously enter into an offsetting contract with a third-party financial institution to negate the exposure to fluctuations in foreign currency exchange rates. We also utilize foreign currency forward contracts that are not designated as hedging instruments to mitigate the economic effect of fluctuations in foreign currency exchange rates on foreign currency holdings and certain short-term, non-U.S. dollar denominated loans. The notional amounts and fair values of open foreign currency forward contracts were as follows: December 31, 2022 December 31, 2021 Notional Notional Estimated Notional Estimated Financial institution counterparties: Forward/option contracts - assets EUR 875 $ 1 1,900 $ 29 Forward/option contracts - assets CAD — — 658 — Forward/option contracts - liabilities EUR 875 (10) — — Customer counterparties: Forward/option contracts - assets EUR 875 10 — — Forward/option contracts - assets CAD — — 658 4 Forward/option contracts - liabilities EUR 875 (1) 1,900 (55) Gains, Losses and Derivative Cash Flows . For fair value hedges, the changes in the fair value of both the derivative hedging instrument and the hedged item are included in other non-interest income or other non-interest expense. The extent that such changes in fair value do not offset represents hedge ineffectiveness. Net cash flows from interest rate swaps on commercial loans/leases designated as hedging instruments in effective hedges of fair value are included in interest income on loans. For non-hedging derivative instruments, gains and losses due to changes in fair value and all cash flows are included in other non-interest income and other non-interest expense. Amounts included in the consolidated statements of income related to interest rate derivatives designated as hedges of fair value were as follows: 2022 2021 2020 Commercial loan/lease interest rate swaps: Amount of gain (loss) included in interest income on loans $ (7) $ (91) $ (111) Amount of (gain) loss included in other non-interest expense 6 10 9 As stated above, we enter into non-hedge related derivative positions primarily to accommodate the business needs of our customers. Upon the origination of a derivative contract with a customer, we simultaneously enter into an offsetting derivative contract with a third-party financial institution. We recognize immediate income based upon the difference in the bid/ask spread of the underlying transactions with our customers and the third party. Because we act only as an intermediary for our customer, subsequent changes in the fair value of the underlying derivative contracts for the most part offset each other and do not significantly impact our results of operations. Amounts included in the consolidated statements of income related to non-hedging interest rate, commodity, foreign currency and other derivative instruments are presented in the table below. 2022 2021 2020 Non-hedging interest rate derivatives: Other non-interest income $ 1,742 $ 4,285 $ 3,413 Other non-interest expense — (1) 1 Non-hedging commodity derivatives: Other non-interest income 2,297 4,052 1,768 Non-hedging foreign currency derivatives: Other non-interest income 63 39 28 Non-hedging other derivatives: Other non-interest income — — 5,992 During 2020, we sold certain non-hedge related, short-term put options on U.S. Treasury securities and realized gains totaling approximately $6.0 million in connection with the sales. The put options expired without being exercised. These gains are included in the table above as a component of non-hedging other derivatives. Counterparty Credit Risk. Derivative contracts involve the risk of dealing with both bank customers and institutional derivative counterparties and their ability to meet contractual terms. Institutional counterparties must have an investment grade credit rating and be approved by our Asset/Liability Management Committee. Our credit exposure on derivative contracts is limited to the net favorable value of all contracts by each counterparty. Credit exposure may be reduced by the amount of collateral pledged by the counterparty. There are no credit-risk-related contingent features associated with any of our derivative contracts. Certain derivative contracts with upstream financial institution counterparties may be terminated with respect to a party in the transaction, if such party does not have at least a minimum level rating assigned to either its senior unsecured long-term debt or its deposit obligations by certain third-party rating agencies. Our credit exposure relating to interest rate swaps, commodity swaps/options and foreign currency forward contracts with bank customers was approximately $43.6 million at December 31, 2022. This credit exposure is partly mitigated as transactions with customers are generally secured by the collateral, if any, securing the underlying transaction being hedged. Our credit exposure, net of collateral pledged, relating to interest rate swaps, commodity swaps/options and foreign currency forward contracts with upstream financial institution counterparties was approximately $2.9 million at December 31, 2022. This amount was primarily related to excess collateral we posted to counterparties. Collateral levels for upstream financial institution counterparties are monitored and adjusted as necessary. See Note 16 – Balance Sheet Offsetting and Repurchase Agreements for additional information regarding our credit exposure with upstream financial institution counterparties. At December 31, 2022, the aggregate fair value of securities we posted as collateral related to derivative contracts totaled $8.5 million. We also had $3.2 million in cash collateral related to derivative contracts on deposit with other financial institution counterparties at December 31, 2022.

Balance Sheet Offsetting

Balance Sheet Offsetting	12 Months Ended
Balance Sheet Offsetting	Dec. 31, 2022
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Balance Sheet Offsetting	Balance Sheet Offsetting and Repurchase Agreements Balance Sheet Offsetting. Certain financial instruments, including resell and repurchase agreements and derivatives, may be eligible for offset in the consolidated balance sheet and/or subject to master netting arrangements or similar agreements. Our derivative transactions with upstream financial institution counterparties are generally executed under International Swaps and Derivative Association (“ISDA”) master agreements which include “right of set-off” provisions. In such cases there is generally a legally enforceable right to offset recognized amounts and there may be an intention to settle such amounts on a net basis. Nonetheless, we do not generally offset such financial instruments for financial reporting purposes. Information about financial instruments that are eligible for offset in the consolidated balance sheet as of December 31, 2022 is presented in the following tables. Gross Amount Gross Amount Net Amount December 31, 2022 Financial assets: Derivatives: Loan/lease interest rate swaps and caps $ 85,691 $ — $ 85,691 Commodity swaps and options 33,302 — 33,302 Foreign currency forward/option contracts 1 — 1 Total derivatives 118,994 — 118,994 Resell agreements 87,150 — 87,150 Total $ 206,144 $ — $ 206,144 Financial liabilities: Derivatives: Loan/lease interest rate swaps $ 1,102 $ — $ 1,102 Commodity swaps and options 72,717 — 72,717 Foreign currency forward/option contracts 10 — 10 Total derivatives 73,829 — 73,829 Repurchase agreements 4,660,641 — 4,660,641 Total $ 4,734,470 $ — $ 4,734,470 Gross Amounts Not Offset Net Amount Financial Collateral Net December 31, 2022 Financial assets: Derivatives: Counterparty B $ 39,370 $ (24,500) $ (14,870) $ — Counterparty E 14,430 (47) (14,131) 252 Counterparty F 17,297 (17,297) — — Counterparty G 10,660 — (10,660) — Other counterparties 37,237 (20,684) (16,307) 246 Total derivatives 118,994 (62,528) (55,968) 498 Resell agreements 87,150 — (87,150) — Total $ 206,144 $ (62,528) $ (143,118) $ 498 Financial liabilities: Derivatives: Counterparty B $ 24,500 $ (24,500) $ — $ — Counterparty E 47 (47) — — Counterparty F 27,747 (17,297) (8,479) 1,971 Counterparty G — — — — Other counterparties 21,535 (20,684) (851) — Total derivatives 73,829 (62,528) (9,330) 1,971 Repurchase agreements 4,660,641 — (4,660,641) — Total $ 4,734,470 $ (62,528) $ (4,669,971) $ 1,971 Information about financial instruments that are eligible for offset in the consolidated balance sheet as of December 31, 2021 is presented in the following tables. Gross Amount Gross Amount Net Amount December 31, 2021 Financial assets: Derivatives: Loan/lease interest rate swaps and caps $ 4,446 $ — $ 4,446 Commodity swaps and options 18,864 — 18,864 Foreign currency forward/option contracts 29 — 29 Total derivatives 23,339 — 23,339 Resell agreements 7,903 — 7,903 Total $ 31,242 $ — $ 31,242 Financial liabilities: Derivatives: Loan/lease interest rate swaps $ 19,176 $ — $ 19,176 Commodity swaps and options 94,843 — 94,843 Total derivatives 114,019 — 114,019 Repurchase agreements 2,740,799 — 2,740,799 Total $ 2,854,818 $ — $ 2,854,818 Gross Amounts Not Offset Net Amount Financial Collateral Net December 31, 2021 Financial assets: Derivatives: Counterparty B $ 7,655 $ (7,655) $ — $ — Counterparty E 411 (411) — — Counterparty F 12,078 (12,078) — — Counterparty G 1,783 (1,783) — — Other counterparties 1,412 (1,412) — — Total derivatives 23,339 (23,339) — — Resell agreements 7,903 — (7,903) — Total $ 31,242 $ (23,339) $ (7,903) $ — Financial liabilities: Derivatives: Counterparty B $ 28,130 $ (7,655) $ (20,475) $ — Counterparty E 601 (411) (190) — Counterparty F 20,813 (12,078) (8,735) — Counterparty G 1,789 (1,783) (6) — Other counterparties 62,686 (1,412) (61,167) 107 Total derivatives 114,019 (23,339) (90,573) 107 Repurchase agreements 2,740,799 — (2,740,799) — Total $ 2,854,818 $ (23,339) $ (2,831,372) $ 107 Repurchase Agreements . We utilize securities sold under agreements to repurchase to facilitate the needs of our customers and to facilitate secured short-term funding needs. Securities sold under agreements to repurchase are stated at the amount of cash received in connection with the transaction. We monitor collateral levels on a continuous basis. We may be required to provide additional collateral based on the fair value of the underlying securities. Securities pledged as collateral under repurchase agreements are maintained with our safekeeping agents. The remaining contractual maturity of repurchase agreements in the consolidated balance sheets as of December 31, 2022 and December 31, 2021 is presented in the following tables. Remaining Contractual Maturity of the Agreements Overnight and Continuous Up to 30 Days 30-90 Days Greater than 90 Days Total December 31, 2022 Repurchase agreements: U.S. Treasury $ 3,735,061 $ — $ — $ — $ 3,735,061 Residential mortgage-backed securities 925,580 — — — 925,580 Total borrowings $ 4,660,641 $ — $ — $ — $ 4,660,641 Gross amount of recognized liabilities for repurchase agreements $ 4,660,641 Amounts related to agreements not included in offsetting disclosures above $ — December 31, 2021 Repurchase agreements: U.S. Treasury $ 1,342,591 $ — $ — $ — $ 1,342,591 Residential mortgage-backed securities 1,398,208 — — — 1,398,208 Total borrowings $ 2,740,799 $ — $ — $ — $ 2,740,799 Gross amount of recognized liabilities for repurchase agreements $ 2,740,799 Amounts related to agreements not included in offsetting disclosures above $ —

Fair Value Measurements

Fair Value Measurements	12 Months Ended
Fair Value Measurements	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The fair value of an asset or liability is the price that would be received to sell that asset or paid to transfer that liability in an orderly transaction occurring in the principal market (or most advantageous market in the absence of a principal market) for such asset or liability. In estimating fair value, we utilize valuation techniques that are consistent with the market approach, the income approach and/or the cost approach. Such valuation techniques are consistently applied. Inputs to valuation techniques include the assumptions that market participants would use in pricing an asset or liability. ASC Topic 820 establishes a fair value hierarchy for valuation inputs that gives the highest priority to quoted prices in active markets for identical assets or liabilities and the lowest priority to unobservable inputs. The fair value hierarchy is as follows: • Level 1 Inputs - Unadjusted quoted prices in active markets for identical assets or liabilities that the reporting entity has the ability to access at the measurement date. • Level 2 Inputs - Inputs other than quoted prices included in Level 1 that are observable for the asset or liability, either directly or indirectly. These might include quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable for the asset or liability (such as interest rates, volatilities, prepayment speeds, credit risks, etc.) or inputs that are derived principally from or corroborated by market data by correlation or other means. • Level 3 Inputs - Unobservable inputs for determining the fair values of assets or liabilities that reflect an entity’s own assumptions about the assumptions that market participants would use in pricing the assets or liabilities. In general, fair value is based upon quoted market prices, where available. If such quoted market prices are not available, fair value is based upon internally developed models that primarily use, as inputs, observable market-based parameters. Valuation adjustments may be made to ensure that financial instruments are recorded at fair value. These adjustments may include amounts to reflect counterparty credit quality and our creditworthiness, among other things, as well as unobservable parameters. Any such valuation adjustments are applied consistently over time. Our valuation methodologies may produce a fair value calculation that may not be indicative of net realizable value or reflective of future fair values. While management believes our valuation methodologies are appropriate and consistent with other market participants, the use of different methodologies or assumptions to determine the fair value of certain financial instruments could result in a different estimate of fair value at the reporting date. Furthermore, the reported fair value amounts have not been comprehensively revalued since the presentation dates, and therefore, estimates of fair value after the balance sheet date may differ significantly from the amounts presented herein. A more detailed description of the valuation methodologies used for assets and liabilities measured at fair value is set forth below. Transfers between levels of the fair value hierarchy are recognized on the actual date of the event or circumstances that caused the transfer, which generally coincides with our monthly and/or quarterly valuation process. Financial Assets and Financial Liabilities: Financial assets and financial liabilities measured at fair value on a recurring basis include the following: Securities Available for Sale . U.S. Treasury securities are reported at fair value utilizing Level 1 inputs. Other securities classified as available for sale are reported at fair value utilizing Level 2 inputs. For these securities, we obtain fair value measurements from an independent pricing service. The fair value measurements consider observable data that may include dealer quotes, market spreads, cash flows, the U.S. Treasury yield curve, live trading levels, trade execution data, market consensus prepayment speeds, credit information and the bond’s terms and conditions, among other things. We review the prices supplied by the independent pricing service, as well as their underlying pricing methodologies, for reasonableness and to ensure such prices are aligned with traditional pricing matrices. In general, we do not purchase investment portfolio securities that are esoteric or that have a complicated structure. Our entire portfolio consists of traditional investments, nearly all of which are U.S. Treasury obligations, federal agency bullet or mortgage pass-through securities, or general obligation or revenue based municipal bonds. Pricing for such instruments is fairly generic and is easily obtained. From time to time, we will validate prices supplied by the independent pricing service by comparison to prices obtained from third-party sources or derived using internal models. Trading Securities . U.S. Treasury securities and exchange-listed common stock are reported at fair value utilizing Level 1 inputs. Other securities classified as trading are reported at fair value utilizing Level 2 inputs in the same manner as described above for securities available for sale. Derivatives . Derivatives are generally reported at fair value utilizing Level 2 inputs, except for foreign currency contracts, which are reported at fair value utilizing Level 1 inputs. We obtain dealer quotations and utilize internally developed valuation models to value commodity swaps/options. We utilize internally developed valuation models and/or third-party models with observable market data inputs to validate the valuations provided by the dealers. Though there has never been a significant discrepancy in the valuations, should such a significant discrepancy arise, we would obtain price verification from a third-party dealer. We utilize internal valuation methods with observable market data inputs to estimate fair values of customer interest rate swaps, caps and floors. We also obtain dealer quotations for these derivatives for comparative purposes to assess the reasonableness of the model valuations. In cases where significant credit valuation adjustments are incorporated into the estimation of fair value, reported amounts are considered to have been derived utilizing Level 3 inputs. For purposes of potential valuation adjustments to our derivative positions, we evaluate the credit risk of our counterparties as well as ours. Accordingly, we have considered factors such as the likelihood of our default and the default of our counterparties, our net exposures and remaining contractual life, among other things, in determining if any fair value adjustments related to credit risk are required. Counterparty exposure is evaluated by netting positions that are subject to master netting arrangements, as well as considering the amount of collateral securing the position. We review our counterparty exposure on a regular basis, and, when necessary, appropriate business actions are taken to adjust the exposure. We also utilize this approach to estimate our own credit risk on derivative liability positions. To date, we have not realized any significant losses due to a counterparty’s inability to pay any net uncollateralized position. The change in value of derivative assets and derivative liabilities attributable to credit risk was not significant during the reported periods. The following tables summarize financial assets and financial liabilities measured at fair value on a recurring basis as of December 31, 2022 and 2021, segregated by the level of the valuation inputs within the fair value hierarchy utilized to measure fair value: Level 1 Level 2 Level 3 Total 2022 Securities available for sale: U.S. Treasury $ 5,051,587 $ — $ — $ 5,051,587 Residential mortgage-backed securities — 6,376,236 — 6,376,236 States and political subdivisions — 6,773,355 — 6,773,355 Other — 42,427 — 42,427 Trading account securities: U.S. Treasury 25,879 — — 25,879 States and political subdivisions — 2,166 — 2,166 Derivative assets: Interest rate swaps, caps and floors — 86,793 — 86,793 Commodity swaps and options — 106,685 — 106,685 Foreign currency forward/option contracts 11 — — 11 Derivative liabilities: Interest rate swaps, caps and floors — 95,533 — 95,533 Commodity swaps and options — 105,392 — 105,392 Foreign currency forward/option contracts 11 — — 11 Level 1 Level 2 Level 3 Total 2021 Securities available for sale: U.S. Treasury $ 2,179,433 $ — $ — $ 2,179,433 Residential mortgage-backed securities — 4,066,265 — 4,066,265 States and political subdivisions — 7,636,571 — 7,636,571 Other — 42,359 — 42,359 Trading account securities: U.S. Treasury 24,237 — — 24,237 States and political subdivisions — 925 — 925 Derivative assets: Interest rate swaps, caps and floors — 44,310 — 44,310 Commodity swaps and options — 114,757 — 114,757 Foreign currency forward contracts 33 — — 33 Derivative liabilities: Interest rate swaps, caps and floors — 25,261 — 25,261 Commodity swaps and options — 113,261 — 113,261 Foreign currency forward contracts 55 — — 55 Certain financial assets and financial liabilities are measured at fair value on a nonrecurring basis; that is, the instruments are not measured at fair value on an ongoing basis but are subject to fair value adjustments in certain circumstances (for example, when there is evidence of impairment). Financial assets measured at fair value on a non-recurring basis during the reported periods include certain impaired loans reported at the fair value of the underlying collateral if repayment is expected solely from the collateral. Collateral values are estimated using Level 2 inputs based on observable market data, typically in the case of real estate collateral, or Level 3 inputs based on customized discounting criteria, typically in the case of non-real estate collateral such as inventory, oil and gas reserves, accounts receivable, equipment or other business assets. The following table presents collateral dependent loans that were remeasured and reported at fair value through a specific allocation of the allowance for credit losses on loans based upon the fair value of the underlying collateral: 2022 2021 2020 Level 2 Carrying value before allocations $ 6,237 $ 1,333 $ 1,559 Specific (allocations) reversals of prior allocations (1,480) 214 (450) Fair value $ 4,757 $ 1,547 $ 1,109 Level 3 Carrying value before allocations $ 8,156 $ 16,074 $ 34,302 Specific (allocations) reversals of prior allocations 625 (5,178) (11,151) Fair value $ 8,781 $ 10,896 $ 23,151 Non-Financial Assets and Non-Financial Liabilities: We do not have any non-financial assets or non-financial liabilities measured at fair value on a recurring basis. From time to time, non-financial assets measured at fair value on a non-recurring basis may include certain foreclosed assets which, upon initial recognition, were remeasured and reported at fair value through a charge-off to the allowance for loan losses and certain foreclosed assets which, subsequent to their initial recognition, were remeasured at fair value through a write-down included in other non-interest expense. Such fair value measurements were not significant during the reported periods. Charge-offs recognized upon loan foreclosures are generally offset by general or specific allocations of the allowance for credit losses on loans and generally do not, and did not during the reported periods, significantly impact our credit loss expense. Regulatory guidelines require us to reevaluate the fair value of other real estate owned on at least an annual basis. While our policy is to comply with the regulatory guidelines, our general practice is to reevaluate the fair value of collateral supporting impaired collateral dependent loans on a quarterly basis. Thus, appraisals are generally not considered to be outdated, and we typically do not make any adjustments to the appraised values. ASC Topic 825, “Financial Instruments,” requires disclosure of the fair value of financial assets and financial liabilities, including those financial assets and financial liabilities that are not measured and reported at fair value on a recurring basis or non-recurring basis. The estimated fair value approximates carrying value for cash and cash equivalents, accrued interest and the cash surrender value of life insurance policies. The methodologies for other financial assets and financial liabilities that are not measured and reported at fair value on a recurring basis or non-recurring basis are discussed below: Loans . The estimated fair value approximates carrying value for variable-rate loans that reprice frequently and with no significant change in credit risk. The fair value of fixed-rate loans and variable-rate loans which reprice on an infrequent basis is estimated by discounting future cash flows using the current interest rates at which similar loans with similar terms would be made to borrowers of similar credit quality. An overall valuation adjustment is made for specific credit risks as well as general portfolio credit risk. Deposits . The estimated fair value approximates carrying value for demand deposits. The fair value of fixed-rate deposit liabilities with defined maturities is estimated by discounting future cash flows using the interest rates currently offered for deposits of similar remaining maturities. The estimated fair value of deposits does not take into account the value of our long-term relationships with depositors, commonly known as core deposit intangibles, which are separate intangible assets, and not considered financial instruments. Nonetheless, we would likely realize a core deposit premium if our deposit portfolio were sold in the principal market for such deposits. Borrowed Funds . The estimated fair value approximates carrying value for short-term borrowings. The fair value of long-term fixed-rate borrowings is estimated using quoted market prices, if available, or by discounting future cash flows using current interest rates for similar financial instruments. The estimated fair value approximates carrying value for variable-rate junior subordinated deferrable interest debentures that reprice quarterly. Loan Commitments, Standby and Commercial Letters of Credit . Our lending commitments have variable interest rates and “escape” clauses if the customer’s credit quality deteriorates. Therefore, the fair values of these items are not significant and are not included in the following table. The estimated fair values of financial instruments that are reported at amortized cost in our consolidated balance sheets, segregated by the level of valuation inputs within the fair value hierarchy utilized to measure fair value, were as follows: December 31, 2022 December 31, 2021 Carrying Estimated Carrying Estimated Financial assets: Level 2 inputs: Cash and cash equivalents $ 12,028,132 $ 12,028,132 $ 16,583,000 $ 16,583,000 Securities held to maturity 2,639,083 2,467,865 1,749,179 1,809,143 Cash surrender value of life insurance policies 190,188 190,188 190,139 190,139 Accrued interest receivable 243,682 243,682 179,111 179,111 Level 3 inputs: Loans, net 16,927,348 16,343,417 16,087,731 16,079,454 Financial liabilities: Level 2 inputs: Deposits 43,954,196 43,920,741 42,695,696 41,343,426 Federal funds purchased 51,650 51,650 25,925 25,925 Repurchase agreements 4,660,641 4,660,641 2,740,799 2,740,799 Junior subordinated deferrable interest debentures 123,069 123,712 123,011 123,712 Subordinated notes 99,335 97,014 99,178 111,430 Accrued interest payable 18,444 18,444 3,026 3,026 Under ASC Topic 825, entities may choose to measure eligible financial instruments at fair value at specified election dates. The fair value measurement option (i) may be applied instrument by instrument, with certain exceptions, (ii) is generally irrevocable and (iii) is applied only to entire instruments and not to portions of instruments. Unrealized gains and losses on items for which the fair value measurement option has been elected must be reported in earnings at each subsequent reporting date. During the reported periods, we had no financial instruments measured at fair value under the fair value measurement option.

Operating Segments

Operating Segments	12 Months Ended
Operating Segments	Dec. 31, 2022
Segment Reporting [Abstract]
Operating Segments	Operating Segments We are managed under a matrix organizational structure whereby our two primary operating segments, Banking and Frost Wealth Advisors, overlap a regional reporting structure. The regions are primarily based upon geographic location and include Austin, Corpus Christi, Dallas, Fort Worth, Houston, Permian Basin, Rio Grande Valley, San Antonio and Statewide. We are primarily managed based on the line of business structure. In that regard, all regions have the same lines of business, which have the same product and service offerings, have similar types and classes of customers and utilize similar service delivery methods. Pricing guidelines for products and services are the same across all regions. The regional reporting structure is primarily a means to scale the lines of business to provide a local, community focus for customer relations and business development. Banking and Frost Wealth Advisors are delineated by the products and services that each segment offers. The Banking operating segment includes both commercial and consumer banking services and Frost Insurance Agency. Commercial banking services are provided to corporations and other business clients and include a wide array of lending and cash management products. Consumer banking services include direct lending and depository services. Frost Insurance Agency provides insurance brokerage services to individuals and businesses covering corporate and personal property and casualty products, as well as group health and life insurance products. The Frost Wealth Advisors operating segment includes fee-based services within private trust, retirement services, and financial management services, including personal wealth management and securities brokerage services. A third operating segment, Non-Banks, is for the most part the parent holding company, as well as certain other insignificant non-bank subsidiaries of the parent that, for the most part, have little or no activity. The parent company’s principal activities include the direct and indirect ownership of our banking and non-banking subsidiaries and the issuance of debt and equity. Our principal source of revenue is dividends from our subsidiaries. The accounting policies of each reportable segment are the same as those of our consolidated entity except for the following items, which impact the Banking and Frost Wealth Advisors segments: (i) expenses for consolidated back-office operations and general overhead-type expenses such as executive administration, accounting and internal audit are allocated to operating segments based on estimated uses of those services, (ii) income tax expense for the individual segments is calculated essentially at the statutory rate, and (iii) the parent company records the tax expense or benefit necessary to reconcile to the consolidated total. We use a match-funded transfer pricing process to assess operating segment performance. The process helps us to (i) identify the cost or opportunity value of funds within each business segment, (ii) measure the profitability of a particular business segment by relating appropriate costs to revenues, (iii) evaluate each business segment in a manner consistent with its economic impact on consolidated earnings, and (iv) enhance asset and liability pricing decisions. Financial results by operating segment are detailed below. Certain prior period amounts have been reclassified to conform to the current presentation. Frost Wealth Advisors excludes off-balance-sheet managed and custody assets with a total fair value of $43.6 billion, $43.3 billion and $38.6 billion at December 31, 2022, 2021 and 2020. Banking Frost Non-Banks Consolidated 2022 Net interest income (expense) $ 1,295,467 $ 4,645 $ (8,829) $ 1,291,283 Credit loss expense 3,000 — — 3,000 Non-interest income 230,876 175,874 (1,932) 404,818 Non-interest expense 886,421 132,009 5,844 1,024,274 Income (loss) before income taxes 636,922 48,510 (16,605) 668,827 Income tax expense (benefit) 85,127 10,187 (5,637) 89,677 Net income (loss) 551,795 38,323 (10,968) 579,150 Preferred stock dividends — — 6,675 6,675 Net income (loss) available to common shareholders $ 551,795 $ 38,323 $ (17,643) $ 572,475 Revenues from (expenses to) external customers $ 1,526,343 $ 180,519 $ (10,761) $ 1,696,101 Average assets (in millions) $ 51,448 $ 57 $ 8 $ 51,513 Banking Frost Non-Banks Consolidated 2021 Net interest income (expense) $ 989,870 $ 2,138 $ (7,141) $ 984,867 Credit loss expense 54 9 — 63 Non-interest income 220,662 167,442 (1,376) 386,728 Non-interest expense 753,719 122,972 5,303 881,994 Income (loss) before income taxes 456,759 46,599 (13,820) 489,538 Income tax expense (benefit) 41,483 9,786 (4,810) 46,459 Net income (loss) 415,276 36,813 (9,010) 443,079 Preferred stock dividends — — 7,157 7,157 Net income (loss) available to common shareholders $ 415,276 $ 36,813 $ (16,167) $ 435,922 Revenues from (expenses to) external customers $ 1,210,532 $ 169,580 $ (8,517) $ 1,371,595 Average assets (in millions) $ 45,903 $ 70 $ 10 $ 45,983 2020 Net interest income (expense) $ 981,441 $ 2,776 $ (8,216) $ 976,001 Credit loss expense 241,230 — — 241,230 Non-interest income 321,136 145,268 (950) 465,454 Non-interest expense 718,519 123,630 6,755 848,904 Income (loss) before income taxes 342,828 24,414 (15,921) 351,321 Income tax expense (benefit) 20,347 5,127 (5,304) 20,170 Net income (loss) 322,481 19,287 (10,617) 331,151 Preferred stock dividends — — 2,016 2,016 Redemption of preferred stock — — 5,514 5,514 Net income (loss) available to common shareholders $ 322,481 $ 19,287 $ (18,147) $ 323,621 Revenues from (expenses to) external customers $ 1,302,577 $ 148,044 $ (9,166) $ 1,441,455 Average assets (in millions) $ 37,892 $ 59 $ 10 $ 37,961

Condensed Financial Statements

Condensed Financial Statements of Parent Company	12 Months Ended
Condensed Financial Statements of Parent Company	Dec. 31, 2022
Condensed Financial Information Disclosure [Abstract]
Condensed Financial Statements of Parent Company	Condensed Financial Statements of Parent Company Condensed financial statements pertaining only to Cullen/Frost Bankers, Inc. are presented below. Investments in subsidiaries are stated using the equity method of accounting. Condensed Balance Sheets December 31, 2022 2021 Assets: Cash $ 311,944 $ 471,875 Total cash and cash equivalents 311,944 471,875 Investment in subsidiaries 3,065,114 4,222,288 Accrued interest receivable and other assets 1,142 2,228 Total assets $ 3,378,200 $ 4,696,391 Liabilities: Junior subordinated deferrable interest debentures, net of unamortized issuance costs $ 123,069 $ 123,011 Subordinated notes, net of unamortized issuance costs 99,335 99,178 Accrued interest payable and other liabilities 18,568 34,647 Total liabilities 240,972 256,836 Shareholders’ Equity 3,137,228 4,439,555 Total liabilities and shareholders’ equity $ 3,378,200 $ 4,696,391 Condensed Statements of Income Year Ended December 31, 2022 2021 2020 Income: Dividend income paid by Frost Bank $ 51,711 $ 219,386 $ 298,884 Dividend income paid by non-banks 109 473 736 Interest and other income — 101 446 Total income 51,820 219,960 300,066 Expenses: Interest expense 8,829 7,141 8,216 Salaries and employee benefits 1,605 1,499 1,581 Other 6,316 5,867 6,833 Total expenses 16,750 14,507 16,630 Income before income taxes and equity in undistributed earnings of subsidiaries 35,070 205,453 283,436 Income tax benefit 5,641 4,899 5,406 Equity in undistributed earnings of subsidiaries 538,439 232,727 42,309 Net income 579,150 443,079 331,151 Preferred stock dividends 6,675 7,157 2,016 Redemption of preferred stock — — 5,514 Net income available to common shareholders $ 572,475 $ 435,922 $ 323,621 Condensed Statements of Cash Flows Year Ended December 31, 2022 2021 2020 Operating Activities: Net income $ 579,150 $ 443,079 $ 331,151 Adjustments to reconcile net income to net cash provided by operating activities: Equity in undistributed earnings of subsidiaries (538,439) (232,727) (42,309) Stock-based compensation 720 700 770 Net tax benefit from stock-based compensation 472 278 370 Net change in other assets and other liabilities (15,249) 23,890 (8,937) Net cash from operating activities 26,654 235,220 281,045 Investing Activities: Redemption of investment in non-bank subsidiary — 406 — Net cash from investing activities — 406 — Financing Activities: Principal payments on long-term borrowings — (13,403) — Redemption of Series A preferred stock — — (150,000) Proceeds from issuance of Series B preferred stock — — 145,452 Proceeds from stock option exercises 16,659 54,417 12,557 Proceeds from stock-based compensation activities of subsidiaries 17,602 12,053 13,148 Purchase of treasury stock (4,391) (3,864) (15,785) Treasury stock issued to 401(k) stock purchase plan — 1,749 10,307 Cash dividends paid on preferred stock (6,675) (7,157) (2,016) Cash dividends paid on common stock (209,780) (188,786) (180,584) Net cash from financing activities (186,585) (144,991) (166,921) Net change in cash and cash equivalents (159,931) 90,635 114,124 Cash and cash equivalents at beginning of year 471,875 381,240 267,116 Cash and cash equivalents at end of year $ 311,944 $ 471,875 $ 381,240

Accounting Standards Updates

Accounting Standards Updates	12 Months Ended
Accounting Standards Updates	Dec. 31, 2022
Accounting Standards Update and Change in Accounting Principle [Abstract]
Accounting Standards Updates	Accounting Standards Updates ASU 2016-13, “Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments.” ASU 2016-13 requires the measurement of all expected credit losses for financial assets held at the reporting date based on historical experience, current conditions, and reasonable and supportable forecasts and requires enhanced disclosures related to the significant estimates and judgments used in estimating credit losses, as well as the credit quality and underwriting standards of an organization’s portfolio. We adopted ASU 2016-13, as subsequently updated for certain clarifications, targeted relief and codification improvements, as of January 1, 2020 and recognized a cumulative effect adjustment reducing retained earnings by $29.3 million. See Note 1 - Summary of Significant Accounting Policies for additional information. ASU 2017-04, “Intangibles - Goodwill and Other (Topic 350) - Simplifying the Test for Goodwill Impairment.” ASU 2017-04 eliminates Step 2 from the goodwill impairment test which required entities to compute the implied fair value of goodwill. Under ASU 2017-04, an entity should perform its annual, or interim, goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount. An entity should recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. ASU 2017-04 became effective for us on January 1, 2020 and did not have a significant impact on our financial statements. ASU 2018-13, “Fair Value Measurement (Topic 820) - Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement.” ASU 2018-13 modifies the disclosure requirements on fair value measurements in Topic 820. The amendments in this update remove disclosures that no longer are considered cost beneficial, modify/clarify the specific requirements of certain disclosures, and add disclosure requirements identified as relevant. ASU 2018-13 became effective for us on January 1, 2020 and did not have a significant impact on our financial statements. ASU 2018-14, “Compensation - Retirement Benefits-Defined Benefit Plans-General (Subtopic 715-20).” ASU 2018-14 amends and modifies the disclosure requirements for employers that sponsor defined benefit pension or other post-retirement plans. The amendments in this update remove disclosures that no longer are considered cost beneficial, clarify the specific requirements of disclosures, and add disclosure requirements identified as relevant. ASU 2018-14 became effective for the year ended December 31, 2020 and did not have a significant impact on our financial statements. ASU 2018-15, “Intangibles - Goodwill and Other - Internal-Use Software (Subtopic 350-40) - Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract.” ASU 2018-15 clarifies certain aspects of ASU 2015-05, “Customer’s Accounting for Fees Paid in a Cloud Computing Arrangement,” which was issued in April 2015. Specifically, ASU 2018-15 aligns the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software (and hosting arrangements that include an internal-use software license). ASU 2018-15 does not affect the accounting for the service element of a hosting arrangement that is a service contract. ASU 2018-15 became effective for us on January 1, 2020 and did not have a significant impact on our financial statements. ASU 2019-12, “Income Taxes (Topic 740) - Simplifying the Accounting for Income Taxes.” The guidance issued in this update simplifies the accounting for income taxes by eliminating certain exceptions to the guidance in ASC 740 related to the approach for intraperiod tax allocation, the methodology for calculating income taxes in an interim period and the recognition for deferred tax liabilities for outside basis differences. ASU 2019-12 also simplifies aspects of the accounting for franchise taxes and enacted changes in tax laws or rates and clarifies the accounting for transactions that result in a step-up in the tax basis of goodwill. ASU 2019-12 became effective for us on January 1, 2021 and did not have a significant impact on our financial statements. ASU 2020-04, “Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting.” ASU 2020-04 provides optional expedients and exceptions for accounting related to contracts, hedging relationships and other transactions affected by reference rate reform if certain criteria are met. ASU 2020-04 applies only to contracts, hedging relationships, and other transactions that reference LIBOR or another reference rate expected to be discontinued because of reference rate reform and do not apply to contract modifications made and hedging relationships entered into or evaluated after December 31, 2022, except for hedging relationships existing as of December 31, 2022, that an entity has elected certain optional expedients for and that are retained through the end of the hedging relationship. ASU 2020-04 was effective upon issuance and, based upon the amendments provided in ASU 2022-06 discussed below, can generally be applied through December 31, 2024. The adoption of ASU 2020-04 did not significantly impact our financial statements. ASU 2020-08, “Codification Improvements to Subtopic 310-20, Receivables - Nonrefundable Fees and Other Costs.” ASU 2020-08 clarifies the accounting for the amortization of purchase premiums for callable debt securities with multiple call dates. ASU 2020-8 became effective for us on January 1, 2021 and did not have a significant impact on our financial statements. ASU 2020-09, “Debt (Topic 470): Amendments to SEC Paragraphs Pursuant to SEC Release No. 33-10762.” ASU 2020-9 amends the ASC to reflect the issuance of an SEC rule related to financial disclosure requirements for subsidiary issuers and guarantors of registered debt securities and affiliates whose securities are pledged as collateral for registered securities. ASU 2020-09 became effective for us on January 4, 2021, concurrent with the effective date of the SEC release, and did not have a significant impact on our financial statements. ASU 2021-01, “Reference Rate Reform (Topic 848): Scope.” ASU 2021-01 clarifies that certain optional expedients and exceptions in ASC 848 for contract modifications and hedge accounting apply to derivatives that are affected by the discounting transition. ASU 2021-01 also amends the expedients and exceptions in ASC 848 to capture the incremental consequences of the scope clarification and to tailor the existing guidance to derivative instruments affected by the discounting transition. ASU 2021-01 was effective upon issuance and, based upon the amendments provided in ASU 2022-06 discussed below, can generally be applied through December 31, 2024. The adoption of ASU 2021-01 did not significantly impact our financial statements. ASU 2022-01, “Derivatives and Hedging (Topic 815): Fair Value Hedging - Portfolio Layer Method.” Under prior guidance, entities can apply the last-of-layer hedging method to hedge the exposure of a closed portfolio of prepayable financial assets to fair value changes due to changes in interest rates for a portion of the portfolio that is not expected to be affected by prepayments, defaults, and other events affecting the timing and amount of cash flows. ASU 2022-01 expands the last-of-layer method, which permits only one hedge layer, to allow multiple hedged layers of a single closed portfolio. To reflect that expansion, the last-of-layer method is renamed the portfolio layer method. ASU 2022-01 also (i) expands the scope of the portfolio layer method to include non-prepayable financial assets, (ii) specifies eligible hedging instruments in a single-layer hedge, (iii) provides additional guidance on the accounting for and disclosure of hedge basis adjustments under the portfolio layer method and (iv) specifies how hedge basis adjustments should be considered when determining credit losses for the assets included in the closed portfolio. ASU 2022-01 will be effective for us on January 1, 2023. The adoption of ASU 2022-01 is not expected to have a significant impact on our financial statements. ASU 2022-02, “Financial Instruments - Credit Losses (Topic 326): Troubled Debt Restructurings and Vintage Disclosures.” ASU 2022-02 eliminates the accounting guidance for troubled debt restructurings in Accounting Standards Codification (“ASC”) Subtopic 310-40, Receivables - Troubled Debt Restructurings by Creditors, while enhancing disclosure requirements for certain loan refinancings and restructurings by creditors when a borrower is experiencing financial difficulty. Additionally, ASU 2022-02 requires entities to disclose current-period gross write-offs by year of origination for financing receivables and net investments in leases within the scope of ASC Subtopic 3126-20, Financial Instruments - Credit Losses - Measured at Amortized Cost. ASU 2022-02 will be effective for us on January 1, 2023. The adoption of ASU 2022-02 is not expected to have a significant impact on our financial statements. ASU 2022-03, “Fair Value Measurement (Topic 820): Fair Value Measurement of Equity Securities Subject to Contractual Sale Restrictions.” ASU 2022-03 clarifies that a contractual restriction on the sale of an equity security is not considered part of the unit of account of the equity security and, therefore, is not considered in measuring fair value. ASU 2022-03 also clarifies that an entity cannot, as a separate unit of account, recognize and measure a contractual sale restriction and requires certain new disclosures for equity securities subject to contractual sale restrictions. ASU 2022-03 will be effective for us on January 1, 2024 though early adoption is permitted. The adoption of ASU 2022-03 is not expected to have a significant impact on our financial statements. ASU No. 2022-06, “Reference Rate Reform (Topic 848): Deferral of the Sunset Date of Topic 848.” ASU 2022-06 extends the period of time preparers can utilize the reference rate reform relief guidance provided by ASU 2020-04 and ASU 2021-01, which are discussed above. ASU 2022-06, which was effective upon issuance, defers the sunset date of this prior guidance from December 31, 2022 to December 31, 2024, after which entities will no longer be permitted to apply the relief guidance in Topic 848. The adoption of ASU 2022-06 did not significantly impact our financial statements.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
Summary of Significant Accounting Policies (Policies)	Dec. 31, 2022
Accounting Policies [Abstract]
Nature Of Operations	Nature of Operations . Cullen/Frost Bankers, Inc. (“Cullen/Frost”) is a financial holding company and a bank holding company headquartered in San Antonio, Texas that provides, through its subsidiaries, a broad array of products and services throughout numerous Texas markets. The terms “Cullen/Frost,” “the Corporation,” “we,” “us” and “our” mean Cullen/Frost Bankers, Inc. and its subsidiaries, when appropriate. In addition to general commercial and consumer banking, other products and services offered include trust and investment management, insurance, brokerage, mutual funds, leasing, treasury management, capital markets advisory and item processing.
Basis of Presentation	Basis of Presentation. The consolidated financial statements include the accounts of Cullen/Frost and all other entities in which Cullen/Frost has a controlling financial interest. All significant intercompany balances and transactions have been eliminated in consolidation. The accounting and financial reporting policies we follow conform, in all material respects, to accounting principles generally accepted in the United States and to general practices within the financial services industry. We determine whether we have a controlling financial interest in an entity by first evaluating whether the entity is a voting interest entity or a variable interest entity (“VIE”) under accounting principles generally accepted in the United States. Voting interest entities are entities in which the total equity investment at risk is sufficient to enable the entity to finance itself independently and provides the equity holders with the obligation to absorb losses, the right to receive residual returns and the right to make decisions about the entity’s activities. We consolidate voting interest entities in which we have all, or at least a majority of, the voting interest. As defined in applicable accounting standards, VIEs are entities that lack one or more of the characteristics of a voting interest entity. A controlling financial interest in a VIE is present when an enterprise has both the power to direct the activities of the VIE that most significantly impact the VIE’s economic performance and an obligation to absorb losses or the right to receive benefits that could potentially be significant to the VIE. The enterprise with a controlling financial interest, known as the primary beneficiary, consolidates the VIE. Our wholly-owned subsidiary, Cullen/Frost Capital Trust II, is a VIE for which we are not the primary beneficiary and, as such, its accounts are not included in our consolidated financial statements. Acquisitions are accounted for using the purchase method with the operating results of the acquired companies included with our results of operations since their respective dates of acquisition.
Use of Estimates	Use of Estimates . The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements. Actual results could differ from those estimates. The allowance for credit losses on loans and off-balance-sheet credit exposures, the fair values of financial instruments and the status of contingencies are particularly subject to change.
Concentrations and Restrictions on Cash and Cash Equivalents	Concentrations and Restrictions on Cash and Cash Equivalents . We maintain deposits with other financial institutions in amounts that exceed federal deposit insurance coverage. Furthermore, federal funds sold are essentially uncollateralized loans to other financial institutions. Management regularly evaluates the credit risk associated with the counterparties to these transactions and believes that we are not exposed to any significant credit risks on cash and cash equivalents. As of December 31, 2022 and 2021, we had $3.2 million and $110.3 million in cash collateral on deposit with other financial institution counterparties to interest rate swap transactions.
Cash Flow Reporting	Cash Flow Reporting . Cash and cash equivalents include cash, deposits with other financial institutions that have an initial maturity of less than 90 days when acquired by us, federal funds sold and resell agreements. Net cash flows are reported for loans, deposit transactions and short-term borrowings. Additional cash flow information was as follows: Year Ended December 31, 2022 2021 2020 Cash paid for interest $ 169,020 $ 29,003 $ 49,300 Cash paid for income tax 100,000 39,852 44,140 Significant non-cash transactions: Exchange of real estate — 11,036 — Unsettled securities transactions 94,884 27,032 57,783 Loans foreclosed and transferred to other real estate owned and foreclosed assets 239 3,464 140 Right-of-use lease assets obtained in exchange for lessee operating lease liabilities 31,787 12,854 18,284 Treasury stock issued to 401(k) stock purchase plan — 1,749 10,307
Repurchase/Resell Agreements	Repurchase/Resell Agreements. We purchase certain securities under agreements to resell. The amounts advanced under these agreements represent short-term loans and are reflected as assets in the accompanying consolidated balance sheets. The securities underlying these agreements are book-entry securities. We also sell certain securities under agreements to repurchase. The agreements are treated as collateralized financing transactions and the obligations to repurchase securities sold are reflected as a liability in the accompanying consolidated balance sheets. The dollar amount of the securities underlying the agreements remains in the asset accounts.
Securities	Securities. Securities are classified as held to maturity and carried at amortized cost when management has the positive intent and ability to hold them until maturity. Securities to be held for indefinite periods of time are classified as available for sale and carried at fair value, with the unrealized holding gains and losses (those for which no allowance for credit losses are recorded) reported as a component of other comprehensive income, net of tax. Securities held for resale in anticipation of short-term market movements are classified as trading and are carried at fair value, with changes in unrealized holding gains and losses included in income. Management determines the appropriate classification of securities at the time of purchase. Securities with limited marketability, such as stock in the Federal Reserve Bank and the Federal Home Loan Bank, are carried at cost. Interest income on securities includes amortization of purchase premiums and discounts. Premiums and discounts on securities are generally amortized using the interest method with a constant effective yield without anticipating prepayments, except for mortgage-backed securities where prepayments are anticipated. Premiums on callable securities are amortized to their earliest call date. A security is placed on non-accrual status if (i) principal or interest has been in default for a period of 90 days or more or (ii) full payment of principal and interest is not expected. Interest accrued but not received for a security placed on non-accrual status is reversed against interest income. Gains and losses on sales are recorded on the trade date and are derived from the amortized cost of the security sold.
Loans	Loans . Loans are reported at the principal balance outstanding net of unearned discounts. Interest income on loans is reported on the level-yield method and includes amortization of deferred loan fees and costs over the terms of the individual loans to which they relate, or, in certain cases, over the average expected term for loans where deferred fees and costs are accounted for on a pooled basis. Net loan commitment fees or costs for commitment periods greater than one year are deferred and amortized into fee income or other expense on a straight-line basis over the commitment period. Income on direct financing leases is recognized on a basis that achieves a constant periodic rate of return on the outstanding investment. Further information regarding our accounting policies related to past due loans, non-accrual loans, impaired loans and troubled-debt restructurings is presented in Note 3 - Loans.
Credit Loss, Financial Instrument	Allowance for Credit Losses. As further discussed below, we adopted Accounting Standards Update (“ASU”) 2016-13, “Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments,” on January 1, 2020. Accounting Standards Codification (“ASC”) Topic 326 (“ASC 326”) replaced the previous “incurred loss” model for measuring credit losses, which encompassed allowances for current known and inherent losses within the portfolio, with an “expected loss” model, which encompasses allowances for losses expected to be incurred over the life of the portfolio. The new current expected credit loss (“CECL”) model requires the measurement of all expected credit losses for financial assets measured at amortized cost and certain off-balance- Allowance For Credit Losses - Held-to-Maturity Securities: The allowance for credit losses on held-to-maturity securities is a contra-asset valuation account, calculated in accordance with ASC 326, that is deducted from the amortized cost basis of held-to-maturity securities to present management's best estimate of the net amount expected to be collected. Held-to-maturity securities are charged-off against the allowance when deemed uncollectible by management. Adjustments to the allowance are reported in our income statement as a component of credit loss expense. Management measures expected credit losses on held-to-maturity securities on a collective basis by major security type with each type sharing similar risk characteristics and considers historical credit loss information that is adjusted for current conditions and reasonable and supportable forecasts. Management has made the accounting policy election to exclude accrued interest receivable on held-to-maturity securities from the estimate of credit losses. Further information regarding our policies and methodology used to estimate the allowance for credit losses on held-to-maturity securities is presented in Note 2 - Securities. Allowance For Credit Losses - Available-for-Sale Securities: For available-for-sale securities in an unrealized loss position, we first assess whether (i) we intend to sell or (ii) it is more likely than not that we will be required to sell the security before recovery of its amortized cost basis. If either case is affirmative, any previously recognized allowances are charged-off and the security's amortized cost is written down to fair value through income. If neither case is affirmative, the security is evaluated to determine whether the decline in fair value has resulted from credit losses or other factors. In making this assessment, management considers the extent to which fair value is less than amortized cost, any changes to the rating of the security by a rating agency and any adverse conditions specifically related to the security, among other factors. If this assessment indicates that a credit loss exists, the present value of cash flows expected to be collected from the security are compared to the amortized cost basis of the security. If the present value of cash flows expected to be collected is less than the amortized cost basis, a credit loss exists and an allowance for credit losses is recorded for the credit loss, limited by the amount that the fair value is less than the amortized cost basis. Any impairment that has not been recorded through an allowance for credit losses is recognized in other comprehensive income. Adjustments to the allowance are reported in our income statement as a component of credit loss expense. Management has made the accounting policy election to exclude accrued interest receivable on available-for-sale securities from the estimate of credit losses. Available-for-sale securities are charged-off against the allowance or, in the absence of any allowance, written down through income when deemed uncollectible by management or when either of the aforementioned criteria regarding intent or requirement to sell is met. Prior to the adoption of ASU 2016-13, declines in the fair value of held-to-maturity and available-for-sale securities below their cost that were deemed to be other than temporary were reflected in earnings as realized losses. In estimating other-than-temporary impairment losses prior to January 1, 2020, management considered, among other things, (i) the length of time and the extent to which the fair value had been less than cost, (ii) the financial condition and near-term prospects of the issuer and (iii) the intent and our ability to retain our investment in the issuer for a period of time sufficient to allow for any anticipated recovery in fair value.
Allowance for Credit Losses Loans	Allowance for Credit Losses - Loans: The allowance for credit losses on loans is a contra-asset valuation account, calculated in accordance with ASC 326, that is deducted from the amortized cost basis of loans to present management's best estimate of the net amount expected to be collected. Loans are charged-off against the allowance when deemed uncollectible by management. Expected recoveries do not exceed the aggregate of amounts previously charged-off and expected to be charged-off. Adjustments to the allowance are reported in our income statement as a component of credit loss expense. Management has made the accounting policy election to exclude accrued interest receivable on loans from the estimate of credit losses. Further information regarding our policies and methodology used to estimate the allowance for credit losses on loans is presented in Note 3 - Loans. Allowance For Credit Losses - Loans. The allowance for credit losses on loans is a contra-asset valuation account, calculated in accordance with ASC 326, that is deducted from the amortized cost basis of loans to present the net amount expected to be collected. The amount of the allowance represents management's best estimate of current expected credit losses on loans considering available information, from internal and external sources, relevant to assessing collectibility over the loans' contractual terms, adjusted for expected prepayments when appropriate. The contractual term excludes expected extensions, renewals and modifications unless (i) management has a reasonable expectation that a loan to an individual borrower that is experiencing financial difficulty will be modified or (ii) such extension or renewal options are not unconditionally cancellable by us and, in such cases, the borrower is likely to meet applicable conditions and likely to request extension or renewal. Relevant available information includes historical credit loss experience, current conditions and reasonable and supportable forecasts. While historical credit loss experience provides the basis for the estimation of expected credit losses, adjustments to historical loss information may be made for differences in current portfolio-specific risk characteristics, environmental conditions or other relevant factors. The allowance for credit losses is measured on a collective basis for portfolios of loans when similar risk characteristics exist. Loans that do not share risk characteristics are evaluated for expected credit losses on an individual basis and excluded from the collective evaluation. Expected credit losses for collateral dependent loans, including loans where the borrower is experiencing financial difficulty but foreclosure is not probable, are based on the fair value of the collateral at the reporting date, adjusted for selling costs as appropriate. Credit loss expense related to loans reflects the totality of actions taken on all loans for a particular period including any necessary increases or decreases in the allowance related to changes in credit loss expectations associated with specific loans or pools of loans. Portions of the allowance may be allocated for specific credits; however, the entire allowance is available for any credit that, in management’s judgment, should be charged off. While management utilizes its best judgment and information available, the ultimate appropriateness of the allowance is dependent upon a variety of factors beyond our control, including the performance of our loan portfolio, the economy, changes in interest rates and the view of the regulatory authorities toward loan classifications. In calculating the allowance for credit losses, most loans are segmented into pools based upon similar characteristics and risk profiles. Common characteristics and risk profiles include the type/purpose of loan, underlying collateral, geographical similarity and historical/expected credit loss patterns. In developing these loan pools for the purposes of modeling expected credit losses, we also analyzed the degree of correlation in how loans within each portfolio respond when subjected to varying economic conditions and scenarios as well as other portfolio stress factors. For modeling purposes, our loan pools include (i) commercial and industrial and energy - non-revolving, (ii) commercial and industrial and energy - revolving, (iii) commercial real estate - owner occupied, (iv) commercial real estate - non-owner occupied, (v) commercial real estate - construction/land development, (vi) consumer real estate and (vii) consumer and other. We periodically reassess each pool to ensure the loans within the pool continue to share similar characteristics and risk profiles and to determine whether further segmentation is necessary. For each loan pool, we measure expected credit losses over the life of each loan utilizing a combination of models which measure (i) probability of default (“PD”), which is the likelihood that loan will stop performing/default, (ii) probability of attrition (“PA”), which is the likelihood that a loan will pay-off prior to maturity, (iii) loss given default (“LGD”), which is the expected loss rate for loans in default and (iv) exposure at default (“EAD”), which is the estimated outstanding principal balance of the loans upon default, including the expected funding of unfunded commitments outstanding as of the measurement date. For certain commercial loan portfolios, the PD is calculated using a transition matrix to determine the likelihood of a customer’s risk grade migrating from one specified range of risk grades to a different specified range. Expected credit losses are calculated as the product of PD (adjusted for attrition), LGD and EAD. This methodology builds on default probabilities already incorporated into our risk grading process by utilizing pool-specific historical loss rates to calculate expected credit losses. These pool-specific historical loss rates may be adjusted for current macroeconomic assumptions, as further discussed below, and other factors such as differences in underwriting standards, portfolio mix, or when historical asset terms do not reflect the contractual terms of the financial assets being evaluated as of the measurement date. Each time we measure expected credit losses, we assess the relevancy of historical loss information and consider any necessary adjustments to address any differences in asset-specific characteristics. Due to their short-term nature, expected credit losses for overdrafts included in consumer and other loans are based solely upon a weighting of recent historical charge-offs over a period of three years. The measurement of expected credit losses is impacted by loan/borrower attributes and certain macroeconomic variables. Significant loan/borrower attributes utilized in our modeling processes include, among other things, (i) origination date, (ii) maturity date, (iii) payment type, (iv) collateral type and amount, (v) current risk grade, (vi) current unpaid balance and commitment utilization rate, (vii) payment status/delinquency history and (viii) expected recoveries of previously charged-off amounts. Significant macroeconomic variables utilized in our modeling processes include, among other things, (i) Gross State Product for Texas and U.S. Gross Domestic Product, (ii) selected market interest rates including U.S. Treasury rates, bank prime rate, 30-year fixed mortgage rate, BBB corporate bond rate, among others, (iii) unemployment rates, (iv) commercial and residential property prices in Texas and the U.S. as a whole, (v) West Texas Intermediate crude oil price and (vi) total stock market index. PD and PA were estimated by analyzing internally-sourced data related to historical performance of each loan pool over a complete economic cycle. PD and PA are adjusted to reflect the current impact of certain macroeconomic variables as well as their expected changes over a reasonable and supportable forecast period. We have determined that we are reasonably able to forecast the macroeconomic variables used in our modeling processes with an acceptable degree of confidence for a total of two years with the last twelve months of the forecast period encompassing a reversion process whereby the forecasted macroeconomic variables are reverted to their historical mean utilizing a rational, systematic basis. The macroeconomic variables utilized as inputs in our modeling processes were subjected to a variety of analysis procedures and were selected primarily based on statistical relevancy and correlation to our historical credit losses. By reverting these modeling inputs to their historical mean and considering loan/borrower specific attributes, our models are intended to yield a measurement of expected credit losses that reflects our average historical loss rates for periods subsequent to the twelve-month reversion period. The LGD is based on historical recovery averages for each loan pool, adjusted to reflect the current impact of certain macroeconomic variables as well as their expected changes over a two-year forecast period, with the final twelve months of the forecast period encompassing a reversion process, which management considers to be both reasonable and supportable. This same forecast/reversion period is used for all macroeconomic variables used in all of our models. EAD is estimated using a linear regression model that estimates the average percentage of the loan balance that remains at the time of a default event. Management qualitatively adjusts model results for risk factors that are not considered within our modeling processes but are nonetheless relevant in assessing the expected credit losses within our loan pools. These qualitative factor (“Q-Factor”) and other qualitative adjustments may increase or decrease management's estimate of expected credit losses by a calculated percentage or amount based upon the estimated level of risk. The various risks that may be considered in making Q-Factor and other qualitative adjustments include, among other things, the impact of (i) changes in lending policies and procedures, including changes in underwriting standards and practices for collections, write-offs, and recoveries, (ii) actual and expected changes in international, national, regional, and local economic and business conditions and developments that affect the collectibility of the loan pools, (iii) changes in the nature and volume of the loan pools and in the terms of the underlying loans, (iv) changes in the experience, ability, and depth of our lending management and staff, (v) changes in volume and severity of past due financial assets, the volume of non-accrual assets, and the volume and severity of adversely classified or graded assets, (vi) changes in the quality of our credit review function, (vii) changes in the value of the underlying collateral for loans that are non-collateral dependent, (viii) the existence, growth, and effect of any concentrations of credit and (ix) other factors such as the regulatory, legal and technological environments; competition; and events such as natural disasters or health pandemics. In some cases, management may determine that an individual loan exhibits unique risk characteristics which differentiate the loan from other loans within our loan pools. In such cases, the loans are evaluated for expected credit losses on an individual basis and excluded from the collective evaluation. Specific allocations of the allowance for credit losses are determined by analyzing the borrower’s ability to repay amounts owed, collateral deficiencies, the relative risk grade of the loan and economic conditions affecting the borrower’s industry, among other things. A loan is considered to be collateral dependent when, based upon management's assessment, the borrower is experiencing financial difficulty and repayment is expected to be provided substantially through the operation or sale of the collateral. In such cases, expected credit losses are based on the fair value of the collateral at
Off-Balance-Sheet Credit Exposure	Allowance For Credit Losses - Off-Balance-Sheet Credit Exposures: The allowance for credit losses on off-balance-sheet credit exposures is a liability account, calculated in accordance with ASC 326, representing expected credit losses over the contractual period for which we are exposed to credit risk resulting from a contractual obligation to extend credit. No allowance is recognized if we have the unconditional right to cancel the obligation. The allowance is reported as a component of accrued interest payable and other liabilities in our consolidated balance sheets. Adjustments to the allowance are reported in our income statement as a component of credit loss expense. Further information regarding our policies and methodology used to estimate the allowance for credit Allowance For Credit Losses - Off-Balance-Sheet Credit Exposures. The allowance for credit losses on off-balance-sheet credit exposures is a liability account, calculated in accordance with ASC 326, representing expected credit losses over the contractual period for which we are exposed to credit risk resulting from a contractual obligation to extend credit. No allowance is recognized if we have the unconditional right to cancel the obligation. Off-balance-sheet credit exposures primarily consist of amounts available under outstanding lines of credit and letters of credit detailed in the table above. For the period of exposure, the estimate of expected credit losses considers both the likelihood that funding will occur and the amount expected to be funded over the estimated remaining life of the commitment or other off-balance-sheet exposure. The likelihood and expected amount of funding are based on historical utilization rates. The amount of the allowance represents management's best estimate of expected credit losses on commitments expected to be funded over the contractual life of the commitment. Estimating credit losses on amounts expected to be funded uses the same methodology as described for loans in Note 3 - Loans as if such commitments were funded.
Premises and Equipment	Premises and Equipment. Land is carried at cost. Building and improvements, and furniture and equipment are carried at cost, less accumulated depreciation, computed principally by the straight-line method based on the estimated useful lives of the related property. Leasehold improvements are generally depreciated over the lesser of the term of the respective leases or the estimated useful lives of the improvements. We lease certain office facilities and office equipment under operating leases. We also own certain office facilities which we lease to outside parties under operating lessor leases; however, such leases are not significant. For operating leases other than those considered to be short-term, we recognize lease right-of-use assets and related lease liabilities. Such amounts are reported as components of premises and equipment and accrued interest payable and other liabilities, respectively, on our accompanying consolidated balance sheet. We do not recognize short-term operating leases on our balance sheet. A short-term operating lease has an original term of 12 months or less and does not have a purchase option that is likely to be exercised. In recognizing lease right-of-use assets and related lease liabilities, we account for lease and non-lease components (such as taxes, insurance, and common area maintenance costs) separately as such amounts are generally readily determinable under our lease contracts. Lease payments over the expected term are discounted using our incremental borrowing rate referenced to the Federal Home Loan Bank Secure Connect advance rates for borrowings of similar term. We also consider renewal and termination options in the determination of the term of the lease. If it is reasonably certain that a renewal or termination option will be exercised, the effects of such options are included in the determination of the expected lease term. Generally, we cannot be reasonably certain about whether or not we will renew a lease until such time the lease is within the last two years of the existing lease term. However, renewal options related to our regional headquarters facilities or operations centers are evaluated on a case-by-case basis, typically in advance of such time frame. When we are reasonably certain that a renewal option will be exercised, we measure/remeasure the right-of-use asset and related lease liability using the lease payments specified for the renewal period or, if such amounts are unspecified, we generally assume an increase (evaluated on a case-by-case basis in light of prevailing market conditions) in the lease payment over the final period of the existing lease term.
Foreclosed Assets	Foreclosed Assets . Assets acquired through or instead of loan foreclosure are held for sale and are initially recorded at fair value less estimated selling costs when acquired, establishing a new cost basis. Write-downs occurring at acquisition are charged against the allowance for credit losses on loans. Foreclosed assets are included in other assets in the accompanying consolidated balance sheets and totaled $964 thousand and $3.4 million at December 31, 2022 and 2021. Regulatory guidelines require us to reevaluate the fair value of foreclosed assets on at least an annual basis. Our policy is to comply with the regulatory guidelines. If the fair value of the asset declines, a write-down is recorded through other non-interest expense along with other expenses related to maintaining the properties. The valuation of foreclosed assets is subjective in nature and may be adjusted in the future because of changes in economic conditions. There were no write-downs of foreclosed assets in 2022, while write-downs of foreclosed assets totaled $14 thousand in 2021 and $231 thousand in 2020. There were no significant concentrations of any properties, to which the aforementioned write-downs relate, in any single geographic region.
Goodwill	Goodwill. Goodwill represents the excess of the cost of businesses acquired over the fair value of the net assets acquired. Goodwill is assigned to reporting units and tested for impairment at least annually on October 1st, or on an interim basis if an event occurs or circumstances change that would more likely than not reduce the fair value of the reporting unit below its carrying value. See Note 5 - Goodwill and Other Intangible Assets.
Intangibles and Other Long Lived Assets	Intangibles and Other Long-Lived Assets . Intangible assets are acquired assets that lack physical substance but can be distinguished from goodwill because of contractual or other legal rights or because the asset is capable of being sold or exchanged either on its own or in combination with a related contract, asset, or liability. Our intangible assets relate to core deposits, non-compete agreements and customer relationships. Intangible assets with definite useful lives are amortized on an accelerated basis over their estimated life. Intangible assets with indefinite useful lives are not amortized until their lives are determined to be definite. Intangible assets, premises and equipment and other long-lived assets are tested for impairment whenever events or changes in circumstances indicate the carrying amount of the assets may not be recoverable from future undiscounted cash flows. If impaired, the assets are recorded at fair value. See Note 5 - Goodwill and Other Intangible Assets.
Revenue Recognition	Revenue Recognition . In general, for revenue not associated with financial instruments, guarantees and lease contracts, we apply the following steps when recognizing revenue from contracts with customers: (i) identify the contract, (ii) identify the performance obligations, (iii) determine the transaction price, (iv) allocate the transaction price to the performance obligations and (v) recognize revenue when a performance obligation is satisfied. Our contracts with customers are generally short term in nature, typically due within one year or less or cancellable by us or our customer upon a short notice period. Performance obligations for our customer contracts are generally satisfied at a single point in time, typically when the transaction is complete, or over time. For performance obligations satisfied over time, we primarily use the output method, directly measuring the value of the products/services transferred to the customer, to determine when performance obligations have been satisfied. We typically receive payment from customers and recognize revenue concurrent with the satisfaction of our performance obligations. In most cases, this occurs within a single financial reporting period. For payments received in advance of the satisfaction of performance obligations, revenue recognition is deferred until such time as the performance obligations have been satisfied. In cases where we have not received payment despite satisfaction of our performance obligations, we accrue an estimate of the amount due in the period our performance obligations have been satisfied. For contracts with variable components, only amounts for which collection is probable are accrued. We generally act in a principal capacity, on our own behalf, in most of our contracts with customers. In such transactions, we recognize revenue and the related costs to provide our services on a gross basis in our financial statements. In some cases, we act in an agent capacity, deriving revenue through assisting other entities in transactions with our customers. In such transactions, we recognize revenue and the related costs to provide our services on a net basis in our financial statements. These transactions recognized on a net basis primarily relate to insurance and brokerage commissions and fees derived from our customers' use of various interchange and ATM/debit card networks.
Stock Based Compensation	Share-Based Payments . Compensation expense for stock options, non-vested stock awards/stock units and deferred stock units is based on the fair value of the award on the measurement date, which, for us, is the date of the grant and is recognized ratably over the service period of the award. Compensation expense for performance stock units is based on the fair value of the award on the measurement date, which, for us, is the date of the grant and is recognized over the service period of the award based upon the probable number of units expected to vest. The fair value of stock options is estimated using a binomial lattice-based valuation model. The fair value of non-vested stock awards/stock units and deferred stock units is generally the market price of our stock on the date of grant. The fair value of performance stock units is generally the market price of our stock on the date of grant discounted by the present value of the dividends expected to be paid on our common stock during the service period of the award because dividend equivalent payments on performance stock units are deferred until such time that the units vest and shares are issued. The impact of forfeitures of share-based payment awards on compensation expense is recognized as forfeitures occur. We have three active stock compensation plans (the 2005 Omnibus Incentive Plan, the 2007 Outside Directors Incentive Plan and the 2015 Omnibus Incentive Plan). All of the plans have been approved by our shareholders. During 2015, the 2015 Omnibus Incentive Plan (“2015 Plan”) was established to replace both the 2005 Omnibus Incentive Plan (“2005 Plan”) and the 2007 Outside Directors Incentive Plan (the “2007 Directors Plan”). All remaining shares authorized for grant under the superseded 2005 Plan and 2007 Directors Plan were transferred to the 2015 Plan. Our stock compensation plans were established to (i) motivate superior performance by means of performance-related incentives, (ii) encourage and provide for the acquisition of an ownership interest in our company by employees and non-employee directors and (iii) enable us to attract and retain qualified and competent persons as employees and to serve as members of our board of directors. Under the 2015 Plan, we may grant, among other things, nonqualified stock options, incentive stock options, stock awards, stock appreciation rights, restricted stock units, performance share units or any combination thereof to certain employees and non-employee directors. Any of the authorized shares may be used for any type of award Options awarded to employees generally have a ten four three four Performance stock units represent shares potentially issuable in the future. For performance stock units granted in 2022 and 2021, issuance is based upon the measure of our achievement of growth in adjusted net revenue, averaged over the three-year performance period, compared to the 2022 and 2021 base-year amounts, respectively. Adjusted net revenue for each three-year performance period is calculated as the sum of taxable-equivalent net interest income (excluding the effects of PPP lending) and non-interest income, reduced by non-interest expense (excluding the effects of PPP lending) and net charge-offs. The 2022 and 2021 base-year adjusted net revenue amounts of approximately $713.8 million and $415.9 million, respectively, were calculated as the sum of taxable-equivalent net interest income (excluding the effects of PPP lending) and non-interest income, reduced by non-interest expense (excluding the effects of PPP lending) and the product of average total loans (excluding PPP loans) and 0.30%. The ultimate number of shares issuable under each performance award is the product of the award target and the award payout percentage for the given level of achievement. The level of achievement is measured as the amount by which adjusted net revenue, averaged over a three-year performance period, exceeds the 2022 and 2021 base-year amounts, as applicable, stated as an average growth percentage. The award payout percentages by level of achievement for both the 2022 and 2021 awards are as follows: (i) less than 13% average growth pays out at 0% of target, (ii) 13% average growth pays out at 50% of target, (iii) 19% average growth pays out at 100% of target and (iv) 25% average growth or more pays out at 150% of target. Achievement between the aforementioned average growth percentages will result in an award payout percentage determined based on straight-line interpolation between the percentages. For performance stock units granted prior to 2021, issuance is based upon the measure of our achievement of relative return on assets over a three-year performance period compared to an identified peer group's achievement of relative return on assets over the same three-year performance period. The ultimate number of shares issuable under each performance award is the product of the award target and the award payout percentage for the given level of achievement. The level of achievement is measured as the percentile rank of relative return on assets among the peer group. The award payout percentages by level of achievement are as follows: (i) less than 25th percentile pays out at 0% of target, (ii) 25th percentile pays out at 50% of target, (iii) 50th percentile pays out at 100% of target and (iv) 75th percentile or more pays out at 150% of target. Achievement between the aforementioned percentiles will result in an award payout percentage determined based on straight-line interpolation between the percentiles. Performance stock units are eligible to receive equivalent dividend payments as such dividends are declared on our common stock during the performance period. Equivalent dividend payments are based upon the ultimate number of shares issued under each performance award and are deferred until such time that the units vest and shares are issued. Valuation of Stock-Based Compensation . For the purposes of recognizing stock-based compensation expense, the fair value of non-vested stock awards/stock units and deferred stock units is generally the market price of the stock on the measurement date, which, for us, is the date of the award. The fair value of performance stock units is determined in a similar manner except that the market price of the stock on the measurement date is discounted by the present value of the dividends expected to be paid on our common stock during the service period of the award because dividend equivalent payments on performance stock units are deferred until such time that the units vest and shares are issued. In applying this discount to the market price of our stock on the measurement date, we assumed we would pay a flat quarterly dividend during the service period equal to our most recent dividend payment, which was $0.87, $0.75 and $0.72 in 2022, 2021 and 2020, respectively, discounted at a weighted-average risk-free rate of 4.45%, 0.77% and 0.19% in 2022, 2021 and 2020, respectively.
Advertising Costs	Advertising Costs. Advertising costs are expensed as incurred.
Income Taxes	Income Taxes . Income tax expense is the total of the current year income tax due or refundable and the change in deferred tax assets and liabilities (excluding deferred tax assets and liabilities related to business combinations or components of other comprehensive income). Deferred tax assets and liabilities are the expected future tax amounts for the temporary differences between carrying amounts and tax bases of assets and liabilities, computed using enacted tax rates. A valuation allowance, if needed, reduces deferred tax assets to the expected amount most likely to be realized. Realization of deferred tax assets is dependent upon the generation of a sufficient level of future taxable income. Although realization is not assured, management believes it is more likely than not that all of the deferred tax assets will be realized. Interest and/or penalties related to income taxes are reported as a component of income tax expense. The income tax effects related to settlements of share-based payment awards are reported in earnings as an increase (or decrease) to income tax expense. See Note 13 - Income Taxes. We file a consolidated income tax return with our subsidiaries. Federal income tax expense or benefit has been allocated to subsidiaries on a separate return basis.
Basic and Diluted Earnings Per Common Share	Basic and Diluted Earnings Per Common Share. Earnings per common share is computed using the two-class method prescribed under ASC Topic 260, “Earnings Per Share.” ASC 260 provides that unvested share-based payment awards that contain nonforfeitable rights to dividends or dividend equivalents (whether paid or unpaid) are participating securities and shall be included in the computation of earnings per share pursuant to the two-class method. We have determined that our outstanding non-vested stock awards/stock units and deferred stock units are participating securities. Earnings Per Common Share . Earnings per common share is computed using the two-class method. Basic earnings per common share is computed by dividing net earnings allocated to common stock by the weighted-average number of common shares outstanding during the applicable period, excluding outstanding participating securities. Participating securities include non-vested stock awards/stock units, deferred stock units and performance stock units (during the performance period), though no actual shares of common stock related to any type of stock unit have been issued. Non-vested stock awards/stock units and deferred stock units are considered participating securities because holders of these securities receive non-forfeitable dividends at the same rate as holders of our common stock. Holders of performance stock units receive dividend equivalent payments for dividends paid during the performance period at the vesting date of the award based upon the number of units that ultimately vest. Diluted earnings per common share is computed using the weighted-average number of shares determined for the basic earnings per common share computation plus the dilutive effect of stock compensation using the treasury stock method.
Comprehensive Income	Comprehensive Income. Comprehensive income includes all changes in shareholders’ equity during a period, except those resulting from transactions with shareholders. Besides net income, other components of our comprehensive income include the after tax effect of changes in the net unrealized gain/loss on securities available for sale, changes in the net unrealized gain on securities transferred to held to maturity and changes in the net actuarial gain/loss on defined benefit post-retirement benefit plans. See Note 14 - Other Comprehensive Income (Loss).
Derivative Financial Instruments	Derivative Financial Instruments . Our hedging policies permit the use of various derivative financial instruments to manage interest rate risk or to hedge specified assets and liabilities. All derivatives are recorded at fair value on our balance sheet. Derivatives executed with the same counterparty are generally subject to master netting arrangements, however, fair value amounts recognized for derivatives and fair value amounts recognized for the right/obligation to reclaim/return cash collateral are not offset for financial reporting purposes. We may be required to recognize certain contracts and commitments as derivatives when the characteristics of those contracts and commitments meet the definition of a derivative. To qualify for hedge accounting, derivatives must be highly effective at reducing the risk associated with the exposure being hedged and must be designated as a hedge at the inception of the derivative contract. We consider a hedge to be highly effective if the change in fair value of the derivative hedging instrument is within 80% to 125% of the opposite change in the fair value of the hedged item attributable to the hedged risk. If derivative instruments are designated as hedges of fair values, and such hedges are highly effective, both the change in the fair value of the hedge and the hedged item are included in current earnings. Fair value adjustments related to cash flow hedges are recorded in other comprehensive income and are reclassified to earnings when the hedged transaction is reflected in earnings. Ineffective portions of hedges are reflected in earnings as they occur. Actual cash receipts and/or payments and related accruals on derivatives related to hedges are recorded as adjustments to the interest income or interest expense associated with the hedged item. During the life of the hedge, we formally assess whether derivatives designated as hedging instruments continue to be highly effective in offsetting changes in the fair value or cash flows of hedged items. If it is determined that a hedge has ceased to be highly effective, we will discontinue hedge accounting prospectively. At such time, previous adjustments to the carrying value of the hedged item are reversed into current earnings and the derivative instrument is reclassified to a trading position recorded at fair value.
Fair Value Measurements	Fair Value Measurements . In general, fair values of financial instruments are based upon quoted market prices, where available. If such quoted market prices are not available, fair value is based upon internally developed models that primarily use, as inputs, observable market-based parameters. Valuation adjustments may be made to ensure that financial instruments are recorded at fair value. These adjustments may include amounts to reflect counterparty credit quality and our creditworthiness, among other things, as well as unobservable parameters. Any such valuation adjustments are applied consistently over time. See Note 17 - Fair Value Measurements. The fair value of an asset or liability is the price that would be received to sell that asset or paid to transfer that liability in an orderly transaction occurring in the principal market (or most advantageous market in the absence of a principal market) for such asset or liability. In estimating fair value, we utilize valuation techniques that are consistent with the market approach, the income approach and/or the cost approach. Such valuation techniques are consistently applied. Inputs to valuation techniques include the assumptions that market participants would use in pricing an asset or liability. ASC Topic 820 establishes a fair value hierarchy for valuation inputs that gives the highest priority to quoted prices in active markets for identical assets or liabilities and the lowest priority to unobservable inputs. The fair value hierarchy is as follows: • Level 1 Inputs - Unadjusted quoted prices in active markets for identical assets or liabilities that the reporting entity has the ability to access at the measurement date. • Level 2 Inputs - Inputs other than quoted prices included in Level 1 that are observable for the asset or liability, either directly or indirectly. These might include quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable for the asset or liability (such as interest rates, volatilities, prepayment speeds, credit risks, etc.) or inputs that are derived principally from or corroborated by market data by correlation or other means. • Level 3 Inputs - Unobservable inputs for determining the fair values of assets or liabilities that reflect an entity’s own assumptions about the assumptions that market participants would use in pricing the assets or liabilities. In general, fair value is based upon quoted market prices, where available. If such quoted market prices are not available, fair value is based upon internally developed models that primarily use, as inputs, observable market-based parameters. Valuation adjustments may be made to ensure that financial instruments are recorded at fair value. These adjustments may include amounts to reflect counterparty credit quality and our creditworthiness, among other things, as well as unobservable parameters. Any such valuation adjustments are applied consistently over time. Our valuation methodologies may produce a fair value calculation that may not be indicative of net realizable value or reflective of future fair values. While management believes our valuation methodologies are appropriate and consistent with other market participants, the use of different methodologies or assumptions to determine the fair value of certain financial instruments could result in a different estimate of fair value at the reporting date. Furthermore, the reported fair value amounts have not been comprehensively revalued since the presentation dates, and therefore, estimates of fair value after the balance sheet date may differ significantly from the amounts presented herein. A more detailed description of the valuation methodologies used for assets and liabilities measured at fair value is set forth below. Transfers between levels of the fair value hierarchy are recognized on the actual date of the event or circumstances that caused the transfer, which generally coincides with our monthly and/or quarterly valuation process. Financial Assets and Financial Liabilities: Financial assets and financial liabilities measured at fair value on a recurring basis include the following: Securities Available for Sale . U.S. Treasury securities are reported at fair value utilizing Level 1 inputs. Other securities classified as available for sale are reported at fair value utilizing Level 2 inputs. For these securities, we obtain fair value measurements from an independent pricing service. The fair value measurements consider observable data that may include dealer quotes, market spreads, cash flows, the U.S. Treasury yield curve, live trading levels, trade execution data, market consensus prepayment speeds, credit information and the bond’s terms and conditions, among other things. We review the prices supplied by the independent pricing service, as well as their underlying pricing methodologies, for reasonableness and to ensure such prices are aligned with traditional pricing matrices. In general, we do not purchase investment portfolio securities that are esoteric or that have a complicated structure. Our entire portfolio consists of traditional investments, nearly all of which are U.S. Treasury obligations, federal agency bullet or mortgage pass-through securities, or general obligation or revenue based municipal bonds. Pricing for such instruments is fairly generic and is easily obtained. From time to time, we will validate prices supplied by the independent pricing service by comparison to prices obtained from third-party sources or derived using internal models. Trading Securities . U.S. Treasury securities and exchange-listed common stock are reported at fair value utilizing Level 1 inputs. Other securities classified as trading are reported at fair value utilizing Level 2 inputs in the same manner as described above for securities available for sale. Derivatives . Derivatives are generally reported at fair value utilizing Level 2 inputs, except for foreign currency contracts, which are reported at fair value utilizing Level 1 inputs. We obtain dealer quotations and utilize internally developed valuation models to value commodity swaps/options. We utilize internally developed valuation models and/or third-party models with observable market data inputs to validate the valuations provided by the dealers. Though there has never been a significant discrepancy in the valuations, should such a significant discrepancy arise, we would obtain price verification from a third-party dealer. We utilize internal valuation methods with observable market data inputs to estimate fair values of customer interest rate swaps, caps and floors. We also obtain dealer quotations for these derivatives for comparative purposes to assess the reasonableness of the model valuations. In cases where significant credit valuation adjustments are incorporated into the estimation of fair value, reported amounts are considered to have been derived utilizing Level 3 inputs. For purposes of potential valuation adjustments to our derivative positions, we evaluate the credit risk of our counterparties as well as ours. Accordingly, we have considered factors such as the likelihood of our default and the default of our counterparties, our net exposures and remaining contractual life, among other things, in determining if any fair value adjustments related to credit risk are required. Counterparty exposure is evaluated by netting positions that are subject to master netting arrangements, as well as considering the amount of collateral securing the position. We review our counterparty exposure on a regular basis, and, when necessary, appropriate business actions are taken to adjust the exposure. We also utilize this approach to estimate our own credit risk on derivative liability positions. To date, we have not realized any significant losses due to a counterparty’s inability to pay any net uncollateralized position. The change in value of derivative assets and derivative liabilities attributable to credit risk was not significant during the reported periods. Non-Financial Assets and Non-Financial Liabilities: We do not have any non-financial assets or non-financial liabilities measured at fair value on a recurring basis. From time to time, non-financial assets measured at fair value on a non-recurring basis may include certain foreclosed assets which, upon initial recognition, were remeasured and reported at fair value through a charge-off to the allowance for loan losses and certain foreclosed assets which, subsequent to their initial recognition, were remeasured at fair value through a write-down included in other non-interest expense. Such fair value measurements were not significant during the reported periods. Charge-offs recognized upon loan foreclosures are generally offset by general or specific allocations of the allowance for credit losses on loans and generally do not, and did not during the reported periods, significantly impact our credit loss expense. Regulatory guidelines require us to reevaluate the fair value of other real estate owned on at least an annual basis. While our policy is to comply with the regulatory guidelines, our general practice is to reevaluate the fair value of collateral supporting impaired collateral dependent loans on a quarterly basis. Thus, appraisals are generally not considered to be outdated, and we typically do not make any adjustments to the appraised values. ASC Topic 825, “Financial Instruments,” requires disclosure of the fair value of financial assets and financial liabilities, including those financial assets and financial liabilities that are not measured and reported at fair value on a recurring basis or non-recurring basis. The estimated fair value approximates carrying value for cash and cash equivalents, accrued interest and the cash surrender value of life insurance policies. The methodologies for other financial assets and financial liabilities that are not measured and reported at fair value on a recurring basis or non-recurring basis are discussed below: Loans . The estimated fair value approximates carrying value for variable-rate loans that reprice frequently and with no significant change in credit risk. The fair value of fixed-rate loans and variable-rate loans which reprice on an infrequent basis is estimated by discounting future cash flows using the current interest rates at which similar loans with similar terms would be made to borrowers of similar credit quality. An overall valuation adjustment is made for specific credit risks as well as general portfolio credit risk. Deposits . The estimated fair value approximates carrying value for demand deposits. The fair value of fixed-rate deposit liabilities with defined maturities is estimated by discounting future cash flows using the interest rates currently offered for deposits of similar remaining maturities. The estimated fair value of deposits does not take into account the value of our long-term relationships with depositors, commonly known as core deposit intangibles, which are separate intangible assets, and not considered financial instruments. Nonetheless, we would likely realize a core deposit premium if our deposit portfolio were sold in the principal market for such deposits. Borrowed Funds . The estimated fair value approximates carrying value for short-term borrowings. The fair value of long-term fixed-rate borrowings is estimated using quoted market prices, if available, or by discounting future cash flows using current interest rates for similar financial instruments. The estimated fair value approximates carrying value for variable-rate junior subordinated deferrable interest debentures that reprice quarterly. Loan Commitments, Standby and Commercial Letters of Credit . Our lending commitments have variable interest rates and “escape” clauses if the customer’s credit quality deteriorates. Therefore, the fair values of these items are not significant and are not included in the following table.
Transfers of Financial Assets	Transfers of Financial Assets . Transfers of financial assets are accounted for as sales when control over the assets has been surrendered. Control over transferred assets is deemed to be surrendered when (i) the assets have been isolated from us, (ii) the transferee obtains the right (free of conditions that constrain it from taking advantage of that right) to pledge or exchange the transferred assets, and (iii) we do not maintain effective control over the transferred assets through an agreement to repurchase them before their maturity.
Loss Contingencies	Loss Contingencies . Loss contingencies, including claims and legal actions arising in the ordinary course of business are recorded as liabilities when the likelihood of loss is probable and an amount or range of loss can be reasonably estimated.
Trust Assets	Trust Assets. Assets of our trust department, other than cash on deposit at Frost Bank, are not included in the accompanying financial statements because they are not our assets.
Reclassification, Comparability Adjustment	Certain items in prior financial statements have been reclassified to conform to the current presentation.
Accounting Changes, Reclassifications and Restatement	Accounting Changes, Reclassifications and Restatements. Certain items in prior financial statements have been reclassified to conform to the current presentation. As discussed above, on January 1, 2020 we adopted the provisions of ASC 326 using the modified retrospective method for all financial assets measured at amortized cost and off-balance-sheet credit exposures. Upon adoption, we recognized an after-tax cumulative effect reduction to retained earnings totaling $29.3 million, as detailed in the table below. The following table details the impact of the adoption of ASC 326 on the allowance for credit losses as of January 1, 2020. January 1, 2020 Pre-Adoption Allowance Impact of Adoption Post-Adoption Allowance Cumulative Effect on Retained Earnings Securities held to maturity: U.S. Treasury $ — $ — $ — $ — Residential mortgage-backed securities — — — — States and political subdivisions — 215 215 (170) Other — — — — Total $ — $ 215 $ 215 $ (170) Loans: Commercial and industrial $ 51,593 $ 21,263 $ 72,856 $ (16,798) Energy 37,382 (10,453) 26,929 8,258 Commercial real estate 31,037 (13,519) 17,518 10,680 Consumer real estate 4,113 2,392 6,505 (1,890) Consumer and other 8,042 (2,248) 5,794 1,776 Total $ 132,167 $ (2,565) $ 129,602 $ 2,026 Off-balance-sheet credit exposures $ 500 $ 39,377 $ 39,877 $ (31,108)

Receivables, Loans, Notes Recei

Receivables, Loans, Notes Receivable, and Others (Policies)	12 Months Ended
Receivables, Loans, Notes Receivable, and Others (Policies)	Dec. 31, 2022
Receivables [Abstract]
Allowance for Credit Losses Loans	Allowance for Credit Losses - Loans: The allowance for credit losses on loans is a contra-asset valuation account, calculated in accordance with ASC 326, that is deducted from the amortized cost basis of loans to present management's best estimate of the net amount expected to be collected. Loans are charged-off against the allowance when deemed uncollectible by management. Expected recoveries do not exceed the aggregate of amounts previously charged-off and expected to be charged-off. Adjustments to the allowance are reported in our income statement as a component of credit loss expense. Management has made the accounting policy election to exclude accrued interest receivable on loans from the estimate of credit losses. Further information regarding our policies and methodology used to estimate the allowance for credit losses on loans is presented in Note 3 - Loans. Allowance For Credit Losses - Loans. The allowance for credit losses on loans is a contra-asset valuation account, calculated in accordance with ASC 326, that is deducted from the amortized cost basis of loans to present the net amount expected to be collected. The amount of the allowance represents management's best estimate of current expected credit losses on loans considering available information, from internal and external sources, relevant to assessing collectibility over the loans' contractual terms, adjusted for expected prepayments when appropriate. The contractual term excludes expected extensions, renewals and modifications unless (i) management has a reasonable expectation that a loan to an individual borrower that is experiencing financial difficulty will be modified or (ii) such extension or renewal options are not unconditionally cancellable by us and, in such cases, the borrower is likely to meet applicable conditions and likely to request extension or renewal. Relevant available information includes historical credit loss experience, current conditions and reasonable and supportable forecasts. While historical credit loss experience provides the basis for the estimation of expected credit losses, adjustments to historical loss information may be made for differences in current portfolio-specific risk characteristics, environmental conditions or other relevant factors. The allowance for credit losses is measured on a collective basis for portfolios of loans when similar risk characteristics exist. Loans that do not share risk characteristics are evaluated for expected credit losses on an individual basis and excluded from the collective evaluation. Expected credit losses for collateral dependent loans, including loans where the borrower is experiencing financial difficulty but foreclosure is not probable, are based on the fair value of the collateral at the reporting date, adjusted for selling costs as appropriate. Credit loss expense related to loans reflects the totality of actions taken on all loans for a particular period including any necessary increases or decreases in the allowance related to changes in credit loss expectations associated with specific loans or pools of loans. Portions of the allowance may be allocated for specific credits; however, the entire allowance is available for any credit that, in management’s judgment, should be charged off. While management utilizes its best judgment and information available, the ultimate appropriateness of the allowance is dependent upon a variety of factors beyond our control, including the performance of our loan portfolio, the economy, changes in interest rates and the view of the regulatory authorities toward loan classifications. In calculating the allowance for credit losses, most loans are segmented into pools based upon similar characteristics and risk profiles. Common characteristics and risk profiles include the type/purpose of loan, underlying collateral, geographical similarity and historical/expected credit loss patterns. In developing these loan pools for the purposes of modeling expected credit losses, we also analyzed the degree of correlation in how loans within each portfolio respond when subjected to varying economic conditions and scenarios as well as other portfolio stress factors. For modeling purposes, our loan pools include (i) commercial and industrial and energy - non-revolving, (ii) commercial and industrial and energy - revolving, (iii) commercial real estate - owner occupied, (iv) commercial real estate - non-owner occupied, (v) commercial real estate - construction/land development, (vi) consumer real estate and (vii) consumer and other. We periodically reassess each pool to ensure the loans within the pool continue to share similar characteristics and risk profiles and to determine whether further segmentation is necessary. For each loan pool, we measure expected credit losses over the life of each loan utilizing a combination of models which measure (i) probability of default (“PD”), which is the likelihood that loan will stop performing/default, (ii) probability of attrition (“PA”), which is the likelihood that a loan will pay-off prior to maturity, (iii) loss given default (“LGD”), which is the expected loss rate for loans in default and (iv) exposure at default (“EAD”), which is the estimated outstanding principal balance of the loans upon default, including the expected funding of unfunded commitments outstanding as of the measurement date. For certain commercial loan portfolios, the PD is calculated using a transition matrix to determine the likelihood of a customer’s risk grade migrating from one specified range of risk grades to a different specified range. Expected credit losses are calculated as the product of PD (adjusted for attrition), LGD and EAD. This methodology builds on default probabilities already incorporated into our risk grading process by utilizing pool-specific historical loss rates to calculate expected credit losses. These pool-specific historical loss rates may be adjusted for current macroeconomic assumptions, as further discussed below, and other factors such as differences in underwriting standards, portfolio mix, or when historical asset terms do not reflect the contractual terms of the financial assets being evaluated as of the measurement date. Each time we measure expected credit losses, we assess the relevancy of historical loss information and consider any necessary adjustments to address any differences in asset-specific characteristics. Due to their short-term nature, expected credit losses for overdrafts included in consumer and other loans are based solely upon a weighting of recent historical charge-offs over a period of three years. The measurement of expected credit losses is impacted by loan/borrower attributes and certain macroeconomic variables. Significant loan/borrower attributes utilized in our modeling processes include, among other things, (i) origination date, (ii) maturity date, (iii) payment type, (iv) collateral type and amount, (v) current risk grade, (vi) current unpaid balance and commitment utilization rate, (vii) payment status/delinquency history and (viii) expected recoveries of previously charged-off amounts. Significant macroeconomic variables utilized in our modeling processes include, among other things, (i) Gross State Product for Texas and U.S. Gross Domestic Product, (ii) selected market interest rates including U.S. Treasury rates, bank prime rate, 30-year fixed mortgage rate, BBB corporate bond rate, among others, (iii) unemployment rates, (iv) commercial and residential property prices in Texas and the U.S. as a whole, (v) West Texas Intermediate crude oil price and (vi) total stock market index. PD and PA were estimated by analyzing internally-sourced data related to historical performance of each loan pool over a complete economic cycle. PD and PA are adjusted to reflect the current impact of certain macroeconomic variables as well as their expected changes over a reasonable and supportable forecast period. We have determined that we are reasonably able to forecast the macroeconomic variables used in our modeling processes with an acceptable degree of confidence for a total of two years with the last twelve months of the forecast period encompassing a reversion process whereby the forecasted macroeconomic variables are reverted to their historical mean utilizing a rational, systematic basis. The macroeconomic variables utilized as inputs in our modeling processes were subjected to a variety of analysis procedures and were selected primarily based on statistical relevancy and correlation to our historical credit losses. By reverting these modeling inputs to their historical mean and considering loan/borrower specific attributes, our models are intended to yield a measurement of expected credit losses that reflects our average historical loss rates for periods subsequent to the twelve-month reversion period. The LGD is based on historical recovery averages for each loan pool, adjusted to reflect the current impact of certain macroeconomic variables as well as their expected changes over a two-year forecast period, with the final twelve months of the forecast period encompassing a reversion process, which management considers to be both reasonable and supportable. This same forecast/reversion period is used for all macroeconomic variables used in all of our models. EAD is estimated using a linear regression model that estimates the average percentage of the loan balance that remains at the time of a default event. Management qualitatively adjusts model results for risk factors that are not considered within our modeling processes but are nonetheless relevant in assessing the expected credit losses within our loan pools. These qualitative factor (“Q-Factor”) and other qualitative adjustments may increase or decrease management's estimate of expected credit losses by a calculated percentage or amount based upon the estimated level of risk. The various risks that may be considered in making Q-Factor and other qualitative adjustments include, among other things, the impact of (i) changes in lending policies and procedures, including changes in underwriting standards and practices for collections, write-offs, and recoveries, (ii) actual and expected changes in international, national, regional, and local economic and business conditions and developments that affect the collectibility of the loan pools, (iii) changes in the nature and volume of the loan pools and in the terms of the underlying loans, (iv) changes in the experience, ability, and depth of our lending management and staff, (v) changes in volume and severity of past due financial assets, the volume of non-accrual assets, and the volume and severity of adversely classified or graded assets, (vi) changes in the quality of our credit review function, (vii) changes in the value of the underlying collateral for loans that are non-collateral dependent, (viii) the existence, growth, and effect of any concentrations of credit and (ix) other factors such as the regulatory, legal and technological environments; competition; and events such as natural disasters or health pandemics. In some cases, management may determine that an individual loan exhibits unique risk characteristics which differentiate the loan from other loans within our loan pools. In such cases, the loans are evaluated for expected credit losses on an individual basis and excluded from the collective evaluation. Specific allocations of the allowance for credit losses are determined by analyzing the borrower’s ability to repay amounts owed, collateral deficiencies, the relative risk grade of the loan and economic conditions affecting the borrower’s industry, among other things. A loan is considered to be collateral dependent when, based upon management's assessment, the borrower is experiencing financial difficulty and repayment is expected to be provided substantially through the operation or sale of the collateral. In such cases, expected credit losses are based on the fair value of the collateral at

Fair Value Measures and Disclos

Fair Value Measures and Disclosures (Policies)	12 Months Ended
Fair Value Measures and Disclosures (Policies)	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Off-Balance-Sheet Credit Exposure	Allowance For Credit Losses - Off-Balance-Sheet Credit Exposures: The allowance for credit losses on off-balance-sheet credit exposures is a liability account, calculated in accordance with ASC 326, representing expected credit losses over the contractual period for which we are exposed to credit risk resulting from a contractual obligation to extend credit. No allowance is recognized if we have the unconditional right to cancel the obligation. The allowance is reported as a component of accrued interest payable and other liabilities in our consolidated balance sheets. Adjustments to the allowance are reported in our income statement as a component of credit loss expense. Further information regarding our policies and methodology used to estimate the allowance for credit Allowance For Credit Losses - Off-Balance-Sheet Credit Exposures. The allowance for credit losses on off-balance-sheet credit exposures is a liability account, calculated in accordance with ASC 326, representing expected credit losses over the contractual period for which we are exposed to credit risk resulting from a contractual obligation to extend credit. No allowance is recognized if we have the unconditional right to cancel the obligation. Off-balance-sheet credit exposures primarily consist of amounts available under outstanding lines of credit and letters of credit detailed in the table above. For the period of exposure, the estimate of expected credit losses considers both the likelihood that funding will occur and the amount expected to be funded over the estimated remaining life of the commitment or other off-balance-sheet exposure. The likelihood and expected amount of funding are based on historical utilization rates. The amount of the allowance represents management's best estimate of expected credit losses on commitments expected to be funded over the contractual life of the commitment. Estimating credit losses on amounts expected to be funded uses the same methodology as described for loans in Note 3 - Loans as if such commitments were funded.

Earnings Per Share (Policies)

Earnings Per Share (Policies)	12 Months Ended
Earnings Per Share (Policies)	Dec. 31, 2022
Earnings Per Share [Abstract]
Basic and Diluted Earnings Per Common Share	Basic and Diluted Earnings Per Common Share. Earnings per common share is computed using the two-class method prescribed under ASC Topic 260, “Earnings Per Share.” ASC 260 provides that unvested share-based payment awards that contain nonforfeitable rights to dividends or dividend equivalents (whether paid or unpaid) are participating securities and shall be included in the computation of earnings per share pursuant to the two-class method. We have determined that our outstanding non-vested stock awards/stock units and deferred stock units are participating securities. Earnings Per Common Share . Earnings per common share is computed using the two-class method. Basic earnings per common share is computed by dividing net earnings allocated to common stock by the weighted-average number of common shares outstanding during the applicable period, excluding outstanding participating securities. Participating securities include non-vested stock awards/stock units, deferred stock units and performance stock units (during the performance period), though no actual shares of common stock related to any type of stock unit have been issued. Non-vested stock awards/stock units and deferred stock units are considered participating securities because holders of these securities receive non-forfeitable dividends at the same rate as holders of our common stock. Holders of performance stock units receive dividend equivalent payments for dividends paid during the performance period at the vesting date of the award based upon the number of units that ultimately vest. Diluted earnings per common share is computed using the weighted-average number of shares determined for the basic earnings per common share computation plus the dilutive effect of stock compensation using the treasury stock method.

Compensation Related Costs, Pos

Compensation Related Costs, Postemployment Benefits (Policies)	12 Months Ended
	Dec. 31, 2022
Postemployment Benefits [Abstract]
Stock Based Compensation	Share-Based Payments . Compensation expense for stock options, non-vested stock awards/stock units and deferred stock units is based on the fair value of the award on the measurement date, which, for us, is the date of the grant and is recognized ratably over the service period of the award. Compensation expense for performance stock units is based on the fair value of the award on the measurement date, which, for us, is the date of the grant and is recognized over the service period of the award based upon the probable number of units expected to vest. The fair value of stock options is estimated using a binomial lattice-based valuation model. The fair value of non-vested stock awards/stock units and deferred stock units is generally the market price of our stock on the date of grant. The fair value of performance stock units is generally the market price of our stock on the date of grant discounted by the present value of the dividends expected to be paid on our common stock during the service period of the award because dividend equivalent payments on performance stock units are deferred until such time that the units vest and shares are issued. The impact of forfeitures of share-based payment awards on compensation expense is recognized as forfeitures occur. We have three active stock compensation plans (the 2005 Omnibus Incentive Plan, the 2007 Outside Directors Incentive Plan and the 2015 Omnibus Incentive Plan). All of the plans have been approved by our shareholders. During 2015, the 2015 Omnibus Incentive Plan (“2015 Plan”) was established to replace both the 2005 Omnibus Incentive Plan (“2005 Plan”) and the 2007 Outside Directors Incentive Plan (the “2007 Directors Plan”). All remaining shares authorized for grant under the superseded 2005 Plan and 2007 Directors Plan were transferred to the 2015 Plan. Our stock compensation plans were established to (i) motivate superior performance by means of performance-related incentives, (ii) encourage and provide for the acquisition of an ownership interest in our company by employees and non-employee directors and (iii) enable us to attract and retain qualified and competent persons as employees and to serve as members of our board of directors. Under the 2015 Plan, we may grant, among other things, nonqualified stock options, incentive stock options, stock awards, stock appreciation rights, restricted stock units, performance share units or any combination thereof to certain employees and non-employee directors. Any of the authorized shares may be used for any type of award Options awarded to employees generally have a ten four three four Performance stock units represent shares potentially issuable in the future. For performance stock units granted in 2022 and 2021, issuance is based upon the measure of our achievement of growth in adjusted net revenue, averaged over the three-year performance period, compared to the 2022 and 2021 base-year amounts, respectively. Adjusted net revenue for each three-year performance period is calculated as the sum of taxable-equivalent net interest income (excluding the effects of PPP lending) and non-interest income, reduced by non-interest expense (excluding the effects of PPP lending) and net charge-offs. The 2022 and 2021 base-year adjusted net revenue amounts of approximately $713.8 million and $415.9 million, respectively, were calculated as the sum of taxable-equivalent net interest income (excluding the effects of PPP lending) and non-interest income, reduced by non-interest expense (excluding the effects of PPP lending) and the product of average total loans (excluding PPP loans) and 0.30%. The ultimate number of shares issuable under each performance award is the product of the award target and the award payout percentage for the given level of achievement. The level of achievement is measured as the amount by which adjusted net revenue, averaged over a three-year performance period, exceeds the 2022 and 2021 base-year amounts, as applicable, stated as an average growth percentage. The award payout percentages by level of achievement for both the 2022 and 2021 awards are as follows: (i) less than 13% average growth pays out at 0% of target, (ii) 13% average growth pays out at 50% of target, (iii) 19% average growth pays out at 100% of target and (iv) 25% average growth or more pays out at 150% of target. Achievement between the aforementioned average growth percentages will result in an award payout percentage determined based on straight-line interpolation between the percentages. For performance stock units granted prior to 2021, issuance is based upon the measure of our achievement of relative return on assets over a three-year performance period compared to an identified peer group's achievement of relative return on assets over the same three-year performance period. The ultimate number of shares issuable under each performance award is the product of the award target and the award payout percentage for the given level of achievement. The level of achievement is measured as the percentile rank of relative return on assets among the peer group. The award payout percentages by level of achievement are as follows: (i) less than 25th percentile pays out at 0% of target, (ii) 25th percentile pays out at 50% of target, (iii) 50th percentile pays out at 100% of target and (iv) 75th percentile or more pays out at 150% of target. Achievement between the aforementioned percentiles will result in an award payout percentage determined based on straight-line interpolation between the percentiles. Performance stock units are eligible to receive equivalent dividend payments as such dividends are declared on our common stock during the performance period. Equivalent dividend payments are based upon the ultimate number of shares issued under each performance award and are deferred until such time that the units vest and shares are issued. Valuation of Stock-Based Compensation . For the purposes of recognizing stock-based compensation expense, the fair value of non-vested stock awards/stock units and deferred stock units is generally the market price of the stock on the measurement date, which, for us, is the date of the award. The fair value of performance stock units is determined in a similar manner except that the market price of the stock on the measurement date is discounted by the present value of the dividends expected to be paid on our common stock during the service period of the award because dividend equivalent payments on performance stock units are deferred until such time that the units vest and shares are issued. In applying this discount to the market price of our stock on the measurement date, we assumed we would pay a flat quarterly dividend during the service period equal to our most recent dividend payment, which was $0.87, $0.75 and $0.72 in 2022, 2021 and 2020, respectively, discounted at a weighted-average risk-free rate of 4.45%, 0.77% and 0.19% in 2022, 2021 and 2020, respectively.

Fair Value Measures and Discl_2

Fair Value Measures and Disclosures (Policies)	12 Months Ended
Fair Value Measures and Disclosures (Policies)	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements . In general, fair values of financial instruments are based upon quoted market prices, where available. If such quoted market prices are not available, fair value is based upon internally developed models that primarily use, as inputs, observable market-based parameters. Valuation adjustments may be made to ensure that financial instruments are recorded at fair value. These adjustments may include amounts to reflect counterparty credit quality and our creditworthiness, among other things, as well as unobservable parameters. Any such valuation adjustments are applied consistently over time. See Note 17 - Fair Value Measurements. The fair value of an asset or liability is the price that would be received to sell that asset or paid to transfer that liability in an orderly transaction occurring in the principal market (or most advantageous market in the absence of a principal market) for such asset or liability. In estimating fair value, we utilize valuation techniques that are consistent with the market approach, the income approach and/or the cost approach. Such valuation techniques are consistently applied. Inputs to valuation techniques include the assumptions that market participants would use in pricing an asset or liability. ASC Topic 820 establishes a fair value hierarchy for valuation inputs that gives the highest priority to quoted prices in active markets for identical assets or liabilities and the lowest priority to unobservable inputs. The fair value hierarchy is as follows: • Level 1 Inputs - Unadjusted quoted prices in active markets for identical assets or liabilities that the reporting entity has the ability to access at the measurement date. • Level 2 Inputs - Inputs other than quoted prices included in Level 1 that are observable for the asset or liability, either directly or indirectly. These might include quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable for the asset or liability (such as interest rates, volatilities, prepayment speeds, credit risks, etc.) or inputs that are derived principally from or corroborated by market data by correlation or other means. • Level 3 Inputs - Unobservable inputs for determining the fair values of assets or liabilities that reflect an entity’s own assumptions about the assumptions that market participants would use in pricing the assets or liabilities. In general, fair value is based upon quoted market prices, where available. If such quoted market prices are not available, fair value is based upon internally developed models that primarily use, as inputs, observable market-based parameters. Valuation adjustments may be made to ensure that financial instruments are recorded at fair value. These adjustments may include amounts to reflect counterparty credit quality and our creditworthiness, among other things, as well as unobservable parameters. Any such valuation adjustments are applied consistently over time. Our valuation methodologies may produce a fair value calculation that may not be indicative of net realizable value or reflective of future fair values. While management believes our valuation methodologies are appropriate and consistent with other market participants, the use of different methodologies or assumptions to determine the fair value of certain financial instruments could result in a different estimate of fair value at the reporting date. Furthermore, the reported fair value amounts have not been comprehensively revalued since the presentation dates, and therefore, estimates of fair value after the balance sheet date may differ significantly from the amounts presented herein. A more detailed description of the valuation methodologies used for assets and liabilities measured at fair value is set forth below. Transfers between levels of the fair value hierarchy are recognized on the actual date of the event or circumstances that caused the transfer, which generally coincides with our monthly and/or quarterly valuation process. Financial Assets and Financial Liabilities: Financial assets and financial liabilities measured at fair value on a recurring basis include the following: Securities Available for Sale . U.S. Treasury securities are reported at fair value utilizing Level 1 inputs. Other securities classified as available for sale are reported at fair value utilizing Level 2 inputs. For these securities, we obtain fair value measurements from an independent pricing service. The fair value measurements consider observable data that may include dealer quotes, market spreads, cash flows, the U.S. Treasury yield curve, live trading levels, trade execution data, market consensus prepayment speeds, credit information and the bond’s terms and conditions, among other things. We review the prices supplied by the independent pricing service, as well as their underlying pricing methodologies, for reasonableness and to ensure such prices are aligned with traditional pricing matrices. In general, we do not purchase investment portfolio securities that are esoteric or that have a complicated structure. Our entire portfolio consists of traditional investments, nearly all of which are U.S. Treasury obligations, federal agency bullet or mortgage pass-through securities, or general obligation or revenue based municipal bonds. Pricing for such instruments is fairly generic and is easily obtained. From time to time, we will validate prices supplied by the independent pricing service by comparison to prices obtained from third-party sources or derived using internal models. Trading Securities . U.S. Treasury securities and exchange-listed common stock are reported at fair value utilizing Level 1 inputs. Other securities classified as trading are reported at fair value utilizing Level 2 inputs in the same manner as described above for securities available for sale. Derivatives . Derivatives are generally reported at fair value utilizing Level 2 inputs, except for foreign currency contracts, which are reported at fair value utilizing Level 1 inputs. We obtain dealer quotations and utilize internally developed valuation models to value commodity swaps/options. We utilize internally developed valuation models and/or third-party models with observable market data inputs to validate the valuations provided by the dealers. Though there has never been a significant discrepancy in the valuations, should such a significant discrepancy arise, we would obtain price verification from a third-party dealer. We utilize internal valuation methods with observable market data inputs to estimate fair values of customer interest rate swaps, caps and floors. We also obtain dealer quotations for these derivatives for comparative purposes to assess the reasonableness of the model valuations. In cases where significant credit valuation adjustments are incorporated into the estimation of fair value, reported amounts are considered to have been derived utilizing Level 3 inputs. For purposes of potential valuation adjustments to our derivative positions, we evaluate the credit risk of our counterparties as well as ours. Accordingly, we have considered factors such as the likelihood of our default and the default of our counterparties, our net exposures and remaining contractual life, among other things, in determining if any fair value adjustments related to credit risk are required. Counterparty exposure is evaluated by netting positions that are subject to master netting arrangements, as well as considering the amount of collateral securing the position. We review our counterparty exposure on a regular basis, and, when necessary, appropriate business actions are taken to adjust the exposure. We also utilize this approach to estimate our own credit risk on derivative liability positions. To date, we have not realized any significant losses due to a counterparty’s inability to pay any net uncollateralized position. The change in value of derivative assets and derivative liabilities attributable to credit risk was not significant during the reported periods. Non-Financial Assets and Non-Financial Liabilities: We do not have any non-financial assets or non-financial liabilities measured at fair value on a recurring basis. From time to time, non-financial assets measured at fair value on a non-recurring basis may include certain foreclosed assets which, upon initial recognition, were remeasured and reported at fair value through a charge-off to the allowance for loan losses and certain foreclosed assets which, subsequent to their initial recognition, were remeasured at fair value through a write-down included in other non-interest expense. Such fair value measurements were not significant during the reported periods. Charge-offs recognized upon loan foreclosures are generally offset by general or specific allocations of the allowance for credit losses on loans and generally do not, and did not during the reported periods, significantly impact our credit loss expense. Regulatory guidelines require us to reevaluate the fair value of other real estate owned on at least an annual basis. While our policy is to comply with the regulatory guidelines, our general practice is to reevaluate the fair value of collateral supporting impaired collateral dependent loans on a quarterly basis. Thus, appraisals are generally not considered to be outdated, and we typically do not make any adjustments to the appraised values. ASC Topic 825, “Financial Instruments,” requires disclosure of the fair value of financial assets and financial liabilities, including those financial assets and financial liabilities that are not measured and reported at fair value on a recurring basis or non-recurring basis. The estimated fair value approximates carrying value for cash and cash equivalents, accrued interest and the cash surrender value of life insurance policies. The methodologies for other financial assets and financial liabilities that are not measured and reported at fair value on a recurring basis or non-recurring basis are discussed below: Loans . The estimated fair value approximates carrying value for variable-rate loans that reprice frequently and with no significant change in credit risk. The fair value of fixed-rate loans and variable-rate loans which reprice on an infrequent basis is estimated by discounting future cash flows using the current interest rates at which similar loans with similar terms would be made to borrowers of similar credit quality. An overall valuation adjustment is made for specific credit risks as well as general portfolio credit risk. Deposits . The estimated fair value approximates carrying value for demand deposits. The fair value of fixed-rate deposit liabilities with defined maturities is estimated by discounting future cash flows using the interest rates currently offered for deposits of similar remaining maturities. The estimated fair value of deposits does not take into account the value of our long-term relationships with depositors, commonly known as core deposit intangibles, which are separate intangible assets, and not considered financial instruments. Nonetheless, we would likely realize a core deposit premium if our deposit portfolio were sold in the principal market for such deposits. Borrowed Funds . The estimated fair value approximates carrying value for short-term borrowings. The fair value of long-term fixed-rate borrowings is estimated using quoted market prices, if available, or by discounting future cash flows using current interest rates for similar financial instruments. The estimated fair value approximates carrying value for variable-rate junior subordinated deferrable interest debentures that reprice quarterly. Loan Commitments, Standby and Commercial Letters of Credit . Our lending commitments have variable interest rates and “escape” clauses if the customer’s credit quality deteriorates. Therefore, the fair values of these items are not significant and are not included in the following table.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
Summary of Significant Accounting Policies (Tables)	Dec. 31, 2022
Accounting Policies [Abstract]
Additional Cash Flow Information	Additional cash flow information was as follows: Year Ended December 31, 2022 2021 2020 Cash paid for interest $ 169,020 $ 29,003 $ 49,300 Cash paid for income tax 100,000 39,852 44,140 Significant non-cash transactions: Exchange of real estate — 11,036 — Unsettled securities transactions 94,884 27,032 57,783 Loans foreclosed and transferred to other real estate owned and foreclosed assets 239 3,464 140 Right-of-use lease assets obtained in exchange for lessee operating lease liabilities 31,787 12,854 18,284 Treasury stock issued to 401(k) stock purchase plan — 1,749 10,307
Accounting Standards Update and Change in Accounting Principle	The following table details the impact of the adoption of ASC 326 on the allowance for credit losses as of January 1, 2020. January 1, 2020 Pre-Adoption Allowance Impact of Adoption Post-Adoption Allowance Cumulative Effect on Retained Earnings Securities held to maturity: U.S. Treasury $ — $ — $ — $ — Residential mortgage-backed securities — — — — States and political subdivisions — 215 215 (170) Other — — — — Total $ — $ 215 $ 215 $ (170) Loans: Commercial and industrial $ 51,593 $ 21,263 $ 72,856 $ (16,798) Energy 37,382 (10,453) 26,929 8,258 Commercial real estate 31,037 (13,519) 17,518 10,680 Consumer real estate 4,113 2,392 6,505 (1,890) Consumer and other 8,042 (2,248) 5,794 1,776 Total $ 132,167 $ (2,565) $ 129,602 $ 2,026 Off-balance-sheet credit exposures $ 500 $ 39,377 $ 39,877 $ (31,108)

Securities (Tables)

Securities (Tables)	12 Months Ended
Securities (Tables)	Dec. 31, 2022
Investments, Debt and Equity Securities [Abstract]
Debt Securities, Held-to-maturity	A summary of the amortized cost, fair value and allowance for credit losses related to securities held to maturity as of December 31, 2022 and 2021 is presented below. Amortized Gross Gross Estimated Allowance Net December 31, 2022 Residential mortgage-backed securities $ 526,122 $ — $ 65,322 $ 460,800 $ — $ 526,122 States and political subdivisions 2,111,619 13,048 119,033 2,005,634 (158) 2,111,461 Other 1,500 — 69 1,431 — 1,500 Total $ 2,639,241 $ 13,048 $ 184,424 $ 2,467,865 $ (158) $ 2,639,083 December 31, 2021 Residential mortgage-backed securities $ 527,264 $ 18,766 $ — $ 546,030 $ — $ 527,264 States and political subdivisions 1,220,573 41,141 101 1,261,613 (158) 1,220,415 Other 1,500 — — 1,500 — 1,500 Total $ 1,749,337 $ 59,907 $ 101 $ 1,809,143 $ (158) $ 1,749,179
Moody's and Standard & Poor's Bond Ratings	The following table summarizes Moody's and/or Standard & Poor's bond ratings for our portfolio of held-to-maturity securities issued by States and political subdivisions and other securities as of December 31, 2022: States and Political Subdivisions Not Guaranteed or Pre-Refunded Guaranteed by the Texas PSF Pre-Refunded Total Other Aaa/AAA $ 273,201 $ 1,422,442 $ 121,961 $ 1,817,604 $ — Aa/AA 294,015 — — 294,015 — Not rated — — — — 1,500 Total $ 567,216 $ 1,422,442 $ 121,961 $ 2,111,619 $ 1,500
Debt Securities, Held-to-maturity, Allowance for Credit Loss	The following table details activity in the allowance for credit losses on held-to-maturity securities. 2022 2021 2020 Beginning balance $ 158 $ 160 $ — Impact of adopting ASC 326 — — 215 Credit loss expense (benefit) — (2) (55) Ending balance $ 158 $ 158 $ 160
Debt Securities, Available-for-sale	A summary of the amortized cost, fair value and allowance for credit losses related to securities available for sale as of December 31, 2022 and 2021 is presented below. Amortized Gross Gross Allowance Estimated December 31, 2022 U.S. Treasury $ 5,450,546 $ — $ 398,959 $ — $ 5,051,587 Residential mortgage-backed securities 7,316,824 8,050 948,638 — 6,376,236 States and political subdivisions 7,098,635 9,108 334,388 — 6,773,355 Other 42,427 — — — 42,427 Total $ 19,908,432 $ 17,158 $ 1,681,985 $ — $ 18,243,605 December 31, 2021 U.S. Treasury $ 2,165,702 $ 23,333 $ 9,602 $ — $ 2,179,433 Residential mortgage-backed securities 4,059,692 31,662 25,089 — 4,066,265 States and political subdivisions 7,178,135 463,810 5,374 — 7,636,571 Other 42,359 — — — 42,359 Total $ 13,445,888 $ 518,805 $ 40,065 $ — $ 13,924,628
Year End Securities with Unrealized Losses, Segregated by Length of Impairment	The table below summarizes, as of December 31, 2022, securities available for sale in an unrealized loss position for which an allowance for credit losses has not been recorded, aggregated by type of security and length of time in a continuous unrealized loss position. Less than 12 Months More than 12 Months Total Estimated Unrealized Estimated Unrealized Estimated Unrealized U.S. Treasury $ 2,012,129 $ 63,515 $ 3,039,458 $ 335,444 $ 5,051,587 $ 398,959 Residential mortgage-backed securities 3,265,658 345,307 2,495,906 603,331 5,761,564 948,638 States and political subdivisions 3,923,159 136,957 681,677 197,431 4,604,836 334,388 Total $ 9,200,946 $ 545,779 $ 6,217,041 $ 1,136,206 $ 15,417,987 $ 1,681,985
Amortized Cost and Estimated Fair Value of Securities, Excluding Trading Securities, Presented by Contractual Maturity	The following table summarizes the maturity distribution schedule of securities held to maturity and securities available for sale as of December 31, 2022. Mortgage-backed securities are included in maturity categories based on their stated maturity date. Expected maturities may differ from contractual maturities because issuers may have the right to call or prepay obligations. Other securities classified as available for sale include stock in the Federal Reserve Bank and the Federal Home Loan Bank, which have no maturity date. These securities have been included in the total column only. Within 1 Year 1 - 5 Years 5 - 10 Years After 10 Years Total Held To Maturity Amortized Cost Residential mortgage-backed securities $ — $ — $ 514,059 $ 12,063 $ 526,122 States and political subdivisions 123,591 24,339 8,297 1,955,392 2,111,619 Other — 1,500 — — 1,500 Total $ 123,591 $ 25,839 $ 522,356 $ 1,967,455 $ 2,639,241 Estimated Fair Value Residential mortgage-backed securities $ — $ — $ 450,961 $ 9,839 $ 460,800 States and political subdivisions 123,505 24,292 8,286 1,849,551 2,005,634 Other — 1,431 — — 1,431 Total $ 123,505 $ 25,723 $ 459,247 $ 1,859,390 $ 2,467,865 Available For Sale Amortized Cost U. S. Treasury $ 249,363 $ 3,574,630 $ 1,434,504 $ 192,049 $ 5,450,546 Residential mortgage-backed securities 8 7,729 16,025 7,293,062 7,316,824 States and political subdivisions 261,477 1,464,493 937,127 4,435,538 7,098,635 Other — — — — 42,427 Total $ 510,848 $ 5,046,852 $ 2,387,656 $ 11,920,649 $ 19,908,432 Estimated Fair Value U. S. Treasury $ 240,361 $ 3,424,023 $ 1,244,812 $ 142,391 $ 5,051,587 Residential mortgage-backed securities 8 7,527 15,892 6,352,809 6,376,236 States and political subdivisions 261,888 1,470,098 918,563 4,122,806 6,773,355 Other — — — — 42,427 Total $ 502,257 $ 4,901,648 $ 2,179,267 $ 10,618,006 $ 18,243,605
Schedule of Realized Gain (Loss)	Sales of securities available for sale were as follows: 2022 2021 2020 Proceeds from sales $ — $ 1,999,891 $ 1,162,352 Gross realized gains — 69 108,989 Gross realized losses — — — Tax benefit (expense) related to securities gains/losses — (14) (22,888)
Investment Income	Premium amortization and discount accretion included in interest income on securities was as follows: 2022 2021 2020 Premium amortization $ (110,997) $ (121,994) $ (126,210) Discount accretion 13,597 2,752 2,425 Net (premium amortization) discount accretion $ (97,400) $ (119,242) $ (123,785)
Year End Trading Account Securities, at Estimated Fair Value	Year-end trading account securities, at estimated fair value, were as follows: 2022 2021 U.S. Treasury $ 25,879 $ 24,237 States and political subdivisions 2,166 925 Total $ 28,045 $ 25,162
Net Gains and Losses on Trading Account Securities	Net gains and losses on trading account securities were as follows: 2022 2021 2020 Net gain on sales transactions $ 3,129 $ 1,014 $ 1,102 Net mark-to-market gains (losses) (230) (75) 85 Net gain on trading account securities $ 2,899 $ 939 $ 1,187

Loans (Tables)

Loans (Tables)	12 Months Ended
Loans (Tables)	Dec. 31, 2022
Receivables [Abstract]
Loans	Year-end loans, including leases net of unearned discounts, consisted of the following: 2022 2021 Commercial and industrial $ 5,674,798 $ 5,364,954 Energy: Production 696,570 878,436 Service 133,542 105,901 Other 95,617 93,455 Total energy 925,729 1,077,792 Paycheck Protection Program 34,852 428,882 Commercial real estate: Commercial mortgages 6,168,910 5,867,062 Construction 1,477,247 1,304,271 Land 537,168 405,277 Total commercial real estate 8,183,325 7,576,610 Consumer real estate: Home equity lines of credit 691,841 519,098 Home equity loans 449,507 324,157 Home improvement loans 577,377 428,069 Other 124,814 139,466 Total consumer real estate 1,843,539 1,410,790 Total real estate 10,026,864 8,987,400 Consumer and other 492,726 477,369 Total loans $ 17,154,969 $ 16,336,397
Activities in Related Party Loans	Activity in related party loans during 2022 is presented in the following table. Other changes were primarily related to changes in related-party status. Balance outstanding at December 31, 2021 $ 350,538 Principal additions 337,700 Principal payments (294,857) Other changes (2,126) Balance outstanding at December 31, 2022 $ 391,255
Non-Accrual Loans, Segregated by Class of Loans	Year-end non-accrual loans, segregated by class of loans, were as follows: December 31, 2022 December 31, 2021 Total Non-Accrual Non-Accrual with No Credit Loss Allowance Total Non-Accrual Non-Accrual with No Credit Loss Allowance Commercial and industrial $ 18,130 $ 8,514 $ 22,582 $ 4,701 Energy 15,224 7,139 14,433 8,533 Commercial real estate: Buildings, land and other 3,552 1,991 15,297 13,817 Construction — — 948 — Consumer real estate 927 927 440 138 Consumer and other — — 13 13 Total $ 37,833 $ 18,571 $ 53,713 $ 27,202
Financing Receivable, Non-Accrual Loans, Segregated by Class of Loan and Year of Origination	The following tables present non-accrual loans as of December 31, 2022 and December 31, 2021 by class and year of origination. December 31, 2022 2022 2021 2020 2019 2018 Prior Revolving Loans Revolving Loans Converted to Term Total Commercial and industrial $ — $ 1,252 $ 1,089 $ 3,242 $ 1,197 $ 191 $ 2,973 $ 8,186 $ 18,130 Energy 4,657 — 72 1,386 10 — 7,631 1,468 15,224 Commercial real estate: Buildings, land and other 1,644 — — 217 266 1,425 — — 3,552 Construction — — — — — — — — — Consumer real estate — 258 — — — 84 — 585 927 Consumer and other — — — — — — — — — Total $ 6,301 $ 1,510 $ 1,161 $ 4,845 $ 1,473 $ 1,700 $ 10,604 $ 10,239 $ 37,833 December 31, 2021 2021 2020 2019 2018 2017 Prior Revolving Loans Revolving Loans Converted to Term Total Commercial and industrial $ 636 $ 3,856 $ 5,047 $ 1,820 $ 765 $ 353 $ 4,635 $ 5,470 $ 22,582 Energy — — 5,358 1,325 — — 6,931 819 14,433 Commercial real estate: Buildings, land and other 6,038 307 3,446 814 2,030 2,662 — — 15,297 Construction — 948 — — — — — — 948 Consumer real estate — — — — — 408 — 32 440 Consumer and other 13 — — — — — — — 13 Total $ 6,687 $ 5,111 $ 13,851 $ 3,959 $ 2,795 $ 3,423 $ 11,566 $ 6,321 $ 53,713
Age Analysis of Past Due Loans, Segregated by Class of Loans	An age analysis of past due loans (including both accruing and non-accruing loans), segregated by class of loans, as of December 31, 2022 is presented in the following table. Despite their past due status, Paycheck Protection Plan loans are fully guaranteed by the SBA. Loans Loans Total Past Current Total Loans Accruing Commercial and industrial $ 36,167 $ 12,853 $ 49,020 $ 5,625,778 $ 5,674,798 $ 5,560 Energy 2,880 7,680 10,560 915,169 925,729 — Paycheck Protection Program 5,321 13,867 19,188 15,664 34,852 13,867 Commercial real estate: Buildings, land and other 23,561 5,869 29,430 6,676,648 6,706,078 5,664 Construction — — — 1,477,247 1,477,247 — Consumer real estate 7,856 2,690 10,546 1,832,993 1,843,539 2,398 Consumer and other 5,155 311 5,466 487,260 492,726 311 Total $ 80,940 $ 43,270 $ 124,210 $ 17,030,759 $ 17,154,969 $ 27,800
Troubled Debt Restructurings	Troubled debt restructurings that occurred during 2022, 2021 and 2020 are set forth in the following table. 2022 2021 2020 Balance at Balance at Balance at Balance at Balance at Balance at Commercial and industrial $ — $ — $ 1,312 $ 1,162 $ 3,661 $ 192 Energy — — 3,817 721 2,432 2,421 Commercial real estate: Buildings, land and other 1,155 1,051 1,888 1,862 9,310 4,922 Construction — — — — 1,017 1,017 Consumer real estate — — — — — — Consumer and other — — — — 1,104 — $ 1,155 $ 1,051 $ 7,017 $ 3,745 $ 17,524 $ 8,552
Restructured Loans Past Due in Excess of 90 Days on Financing Receivables	Additional information related to restructured loans was as follows: 2022 2021 2020 Restructured loans past due in excess of 90 days at period-end: Number of loans — 2 1 Dollar amount of loans $ — $ 1,027 $ 2,008 Restructured loans on non-accrual status at period end 1,051 3,439 8,552 Charge-offs of restructured loans: Recognized in connection with restructuring — — 337 Recognized on previously restructured loans 723 4,278 3,894 Proceeds from sale of restructured loans 1,070 — —
Weighted Average Risk Grades for All Commercial Loans by Class and Year of Origination	The following tables present weighted-average risk grades for all commercial loans, by class and year of origination/renewal as of December 31, 2022 and 2021. Paycheck Protection Program (“PPP”) loans are excluded as such loans are fully guaranteed by the Small Business Administration (“SBA”). December 31, 2022 2022 2021 2020 2019 2018 Prior Revolving Loans Revolving Loans Converted to Term Total Commercial and industrial Risk grades 1-8 $ 1,667,274 $ 618,756 $ 485,908 $ 226,835 $ 123,768 $ 192,791 $ 2,068,891 $ 51,694 $ 5,435,917 Risk grade 9 31,275 34,950 3,651 5,400 11,006 1,014 54,856 4,040 146,192 Risk grade 10 2,294 724 845 4,713 1,341 114 23,880 3,685 37,596 Risk grade 11 2,342 1,357 6,720 1,807 1,229 1,644 19,582 2,282 36,963 Risk grade 12 — 1,052 866 2,972 1,177 191 673 5,590 12,521 Risk grade 13 — 200 223 270 20 — 2,300 2,596 5,609 $ 1,703,185 $ 657,039 $ 498,213 $ 241,997 $ 138,541 $ 195,754 $ 2,170,182 $ 69,887 $ 5,674,798 W/A risk grade 6.37 7.05 6.01 6.59 6.87 5.55 6.26 7.68 6.39 Energy Risk grades 1-8 $ 338,050 $ 99,089 $ 4,917 $ 3,138 $ 2,020 $ 2,850 $ 393,957 $ 43,161 $ 887,182 Risk grade 9 1,561 1,611 166 562 748 — 6,434 30 11,112 Risk grade 10 — — — 428 214 — — — 642 Risk grade 11 7,956 162 157 3,145 86 63 — — 11,569 Risk grade 12 3,995 — 72 1,386 10 — 4,571 806 10,840 Risk grade 13 662 — — — — — 3,060 662 4,384 $ 352,224 $ 100,862 $ 5,312 $ 8,659 $ 3,078 $ 2,913 $ 408,022 $ 44,659 $ 925,729 W/A risk grade 6.09 5.65 7.65 9.64 8.02 6.59 5.18 5.69 5.67 Commercial real estate: Buildings, land, other Risk grades 1-8 $ 1,811,069 $ 1,484,811 $ 956,567 $ 708,942 $ 360,154 $ 800,944 $ 111,778 $ 105,763 $ 6,340,028 Risk grade 9 52,288 13,139 36,264 22,086 17,699 45,590 652 2,210 189,928 Risk grade 10 26,688 11,150 3,735 9,008 29,683 5,221 5,535 — 91,020 Risk grade 11 10,199 19,073 12,631 4,778 2,525 28,841 2,993 510 81,550 Risk grade 12 1,049 — — 217 266 1,425 — — 2,957 Risk grade 13 595 — — — — — — — 595 $ 1,901,888 $ 1,528,173 $ 1,009,197 $ 745,031 $ 410,327 $ 882,021 $ 120,958 $ 108,483 $ 6,706,078 W/A risk grade 7.01 7.26 7.14 7.01 7.33 6.94 7.38 6.43 7.09 Construction Risk grades 1-8 $ 640,948 $ 489,391 $ 128,788 $ 2,236 $ 486 $ 1,726 $ 163,293 $ 3,144 $ 1,430,012 Risk grade 9 12,865 2,100 2,100 — — — 17,887 — 34,952 Risk grade 10 859 72 — — — — — — 931 Risk grade 11 11,352 — — — — — — — 11,352 Risk grade 12 — — — — — — — — — Risk grade 13 — — — — — — — — — $ 666,024 $ 491,563 $ 130,888 $ 2,236 $ 486 $ 1,726 $ 181,180 $ 3,144 $ 1,477,247 W/A risk grade 7.29 7.03 6.43 7.04 6.00 6.76 7.23 5.03 7.12 Total commercial real estate $ 2,567,912 $ 2,019,736 $ 1,140,085 $ 747,267 $ 410,813 $ 883,747 $ 302,138 $ 111,627 $ 8,183,325 W/A risk grade 7.08 7.20 7.06 7.01 7.33 6.94 7.29 6.39 7.10 December 31, 2021 2021 2020 2019 2018 2017 Prior Revolving Loans Revolving Loans Converted to Term Total Commercial and industrial Risk grades 1-8 $ 1,567,883 $ 657,529 $ 350,563 $ 179,209 $ 146,064 $ 131,201 $ 1,987,061 $ 44,337 $ 5,063,847 Risk grade 9 32,866 21,094 24,683 26,327 612 11,419 65,131 5,738 187,870 Risk grade 10 27,961 6,273 4,047 4,357 1,021 98 14,091 1,289 59,137 Risk grade 11 1,178 4,572 8,068 2,450 2,460 221 4,714 7,855 31,518 Risk grade 12 456 2,495 3,828 1,756 347 353 613 2,687 12,535 Risk grade 13 180 1,361 1,219 64 418 — 4,022 2,783 10,047 $ 1,630,524 $ 693,324 $ 392,408 $ 214,163 $ 150,922 $ 143,292 $ 2,075,632 $ 64,689 $ 5,364,954 W/A risk grade 5.91 6.30 6.89 7.06 5.91 5.80 6.21 8.04 6.22 Energy Risk grades 1-8 $ 445,489 $ 8,075 $ 9,259 $ 6,441 $ 3,110 $ 4,368 $ 464,454 $ 67,174 $ 1,008,370 Risk grade 9 19,274 611 1,775 187 — 724 11,635 2,416 36,622 Risk grade 10 — 101 631 511 — — — 530 1,773 Risk grade 11 10,260 752 3,968 1,016 — 546 — 52 16,594 Risk grade 12 — — 3,888 246 — — 4,000 819 8,953 Risk grade 13 — — 1,470 1,079 — — 2,931 — 5,480 $ 475,023 $ 9,539 $ 20,991 $ 9,480 $ 3,110 $ 5,638 $ 483,020 $ 70,991 $ 1,077,792 W/A risk grade 6.21 7.81 9.34 8.60 7.12 7.63 5.61 6.46 6.06 Commercial real estate: Buildings, land, other Risk grades 1-8 $ 1,707,550 $ 1,096,274 $ 874,130 $ 533,362 $ 492,492 $ 713,268 $ 52,150 $ 105,696 $ 5,574,922 Risk grade 9 16,302 145,340 52,427 43,806 27,188 27,767 4,445 4,258 321,533 Risk grade 10 28,209 13,813 69,643 46,250 64,950 46,582 — — 269,447 Risk grade 11 3,455 1,321 8,720 7,788 26,107 34,970 3,000 5,779 91,140 Risk grade 12 5,838 307 3,446 814 2,030 2,662 — — 15,097 Risk grade 13 200 — — — — — — — 200 $ 1,761,554 $ 1,257,055 $ 1,008,366 $ 632,020 $ 612,767 $ 825,249 $ 59,595 $ 115,733 $ 6,272,339 W/A risk grade 7.19 7.18 7.35 7.39 7.34 7.01 7.06 7.02 7.22 Construction Risk grades 1-8 $ 657,471 $ 262,176 $ 178,226 $ 2,339 $ 38 $ 1,930 $ 160,020 $ — $ 1,262,200 Risk grade 9 35,721 4,956 — — 446 — — — 41,123 Risk grade 10 — — — — — — — — — Risk grade 11 — — — — — — — — — Risk grade 12 — 748 — — — — — — 748 Risk grade 13 — 200 — — — — — — 200 $ 693,192 $ 268,080 $ 178,226 $ 2,339 $ 484 $ 1,930 $ 160,020 $ — $ 1,304,271 W/A risk grade 7.17 6.56 7.60 7.51 8.92 6.73 6.79 — 7.06 Total commercial real estate $ 2,454,746 $ 1,525,135 $ 1,186,592 $ 634,359 $ 613,251 $ 827,179 $ 219,615 $ 115,733 $ 7,576,610 W/A risk grade 7.18 7.07 7.39 7.39 7.34 7.00 6.86 7.02 7.19
Age analysis of Past Due Consumer Loans by Class and Year of Origination	Information about the payment status of consumer loans, segregated by portfolio segment and year of origination, as of December 31, 2022 and December 31, 2021 was as follows: December 31, 2022 2022 2021 2020 2019 2018 Prior Revolving Loans Revolving Loans Converted to Term Total Consumer real estate: Past due 30-89 days $ 793 $ 1,125 $ 645 $ 936 $ 503 $ 2,087 $ 565 $ 1,202 $ 7,856 Past due 90 or more days 95 258 28 — 129 919 347 914 2,690 Total past due 888 1,383 673 936 632 3,006 912 2,116 10,546 Current loans 403,587 313,222 194,900 70,723 38,904 122,585 678,418 10,654 1,832,993 Total $ 404,475 $ 314,605 $ 195,573 $ 71,659 $ 39,536 $ 125,591 $ 679,330 $ 12,770 $ 1,843,539 Consumer and other: Past due 30-89 days $ 2,673 $ 511 $ 128 $ 51 $ 4 $ 31 $ 314 $ 1,443 $ 5,155 Past due 90 or more days 77 2 — 13 — — 25 194 311 Total past due 2,750 513 128 64 4 31 339 1,637 5,466 Current loans 59,886 20,887 6,475 2,897 1,271 1,632 372,117 22,095 487,260 Total $ 62,636 $ 21,400 $ 6,603 $ 2,961 $ 1,275 $ 1,663 $ 372,456 $ 23,732 $ 492,726 December 31, 2021 2021 2020 2019 2018 2017 Prior Revolving Loans Revolving Loans Converted to Term Total Consumer real estate: Past due 30-89 days $ 280 $ 204 $ 406 $ 489 $ 296 $ 1,344 $ 126 $ 1,732 $ 4,877 Past due 90 or more days — — — 154 355 828 991 185 2,513 Total past due 280 204 406 643 651 2,172 1,117 1,917 7,390 Current loans 319,042 251,160 95,900 55,893 48,841 116,423 505,333 10,808 1,403,400 Total $ 319,322 $ 251,364 $ 96,306 $ 56,536 $ 49,492 $ 118,595 $ 506,450 $ 12,725 $ 1,410,790 Consumer and other: Past due 30-89 days $ 1,600 $ 91 $ 120 $ 38 $ 51 $ 17 $ 325 $ 1,943 $ 4,185 Past due 90 or more days 548 — 45 — — — 34 449 1,076 Total past due 2,148 91 165 38 51 17 359 2,392 5,261 Current loans 46,708 17,843 6,215 2,684 1,708 1,158 371,866 23,926 472,108 Total $ 48,856 $ 17,934 $ 6,380 $ 2,722 $ 1,759 $ 1,175 $ 372,225 $ 26,318 $ 477,369
Financing Receivable Revolving Loans Converted to Term	Revolving loans that converted to term during 2022 and 2021 were as follows: 2022 2021 Commercial and industrial $ 34,247 $ 40,099 Energy 3,295 54,996 Commercial real estate: Buildings, land and other 12,174 68,337 Construction 3,144 — Consumer real estate 5,381 1,156 Consumer and other 9,200 8,367 Total $ 67,441 $ 172,955
Financing Receivable, Allowance for Credit Loss By Loan Class Calculated in Accordance With CECL Methodology	The following table presents details of the allowance for credit losses on loans segregated by loan portfolio segment as of December 31, 2022 and 2021, calculated in accordance with the CECL methodology described above. No allowance for credit losses has been recognized for PPP loans as such loans are fully guaranteed by the SBA. Commercial Energy Commercial Consumer Consumer Total December 31, 2022 Modeled expected credit losses $ 61,918 $ 8,531 $ 27,013 $ 7,847 $ 4,983 $ 110,292 Q-Factor and other qualitative adjustments 36,237 5,148 61,572 157 2,034 105,148 Specific allocations 6,082 4,383 1,716 — — 12,181 Total $ 104,237 $ 18,062 $ 90,301 $ 8,004 $ 7,017 $ 227,621 December 31, 2021 Modeled expected credit losses $ 46,946 $ 6,363 $ 16,676 $ 6,484 $ 6,397 $ 82,866 Q-Factor and other qualitative adjustments 14,609 5,374 127,860 65 1,440 149,348 Specific allocations 10,536 5,480 400 36 — 16,452 Total $ 72,091 $ 17,217 $ 144,936 $ 6,585 $ 7,837 $ 248,666
Activity in Allowance for Loan Losses by Portfolio Segment	The following table details activity in the allowance for credit losses on loans by portfolio segment for 2022, 2021 and 2020. Allocation of a portion of the allowance to one category of loans does not preclude its availability to absorb losses in other categories. No allowance for credit losses has been recognized for PPP loans as such loans are fully guaranteed by the SBA. Commercial Energy Commercial Consumer Consumer Total 2022 Beginning balance $ 72,091 $ 17,217 $ 144,936 $ 6,585 $ 7,837 $ 248,666 Credit loss expense (benefit) 34,479 (313) (54,775) 1,813 13,517 (5,279) Charge-offs (6,575) (371) (702) (912) (24,388) (32,948) Recoveries 4,242 1,529 842 518 10,051 17,182 Net (charge-offs) recoveries (2,333) 1,158 140 (394) (14,337) (15,766) Ending balance $ 104,237 $ 18,062 $ 90,301 $ 8,004 $ 7,017 $ 227,621 2021 Beginning balance $ 73,843 $ 39,553 $ 134,892 $ 7,926 $ 6,963 $ 263,177 Credit loss expense (benefit) (2,160) (19,207) 8,101 (3,061) 10,230 (6,097) Charge-offs (5,513) (5,331) (399) (829) (18,614) (30,686) Recoveries 5,921 2,202 2,342 2,549 9,258 22,272 Net (charge-offs) recoveries 408 (3,129) 1,943 1,720 (9,356) (8,414) Ending balance $ 72,091 $ 17,217 $ 144,936 $ 6,585 $ 7,837 $ 248,666 2020 Beginning balance $ 51,593 $ 37,382 $ 31,037 $ 4,113 $ 8,042 $ 132,167 Impacting of adopting ASC 326 21,263 (10,453) (13,519) 2,392 (2,248) (2,565) Credit loss expense (benefit) 15,156 85,889 124,427 1,906 9,632 237,010 Charge-offs (18,908) (76,107) (7,499) (2,186) (17,830) (122,530) Recoveries 4,739 2,842 446 1,701 9,367 19,095 Net (charge-offs) recoveries (14,169) (73,265) (7,053) (485) (8,463) (103,435) Ending balance $ 73,843 $ 39,553 $ 134,892 $ 7,926 $ 6,963 $ 263,177
Investment in Loans Related to the Allowance for Loan Losses by Portfolio Segment Disaggregated Based on Impairment Methodology	The following table presents loans that were evaluated for expected credit losses on an individual basis and the related specific allocations, by loan portfolio segment as of December 31, 2022 and December 31, 2021. December 31, 2022 December 31, 2021 Loan Specific Allocations Loan Specific Allocations Commercial and industrial $ 18,980 $ 6,082 $ 24,523 $ 10,536 Energy 15,058 4,383 16,393 5,480 Paycheck Protection Program — — — — Commercial real estate: Buildings, land and other 17,711 1,716 24,670 200 Construction — — 948 200 Consumer real estate 827 — 303 36 Consumer and other — — — — Total $ 52,576 $ 12,181 $ 66,837 $ 16,452

Premises and Equipment (Tables)

Premises and Equipment (Tables)	12 Months Ended
Premises and Equipment (Tables)	Dec. 31, 2022
Property, Plant and Equipment [Abstract]
Premises and Equipment	Year-end premises and equipment were as follows: 2022 2021 Land $ 170,938 $ 152,219 Buildings 521,280 495,903 Technology, furniture and equipment 236,440 256,323 Leasehold improvements 209,398 192,207 Construction and projects in progress 39,506 14,513 Lease right-of-use assets 288,816 281,438 1,466,378 1,392,603 Less accumulated depreciation and amortization (363,683) (342,272) Total premises and equipment, net $ 1,102,695 $ 1,050,331
Lease Commitments, Components of Lease Expense	The components of total lease expense in 2022 and 2021 were as follows: 2022 2021 Amortization of lease right-of-use assets $ 33,285 $ 32,811 Short-term lease expense 2,208 1,595 Non-lease components (including taxes, insurance, common maintenance, etc.) 12,172 11,203 Total $ 47,665 $ 45,609
Lessee, Operating Lease, Liability, Maturity	The following table reconciles future undiscounted lease payments due under non-cancelable operating leases (those amounts subject to recognition) to the aggregate operating lessee lease liability as of December 31, 2022: Future lease payments 2023 $ 33,685 2024 33,651 2025 33,990 2026 33,600 2027 32,023 Thereafter 232,905 Total undiscounted operating lease liability 399,854 Imputed interest 77,909 Total operating lease liability included in the accompanying balance sheet $ 321,945 Weighted-average lease term in years 13.62 Weighted-average discount rate 3.13%

Goodwill and Other Intangible_2

Goodwill and Other Intangible Assets (Tables)	12 Months Ended
Goodwill and Other Intangible Assets (Tables)	Dec. 31, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill	Goodwill . Year-end goodwill was as follows: 2022 2021 Goodwill $ 654,952 $ 654,952
Schedule of Other Intangible Assets	Other Intangible Assets. Year-end other intangible assets were as follows: Gross Accumulated Net 2022 Core deposits $ 9,300 $ (8,990) $ 310 Customer relationships 1,521 (1,445) 76 $ 10,821 $ (10,435) $ 386 2021 Core deposits $ 9,300 $ (8,582) $ 718 Customer relationships 2,385 (2,237) 148 $ 11,685 $ (10,819) $ 866
Estimated Aggregate Future Amortization Expense for Intangible Assets	The estimated aggregate future amortization expense for intangible assets remaining as of December 31, 2022 is as follows: 2023 $ 283 2024 87 2025 11 2026 5 $ 386

Deposits (Tables)

Deposits (Tables)	12 Months Ended
Deposits (Tables)	Dec. 31, 2022
Deposits [Abstract]
Deposit Liabilities, Type	Year-end deposits were as follows: 2022 2021 Non-interest-bearing demand deposits $ 17,598,234 $ 18,423,018 Interest-bearing deposits: Savings and interest checking 12,333,675 11,930,959 Money market accounts 12,227,247 11,228,815 Time accounts 1,795,040 1,112,904 Total interest-bearing deposits 26,355,962 24,272,678 Total deposits $ 43,954,196 $ 42,695,696
Additional Information About Corporation's Deposits	The following table presents additional information about our year-end deposits: 2022 2021 Deposits from foreign sources (primarily Mexico) $ 1,048,943 $ 993,479 Non-interest-bearing public funds deposits 788,040 1,235,026 Interest-bearing public funds deposits 758,761 810,863 Total deposits not covered by deposit insurance 23,839,797 24,125,359 Time deposits not covered by deposit insurance 430,128 238,608 Deposits from certain directors, executive officers and their affiliates 153,083 276,556
Scheduled Maturities of Time Deposits	Scheduled maturities of time deposits at December 31, 2022 were as follows: 2023 $ 1,381,519 2024 413,521 $ 1,795,040
Time Deposit Maturities	Scheduled maturities of time deposits not covered by deposit insurance at December 31, 2022, were as follows: Due within 3 months or less $ 87,254 Due after 3 months and within 6 months 87,035 Due after 6 months and within 12 months 131,503 Due after 12 months 124,336 $ 430,128

Off-Balance-Sheet Arrangement_2

Off-Balance-Sheet Arrangements, Commitments, Guarantees and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Financial Instruments With Off-Balance-Sheet Risk	Year-end financial instruments with off-balance-sheet risk are presented in the following table. Commitments and standby letters of credit are presented at contractual amounts; however, since many of these commitments are expected to expire unused or only partially used, the total amounts of these commitments do not necessarily reflect future cash requirements. 2022 2021 Commitments to extend credit $ 12,137,957 $ 10,420,142 Standby letters of credit 383,851 238,690 Deferred standby letter of credit fees 2,236 2,072
Commitments, Off-Balance-Sheet, Allowance for Credit Losses	The following table details activity in the allowance for credit losses on off-balance-sheet credit exposures. 2022 2021 2020 Beginning balance $ 50,314 $ 44,152 $ 500 Impact of adopting ASC 326 — — 39,377 Credit loss expense 8,279 6,162 4,275 Ending balance $ 58,593 $ 50,314 $ 44,152

Capital and Regulatory Matters

Capital and Regulatory Matters (Tables)	12 Months Ended
Capital and Regulatory Matters (Tables)	Dec. 31, 2022
Broker-Dealer, Net Capital Requirement, SEC Regulation [Abstract]
Actual and Required Capital Ratios	The following table presents actual and required capital ratios as of December 31, 2022 and December 31, 2021 for Cullen/Frost and Frost Bank under the Basel III Capital Rules. Capital levels required to be considered well capitalized are based upon prompt corrective action regulations, as amended to reflect the changes under the Basel III Capital Rules. Actual Minimum Capital Required to be Considered Well Capitalized (1) Capital Ratio Capital Ratio Capital Ratio 2022 Common Equity Tier 1 to Risk-Weighted Assets Cullen/Frost $ 3,751,200 12.85 % $ 2,042,876 7.00 % N/A N/A Frost Bank 3,789,056 13.00 2,040,388 7.00 $ 1,894,646 6.50 % Tier 1 Capital to Risk-Weighted Assets Cullen/Frost 3,896,652 13.35 2,480,635 8.50 1,751,036 6.00 Frost Bank 3,789,056 13.00 2,477,614 8.50 2,331,872 8.00 Total Capital to Risk-Weighted Assets Cullen/Frost 4,330,982 14.84 3,064,313 10.50 2,918,394 10.00 Frost Bank 4,023,386 13.80 3,060,583 10.50 2,914,841 10.00 Leverage Ratio Cullen/Frost 3,896,652 7.29 2,136,680 4.00 N/A N/A Frost Bank 3,789,056 7.09 2,136,316 4.00 2,670,395 5.00 2021 Common Equity Tier 1 to Risk-Weighted Assets Cullen/Frost $ 3,371,043 13.13 % $ 1,796,549 7.00 % N/A N/A Frost Bank 3,261,532 12.72 1,795,221 7.00 $ 1,666,991 6.50 % Tier 1 Capital to Risk-Weighted Assets Cullen/Frost 3,516,495 13.70 2,181,523 8.50 1,539,899 6.00 Frost Bank 3,261,532 12.72 2,179,911 8.50 2,051,681 8.00 Total Capital to Risk-Weighted Assets Cullen/Frost 3,966,244 15.45 2,694,823 10.50 2,566,498 10.00 Frost Bank 3,491,281 13.61 2,692,831 10.50 2,564,601 10.00 Leverage Ratio Cullen/Frost 3,516,495 7.34 1,917,533 4.00 N/A N/A Frost Bank 3,261,532 6.80 1,917,679 4.00 2,397,099 5.00 ____________________ (1) “Well-capitalized” minimum Common Equity Tier 1 to Risk-Weighted Assets and Leverage Ratio are not formally defined under applicable banking regulations for bank holding companies.

Earnings Per Common Share (Tabl

Earnings Per Common Share (Tables)	12 Months Ended
Earnings Per Common Share (Tables)	Dec. 31, 2022
Earnings Per Share [Abstract]
Basic and Diluted Earnings Per Common Share	The following table presents a reconciliation of net income available to common shareholders, net earnings allocated to common stock and the number of shares used in the calculation of basic and diluted earnings per common share. 2022 2021 2020 Net Income $ 579,150 $ 443,079 $ 331,151 Less: Preferred stock dividends 6,675 7,157 2,016 Redemption of preferred stock — — 5,514 Net income available to common shareholders 572,475 435,922 323,621 Less: Earnings allocated to participating securities 5,210 3,881 3,136 Net earnings allocated to common stock $ 567,265 $ 432,041 $ 320,485 Distributed earnings allocated to common stock $ 207,924 $ 187,202 $ 178,863 Undistributed earnings allocated to common stock 359,341 244,839 141,622 Net earnings allocated to common stock $ 567,265 $ 432,041 $ 320,485 Weighted-average shares outstanding for basic earnings per common share 64,156,870 63,612,658 62,727,053 Dilutive effect of stock compensation 363,648 489,462 276,784 Weighted-average shares outstanding for diluted earnings per common share 64,520,518 64,102,120 63,003,837

Employee Benefit Plans (Tables)

Employee Benefit Plans (Tables)	12 Months Ended
Employee Benefit Plans (Tables)	Dec. 31, 2022
Retirement Benefits [Abstract]
Combined Activity in Corporations Defined Benefit Pension Plans	We use a December 31 measurement date for our defined benefit plans. Combined activity in our defined benefit pension plans was as follows: 2022 2021 2020 Change in plan assets: Fair value of plan assets at beginning of year $ 197,747 $ 182,088 $ 174,173 Actual return on plan assets (26,108) 24,908 16,599 Employer contributions 1,114 1,236 1,201 Benefits paid (10,930) (10,485) (9,885) Fair value of plan assets at end of year 161,823 197,747 182,088 Change in benefit obligation: Benefit obligation at beginning of year 185,925 197,593 186,641 Interest cost 4,017 3,341 5,010 Actuarial (gain) loss (35,068) (4,524) 15,827 Benefits paid (10,930) (10,485) (9,885) Benefit obligation at end of year 143,944 185,925 197,593 Funded status of the plan at end of year and accrued benefit (liability) recognized $ 17,879 $ 11,822 $ (15,505) Accumulated benefit obligation at end of year $ 143,944 $ 185,925 $ 197,593
Disaggregated Information Related to Corporations Defined Benefit Pension Plans	Certain disaggregated information related to our defined benefit pension plans as of year-end was as follows: Retirement Plan Restoration Plan 2022 2021 2022 2021 Projected benefit obligation $ 131,648 $ 170,389 $ 12,296 $ 15,536 Accumulated benefit obligation 131,648 170,389 12,296 15,536 Fair value of plan assets 161,823 197,747 — — Funded status of the plan at end of year and accrued benefit (liability) recognized 30,175 27,358 (12,296) (15,536)
Net Periodic Benefit Cost (Benefit)	The components of the combined net periodic cost (benefit) for our defined benefit pension plans are presented in the table below. 2022 2021 2020 Expected return on plan assets, net of expenses $ (13,966) $ (12,839) $ (12,289) Interest cost on projected benefit obligation 4,017 3,341 5,010 Net amortization and deferral 2,964 6,116 5,319 Net periodic expense (benefit) $ (6,985) $ (3,382) $ (1,960)
Defined Benefit Pension Plans Recognized as Component of Other Comprehensive Income	Amounts related to our defined benefit pension plans recognized as a component of other comprehensive income were as follows: 2022 2021 2020 Net actuarial gain (loss) $ (2,041) $ 22,709 $ (6,199) Deferred tax (expense) benefit 429 (4,769) 1,302 Other comprehensive income (loss), net of tax $ (1,612) $ 17,940 $ (4,897)
Defined Benefit Pension Plans Not Recognized as Component of Combined Net Period Benefit Cost	Amounts recognized as a component of accumulated other comprehensive loss as of year-end that have not been recognized as a component of the combined net periodic benefit cost of our defined benefit pension plans are presented in the following table. 2022 2021 Net actuarial loss $ (43,675) $ (41,634) Deferred tax benefit 9,172 8,743 Amounts included in accumulated other comprehensive income/loss, net of tax (34,503) (32,891)
Weighted-Average Assumptions Used to Determine Benefit Obligations	The weighted-average assumptions used to determine the benefit obligations as of the end of the years indicated and the net periodic benefit cost for the years indicated are presented in the table below. Because the plans were frozen, increases in compensation are not considered after 2001. 2022 2021 2020 Benefit obligations: Discount rate 5.14 % 2.79 % 2.43 % Net periodic benefit cost: Discount rate 2.79 % 2.43 % 3.20 % Expected return on plan assets 7.25 7.25 7.25
Fair Value of Plan Assets	The major categories of assets in our Retirement Plan as of year-end are presented in the following table. Assets are segregated by the level of the valuation inputs within the fair value hierarchy established by ASC Topic 820 “Fair Value Measurements and Disclosures,” utilized to measure fair value (see Note 17 - Fair Value Measurements). Our Restoration Plan is unfunded. 2022 2021 Level 1: Mutual funds $ 154,391 $ 195,452 Cash and cash equivalents 7,432 2,295 Total fair value of plan assets $ 161,823 $ 197,747
Expected Future Benefit Payments Related to Defined Benefit Plans	As of December 31, 2022, expected future benefit payments related to our defined benefit plans were as follows: 2023 $ 11,864 2024 12,128 2025 12,059 2026 11,995 2027 11,848 2028 through 2032 55,245 $ 115,139
Disclosure of Share-based Compensation Arrangements by Share-based Payment Award [Table Text Block]	A combined summary of activity in our active stock plans is presented in the table. Performance stock units outstanding are presented assuming attainment of the maximum payout rate as set forth by the performance criteria. The target award level for performance stock units granted in 2022, 2021 and 2020 was 35,015, 30,723 and 48,409, respectively. As of December 31, 2022, there were 505,456 shares remaining available for grant for future awards. Director Deferred Non-Vested Stock Performance Stock Units Outstanding Stock Options Number of Units Weighted- Number Weighted- Number of Units Weighted- Number Weighted- January 1, 2020 55,370 $ 74.76 440,647 $ 90.22 177,288 $ 83.48 1,980,866 $ 64.60 Granted 10,428 73.84 151,038 66.79 72,618 57.89 — — Exercised/vested (12,938) 71.09 (117,990) 76.07 (41,755) 69.70 (235,880) 53.23 Forfeited/expired — — (3,336) 91.07 (6,894) 81.33 (5,427) 75.74 December 31, 2020 52,860 75.47 470,359 86.24 201,257 77.18 1,739,559 66.11 Granted 5,940 117.90 95,258 130.36 46,086 121.46 — — Exercised/vested (2,499) 92.03 (88,250) 98.90 (35,131) 92.27 (861,878) 63.14 Forfeited/expired — — (28,030) 87.08 (9,752) 75.70 — — December 31, 2021 56,301 79.21 449,337 93.05 202,460 84.71 877,681 69.02 Granted 5,382 133.67 119,176 142.56 52,527 133.40 — — Exercised/vested (16,022) 74.89 (97,154) 94.81 (25,180) 87.18 (261,454) 63.72 Forfeited/expired — — (6,040) 93.28 (16,058) 87.18 — — December 31, 2022 45,661 87.15 465,319 105.36 213,749 96.20 616,227 71.27
Options Outstanding and Exercisable	Other information regarding options outstanding and exercisable as of December 31, 2022 is as follows: Options Outstanding Options Exercisable Range of Number Weighted- Weighted- Number Weighted- $ 65.01 to $ 70.00 277,131 $ 65.11 2.82 277,131 $ 65.11 70.01 to 75.00 117,686 71.39 0.83 117,686 71.39 75.01 to 80.00 221,410 78.92 1.83 221,410 78.92 Total 616,227 71.27 2.08 616,227 71.27 Total intrinsic value $ 38,470 $ 38,470
Shares Issued in Connection With Stock Compensation Awards	Shares issued in connection with stock compensation awards are issued from available treasury shares. If no treasury shares are available, new shares are issued from available authorized shares. Shares issued in connection with stock compensation awards along with other related information were as follows: 2022 2021 2020 New shares issued from available authorized shares 118,389 — — Shares issued from available treasury stock 281,421 987,758 408,563 Total 399,810 987,758 408,563 Proceeds from stock option exercises $ 16,659 $ 54,417 $ 12,557 Intrinsic value of stock options exercised 19,616 43,904 5,365 Fair value of stock awards/units vested 19,308 15,751 12,773
Stock-Based Compensation Expense	Stock-based compensation expense and the related income tax benefit is presented in the following table. The service period for performance stock units granted each year begins on January 1 of the following year. 2022 2021 2020 Non-vested stock awards/stock units $ 13,162 $ 9,977 $ 10,240 Deferred stock-units 720 700 770 Performance stock units 4,440 2,076 2,908 Total $ 18,322 $ 12,753 $ 13,918 Income tax benefit $ 2,969 $ 1,713 $ 2,142
Unrecognized Stock-Based Compensation Expense	Unrecognized stock-based compensation expense and the weighted-average period over which the expense is expected to be recognized at December 31, 2022 is presented in the table below. Unrecognized stock-based compensation expense related to performance stock units is presented assuming attainment of the maximum payout rate as set forth by the performance criteria. Unrecognized Expense Weighted-Average Number of Years for Expense Recognition Non-vested stock awards/stock units $ 21,770 2.15 Performance stock units 11,078 1.80 Total $ 32,848

Other Non-Interest Income and_2

Other Non-Interest Income and Expense (Tables)	12 Months Ended
Other Non-Interest Income and Expense (Tables)	Dec. 31, 2022
Other Income and Expenses [Abstract]
Other Non-Interest Income and Expense	Other non-interest income and expense totals are presented in the following table. Components of these totals exceeding 1% of the aggregate of total net interest income and total non-interest income for any of the years presented are stated separately. 2022 2021 2020 Other non-interest income: Other $ 45,217 $ 48,528 $ 47,712 Total $ 45,217 $ 48,528 $ 47,712 Other non-interest expense: Professional services $ 40,908 $ 34,747 $ 37,253 Advertising, promotions and public relations 39,994 34,539 34,390 Other 113,319 102,171 94,667 Total $ 194,221 $ 171,457 $ 166,310

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
Income Taxes (Tables)	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Income Tax Expense	Income tax expense was as follows: 2022 2021 2020 Current income tax expense $ 94,595 $ 38,675 $ 36,002 Deferred income tax expense (benefit) (4,918) 7,784 (15,832) Income tax expense, as reported $ 89,677 $ 46,459 $ 20,170 Effective tax rate 13.4 % 9.5 % 5.7 %
Income Tax Computed by Applying U.S. Federal Statutory Income Tax Rate	A reconciliation between reported income tax expense and the amounts computed by applying the U.S. federal statutory income tax rate of 21% to income before income taxes is presented in the following table. 2022 2021 2020 Income tax expense computed at the statutory rate $ 140,454 $ 102,803 $ 73,777 Effect of tax-exempt interest (50,602) (50,740) (51,624) Net tax benefit from stock-based compensation (4,602) (7,877) (852) Tax benefit on dividends paid in our 401k plan (1,854) (1,764) (1,851) Bank owned life insurance income (440) (517) (783) Non-deductible FDIC premiums 3,277 2,629 1,790 Non-deductible compensation 2,250 1,773 1,123 Non-deductible meals and entertainment 683 625 786 Asset contribution to a charitable trust — — (2,556) Tax basis adjustment of premises and equipment — (1,026) — Other 511 553 360 Income tax expense, as reported $ 89,677 $ 46,459 $ 20,170
Schedule of Deferred Tax Assets and Liabilities	Year-end deferred taxes are presented in the table below. Deferred taxes are based on the U.S. statutory federal income tax rate of 21%. 2022 2021 Deferred tax assets: Lease liabilities under operating leases $ 67,608 $ 65,815 Net unrealized loss on securities available for sale and transferred securities 349,237 — Allowance for credit losses 60,137 62,819 Net actuarial loss on defined benefit post-retirement benefit plans 9,172 8,743 Stock-based compensation 6,622 6,989 Bonus accrual 11,204 7,506 Deferred loan and lease origination fees 3,675 3,118 Other 6,109 3,834 Total gross deferred tax assets 513,764 158,824 Deferred tax liabilities: Net unrealized gain on securities available for sale and transferred securities — (101,067) Right-of-use assets under operating leases (60,651) (59,415) Premises and equipment (45,647) (49,645) Intangible assets (17,732) (16,595) Defined benefit post-retirement benefit plans (12,730) (11,027) Other (2,601) (2,323) Total gross deferred tax liabilities (139,361) (240,072) Net deferred tax asset (liability) $ 374,403 $ (81,248)

Other Comprehensive Income (L_2

Other Comprehensive Income (Loss) (Tables)	12 Months Ended
Other Comprehensive Income (Loss) (Tables)	Dec. 31, 2022
Equity [Abstract]
Component of Other Comprehensive Income (Loss)	The tax effects allocated to each component of other comprehensive income (loss) were as follows: Before Tax Tax Expense, Net of Tax 2022 Securities available for sale and transferred securities: Change in net unrealized gain/loss during the period $ (2,143,567) $ (450,149) $ (1,693,418) Change in net unrealized gain on securities transferred to held to maturity (737) (155) (582) Reclassification adjustment for net (gains) losses included in net income — — — Total securities available for sale and transferred securities (2,144,304) (450,304) (1,694,000) Defined-benefit post-retirement benefit plans: Change in the net actuarial gain/loss (5,005) (1,051) (3,954) Reclassification adjustment for net amortization of actuarial gain/loss included in net income as a component of net periodic cost (benefit) 2,964 622 2,342 Total defined-benefit post-retirement benefit plans (2,041) (429) (1,612) Total other comprehensive income (loss) $ (2,146,345) $ (450,733) $ (1,695,612) 2021 Securities available for sale and transferred securities: Change in net unrealized gain/loss during the period $ (231,355) $ (48,585) $ (182,770) Change in net unrealized gain on securities transferred to held to maturity (971) (204) (767) Reclassification adjustment for net (gains) losses included in net income (69) (14) (55) Total securities available for sale and transferred securities (232,395) (48,803) (183,592) Defined-benefit post-retirement benefit plans: Change in the net actuarial gain/loss 16,593 3,485 13,108 Reclassification adjustment for net amortization of actuarial gain/loss included in net income as a component of net periodic cost (benefit) 6,116 1,284 4,832 Total defined-benefit post-retirement benefit plans 22,709 4,769 17,940 Total other comprehensive income (loss) $ (209,686) $ (44,034) $ (165,652) 2020 Securities available for sale and transferred securities: Change in net unrealized gain/loss during the period $ 427,331 $ 89,741 $ 337,590 Change in net unrealized gain on securities transferred to held to maturity (1,256) (264) (992) Reclassification adjustment for net (gains) losses included in net income (108,989) (22,888) (86,101) Total securities available for sale and transferred securities 317,086 66,589 250,497 Defined-benefit post-retirement benefit plans: Change in the net actuarial gain/loss (11,518) (2,419) (9,099) Reclassification adjustment for net amortization of actuarial gain/loss included in net income as a component of net periodic cost (benefit) 5,319 1,117 4,202 Total defined-benefit post-retirement benefit plans (6,199) (1,302) (4,897) Total other comprehensive income (loss) $ 310,887 $ 65,287 $ 245,600
Schedule of Accumulated Other Comprehensive Income, Net of Tax	Activity in accumulated other comprehensive income, net of tax, was as follows: Securities Defined Accumulated Balance January 1, 2022 $ 380,209 $ (32,891) $ 347,318 Other comprehensive income (loss) before reclassification (1,694,000) (3,954) (1,697,954) Reclassification of amounts included in net income — 2,342 2,342 Net other comprehensive income (loss) during period (1,694,000) (1,612) (1,695,612) Balance December 31, 2022 $ (1,313,791) $ (34,503) $ (1,348,294) Balance January 1, 2021 $ 563,801 $ (50,831) $ 512,970 Other comprehensive income (loss) before reclassification (183,537) 13,108 (170,429) Reclassification of amounts included in net income (55) 4,832 4,777 Net other comprehensive income (loss) during period (183,592) 17,940 (165,652) Balance December 31, 2021 $ 380,209 $ (32,891) $ 347,318 Balance January 1, 2020 $ 313,304 $ (45,934) $ 267,370 Other comprehensive income (loss) before reclassification 336,598 (9,099) 327,499 Reclassification of amounts included in net income (86,101) 4,202 (81,899) Net other comprehensive income (loss) during period 250,497 (4,897) 245,600 Balance December 31, 2020 $ 563,801 $ (50,831) $ 512,970

Derivative Financial Instrume_2

Derivative Financial Instruments (Tables)	12 Months Ended
Derivative Financial Instruments (Tables)	Dec. 31, 2022
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Notional Amounts and Estimated Fair Values of Interest Rate Derivative Contracts Outstanding	The notional amounts and estimated fair values of interest rate derivative contracts outstanding at December 31, 2022 and 2021 are presented in the following table. The fair values of interest rate derivative contracts are estimated utilizing internal valuation methods with observable market data inputs, or as determined by the Chicago Mercantile Exchange (“CME”) for centrally cleared derivative contracts. CME rules legally characterize variation margin payments for centrally cleared derivatives as settlements of the derivatives' exposure rather than collateral. As a result, the variation margin payment and the related derivative instruments are considered a single unit of account for accounting and financial reporting purposes. Variation margin, as determined by the CME, is settled daily. As a result, derivative contracts that clear through the CME have an estimated fair value of zero as of December 31, 2022 and 2021. December 31, 2022 December 31, 2021 Notional Estimated Notional Estimated Derivatives designated as hedges of fair value: Financial institution counterparties: Loan/lease interest rate swaps - assets $ 1,614 $ 19 $ — $ — Loan/lease interest rate swaps - liabilities — — 2,426 (34) Non-hedging interest rate derivatives: Financial institution counterparties: Loan/lease interest rate swaps - assets 1,165,812 70,416 247,592 1,207 Loan/lease interest rate swaps - liabilities 78,798 (1,102) 928,756 (19,142) Loan/lease interest rate caps - assets 246,442 15,256 270,431 3,239 Customer counterparties: Loan/lease interest rate swaps - assets 53,570 1,102 928,756 39,864 Loan/lease interest rate swaps - liabilities 1,175,563 (79,175) 247,592 (2,846) Loan/lease interest rate caps - liabilities 246,442 (15,256) 270,431 (3,239)
Schedule of Weighted-Average Rates Paid and Received for Interest Rate Swaps Outstanding	The weighted-average rates paid and received for interest rate swaps outstanding at December 31, 2022 were as follows: Weighted-Average Interest Interest Interest rate swaps: Fair value hedge loan/lease interest rate swaps 1.58 % 4.12 % Non-hedging interest rate swaps - financial institution counterparties 3.73 5.29 Non-hedging interest rate swaps - customer counterparties 5.28 3.72
Schedule of Notional Amounts and Estimated Fair Values of Commodity Derivative Positions	The notional amounts and estimated fair values of non-hedging commodity swap and option derivative positions outstanding are presented in the following table. We obtain dealer quotations and use internal valuation methods with observable market data inputs to value our commodity derivative positions. December 31, 2022 December 31, 2021 Notional Notional Estimated Notional Estimated Financial institution counterparties: Oil - assets Barrels 4,024 $ 27,082 4,809 $ 14,721 Oil - liabilities Barrels 6,068 (53,579) 7,032 (73,594) Natural gas - assets MMBTUs 16,539 6,220 15,947 4,143 Natural gas - liabilities MMBTUs 15,682 (19,138) 29,446 (21,249) Customer counterparties: Oil - assets Barrels 6,068 54,219 7,046 74,437 Oil - liabilities Barrels 4,024 (26,551) 4,796 (14,294) Natural gas - assets MMBTUs 15,682 19,164 29,446 21,456 Natural gas - liabilities MMBTUs 16,539 (6,124) 15,947 (4,124)
Schedule of Foreign Exchange Contracts, Statement of Financial Position	The notional amounts and fair values of open foreign currency forward contracts were as follows: December 31, 2022 December 31, 2021 Notional Notional Estimated Notional Estimated Financial institution counterparties: Forward/option contracts - assets EUR 875 $ 1 1,900 $ 29 Forward/option contracts - assets CAD — — 658 — Forward/option contracts - liabilities EUR 875 (10) — — Customer counterparties: Forward/option contracts - assets EUR 875 10 — — Forward/option contracts - assets CAD — — 658 4 Forward/option contracts - liabilities EUR 875 (1) 1,900 (55)
Schedule of Amounts Included in Income Related to Interest Rate Derivatives Designated as Hedges of Fair Value	Amounts included in the consolidated statements of income related to interest rate derivatives designated as hedges of fair value were as follows: 2022 2021 2020 Commercial loan/lease interest rate swaps: Amount of gain (loss) included in interest income on loans $ (7) $ (91) $ (111) Amount of (gain) loss included in other non-interest expense 6 10 9
Schedule of Amounts Related to Non-Hedging Interest Rate and Commodity Derivatives	Amounts included in the consolidated statements of income related to non-hedging interest rate, commodity, foreign currency and other derivative instruments are presented in the table below. 2022 2021 2020 Non-hedging interest rate derivatives: Other non-interest income $ 1,742 $ 4,285 $ 3,413 Other non-interest expense — (1) 1 Non-hedging commodity derivatives: Other non-interest income 2,297 4,052 1,768 Non-hedging foreign currency derivatives: Other non-interest income 63 39 28 Non-hedging other derivatives: Other non-interest income — — 5,992

Balance Sheet Offsetting Balanc

Balance Sheet Offsetting Balance Sheet Offsetting (Tables)	12 Months Ended
Balance Sheet Offsetting Balance Sheet Offsetting (Tables)	Dec. 31, 2022	Dec. 31, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Financial Instruments Eligible for Offset Consolidated Balance Sheet	Information about financial instruments that are eligible for offset in the consolidated balance sheet as of December 31, 2022 is presented in the following tables. Gross Amount Gross Amount Net Amount December 31, 2022 Financial assets: Derivatives: Loan/lease interest rate swaps and caps $ 85,691 $ — $ 85,691 Commodity swaps and options 33,302 — 33,302 Foreign currency forward/option contracts 1 — 1 Total derivatives 118,994 — 118,994 Resell agreements 87,150 — 87,150 Total $ 206,144 $ — $ 206,144 Financial liabilities: Derivatives: Loan/lease interest rate swaps $ 1,102 $ — $ 1,102 Commodity swaps and options 72,717 — 72,717 Foreign currency forward/option contracts 10 — 10 Total derivatives 73,829 — 73,829 Repurchase agreements 4,660,641 — 4,660,641 Total $ 4,734,470 $ — $ 4,734,470	Information about financial instruments that are eligible for offset in the consolidated balance sheet as of December 31, 2021 is presented in the following tables. Gross Amount Gross Amount Net Amount December 31, 2021 Financial assets: Derivatives: Loan/lease interest rate swaps and caps $ 4,446 $ — $ 4,446 Commodity swaps and options 18,864 — 18,864 Foreign currency forward/option contracts 29 — 29 Total derivatives 23,339 — 23,339 Resell agreements 7,903 — 7,903 Total $ 31,242 $ — $ 31,242 Financial liabilities: Derivatives: Loan/lease interest rate swaps $ 19,176 $ — $ 19,176 Commodity swaps and options 94,843 — 94,843 Total derivatives 114,019 — 114,019 Repurchase agreements 2,740,799 — 2,740,799 Total $ 2,854,818 $ — $ 2,854,818
Financial Instruments Derivative Assets Liabilities And Resell Agreements Net Of Amount Not Offset	Gross Amounts Not Offset Net Amount Financial Collateral Net December 31, 2022 Financial assets: Derivatives: Counterparty B $ 39,370 $ (24,500) $ (14,870) $ — Counterparty E 14,430 (47) (14,131) 252 Counterparty F 17,297 (17,297) — — Counterparty G 10,660 — (10,660) — Other counterparties 37,237 (20,684) (16,307) 246 Total derivatives 118,994 (62,528) (55,968) 498 Resell agreements 87,150 — (87,150) — Total $ 206,144 $ (62,528) $ (143,118) $ 498 Financial liabilities: Derivatives: Counterparty B $ 24,500 $ (24,500) $ — $ — Counterparty E 47 (47) — — Counterparty F 27,747 (17,297) (8,479) 1,971 Counterparty G — — — — Other counterparties 21,535 (20,684) (851) — Total derivatives 73,829 (62,528) (9,330) 1,971 Repurchase agreements 4,660,641 — (4,660,641) — Total $ 4,734,470 $ (62,528) $ (4,669,971) $ 1,971	Gross Amounts Not Offset Net Amount Financial Collateral Net December 31, 2021 Financial assets: Derivatives: Counterparty B $ 7,655 $ (7,655) $ — $ — Counterparty E 411 (411) — — Counterparty F 12,078 (12,078) — — Counterparty G 1,783 (1,783) — — Other counterparties 1,412 (1,412) — — Total derivatives 23,339 (23,339) — — Resell agreements 7,903 — (7,903) — Total $ 31,242 $ (23,339) $ (7,903) $ — Financial liabilities: Derivatives: Counterparty B $ 28,130 $ (7,655) $ (20,475) $ — Counterparty E 601 (411) (190) — Counterparty F 20,813 (12,078) (8,735) — Counterparty G 1,789 (1,783) (6) — Other counterparties 62,686 (1,412) (61,167) 107 Total derivatives 114,019 (23,339) (90,573) 107 Repurchase agreements 2,740,799 — (2,740,799) — Total $ 2,854,818 $ (23,339) $ (2,831,372) $ 107
Remaining Contractual Maturity of the Securities Sold Under Agreement	The remaining contractual maturity of repurchase agreements in the consolidated balance sheets as of December 31, 2022 and December 31, 2021 is presented in the following tables. Remaining Contractual Maturity of the Agreements Overnight and Continuous Up to 30 Days 30-90 Days Greater than 90 Days Total December 31, 2022 Repurchase agreements: U.S. Treasury $ 3,735,061 $ — $ — $ — $ 3,735,061 Residential mortgage-backed securities 925,580 — — — 925,580 Total borrowings $ 4,660,641 $ — $ — $ — $ 4,660,641 Gross amount of recognized liabilities for repurchase agreements $ 4,660,641 Amounts related to agreements not included in offsetting disclosures above $ — December 31, 2021 Repurchase agreements: U.S. Treasury $ 1,342,591 $ — $ — $ — $ 1,342,591 Residential mortgage-backed securities 1,398,208 — — — 1,398,208 Total borrowings $ 2,740,799 $ — $ — $ — $ 2,740,799 Gross amount of recognized liabilities for repurchase agreements $ 2,740,799 Amounts related to agreements not included in offsetting disclosures above $ —

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
Fair Value Measurements (Tables)	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Financial Assets and Financial Liabilities Measured at Fair Value on a Recurring Basis	The following tables summarize financial assets and financial liabilities measured at fair value on a recurring basis as of December 31, 2022 and 2021, segregated by the level of the valuation inputs within the fair value hierarchy utilized to measure fair value: Level 1 Level 2 Level 3 Total 2022 Securities available for sale: U.S. Treasury $ 5,051,587 $ — $ — $ 5,051,587 Residential mortgage-backed securities — 6,376,236 — 6,376,236 States and political subdivisions — 6,773,355 — 6,773,355 Other — 42,427 — 42,427 Trading account securities: U.S. Treasury 25,879 — — 25,879 States and political subdivisions — 2,166 — 2,166 Derivative assets: Interest rate swaps, caps and floors — 86,793 — 86,793 Commodity swaps and options — 106,685 — 106,685 Foreign currency forward/option contracts 11 — — 11 Derivative liabilities: Interest rate swaps, caps and floors — 95,533 — 95,533 Commodity swaps and options — 105,392 — 105,392 Foreign currency forward/option contracts 11 — — 11 Level 1 Level 2 Level 3 Total 2021 Securities available for sale: U.S. Treasury $ 2,179,433 $ — $ — $ 2,179,433 Residential mortgage-backed securities — 4,066,265 — 4,066,265 States and political subdivisions — 7,636,571 — 7,636,571 Other — 42,359 — 42,359 Trading account securities: U.S. Treasury 24,237 — — 24,237 States and political subdivisions — 925 — 925 Derivative assets: Interest rate swaps, caps and floors — 44,310 — 44,310 Commodity swaps and options — 114,757 — 114,757 Foreign currency forward contracts 33 — — 33 Derivative liabilities: Interest rate swaps, caps and floors — 25,261 — 25,261 Commodity swaps and options — 113,261 — 113,261 Foreign currency forward contracts 55 — — 55
Impaired Loans Remeasured and Reported at Fair Value of Underlying Collateral	The following table presents collateral dependent loans that were remeasured and reported at fair value through a specific allocation of the allowance for credit losses on loans based upon the fair value of the underlying collateral: 2022 2021 2020 Level 2 Carrying value before allocations $ 6,237 $ 1,333 $ 1,559 Specific (allocations) reversals of prior allocations (1,480) 214 (450) Fair value $ 4,757 $ 1,547 $ 1,109 Level 3 Carrying value before allocations $ 8,156 $ 16,074 $ 34,302 Specific (allocations) reversals of prior allocations 625 (5,178) (11,151) Fair value $ 8,781 $ 10,896 $ 23,151
Estimated Fair Values of Financial Instruments	The estimated fair values of financial instruments that are reported at amortized cost in our consolidated balance sheets, segregated by the level of valuation inputs within the fair value hierarchy utilized to measure fair value, were as follows: December 31, 2022 December 31, 2021 Carrying Estimated Carrying Estimated Financial assets: Level 2 inputs: Cash and cash equivalents $ 12,028,132 $ 12,028,132 $ 16,583,000 $ 16,583,000 Securities held to maturity 2,639,083 2,467,865 1,749,179 1,809,143 Cash surrender value of life insurance policies 190,188 190,188 190,139 190,139 Accrued interest receivable 243,682 243,682 179,111 179,111 Level 3 inputs: Loans, net 16,927,348 16,343,417 16,087,731 16,079,454 Financial liabilities: Level 2 inputs: Deposits 43,954,196 43,920,741 42,695,696 41,343,426 Federal funds purchased 51,650 51,650 25,925 25,925 Repurchase agreements 4,660,641 4,660,641 2,740,799 2,740,799 Junior subordinated deferrable interest debentures 123,069 123,712 123,011 123,712 Subordinated notes 99,335 97,014 99,178 111,430 Accrued interest payable 18,444 18,444 3,026 3,026

Operating Segments (Tables)

Operating Segments (Tables)	12 Months Ended
Operating Segments (Tables)	Dec. 31, 2022
Segment Reporting [Abstract]
Summary of Operating Results by Segment	Financial results by operating segment are detailed below. Certain prior period amounts have been reclassified to conform to the current presentation. Frost Wealth Advisors excludes off-balance-sheet managed and custody assets with a total fair value of $43.6 billion, $43.3 billion and $38.6 billion at December 31, 2022, 2021 and 2020. Banking Frost Non-Banks Consolidated 2022 Net interest income (expense) $ 1,295,467 $ 4,645 $ (8,829) $ 1,291,283 Credit loss expense 3,000 — — 3,000 Non-interest income 230,876 175,874 (1,932) 404,818 Non-interest expense 886,421 132,009 5,844 1,024,274 Income (loss) before income taxes 636,922 48,510 (16,605) 668,827 Income tax expense (benefit) 85,127 10,187 (5,637) 89,677 Net income (loss) 551,795 38,323 (10,968) 579,150 Preferred stock dividends — — 6,675 6,675 Net income (loss) available to common shareholders $ 551,795 $ 38,323 $ (17,643) $ 572,475 Revenues from (expenses to) external customers $ 1,526,343 $ 180,519 $ (10,761) $ 1,696,101 Average assets (in millions) $ 51,448 $ 57 $ 8 $ 51,513 Banking Frost Non-Banks Consolidated 2021 Net interest income (expense) $ 989,870 $ 2,138 $ (7,141) $ 984,867 Credit loss expense 54 9 — 63 Non-interest income 220,662 167,442 (1,376) 386,728 Non-interest expense 753,719 122,972 5,303 881,994 Income (loss) before income taxes 456,759 46,599 (13,820) 489,538 Income tax expense (benefit) 41,483 9,786 (4,810) 46,459 Net income (loss) 415,276 36,813 (9,010) 443,079 Preferred stock dividends — — 7,157 7,157 Net income (loss) available to common shareholders $ 415,276 $ 36,813 $ (16,167) $ 435,922 Revenues from (expenses to) external customers $ 1,210,532 $ 169,580 $ (8,517) $ 1,371,595 Average assets (in millions) $ 45,903 $ 70 $ 10 $ 45,983 2020 Net interest income (expense) $ 981,441 $ 2,776 $ (8,216) $ 976,001 Credit loss expense 241,230 — — 241,230 Non-interest income 321,136 145,268 (950) 465,454 Non-interest expense 718,519 123,630 6,755 848,904 Income (loss) before income taxes 342,828 24,414 (15,921) 351,321 Income tax expense (benefit) 20,347 5,127 (5,304) 20,170 Net income (loss) 322,481 19,287 (10,617) 331,151 Preferred stock dividends — — 2,016 2,016 Redemption of preferred stock — — 5,514 5,514 Net income (loss) available to common shareholders $ 322,481 $ 19,287 $ (18,147) $ 323,621 Revenues from (expenses to) external customers $ 1,302,577 $ 148,044 $ (9,166) $ 1,441,455 Average assets (in millions) $ 37,892 $ 59 $ 10 $ 37,961

Condensed Financial Statement_2

Condensed Financial Statements of Parent Company (Tables)	12 Months Ended
Condensed Financial Statements of Parent Company (Tables)	Dec. 31, 2022
Condensed Financial Information Disclosure [Abstract]
Schedule of Condensed Balance Sheets	Condensed Balance Sheets December 31, 2022 2021 Assets: Cash $ 311,944 $ 471,875 Total cash and cash equivalents 311,944 471,875 Investment in subsidiaries 3,065,114 4,222,288 Accrued interest receivable and other assets 1,142 2,228 Total assets $ 3,378,200 $ 4,696,391 Liabilities: Junior subordinated deferrable interest debentures, net of unamortized issuance costs $ 123,069 $ 123,011 Subordinated notes, net of unamortized issuance costs 99,335 99,178 Accrued interest payable and other liabilities 18,568 34,647 Total liabilities 240,972 256,836 Shareholders’ Equity 3,137,228 4,439,555 Total liabilities and shareholders’ equity $ 3,378,200 $ 4,696,391
Schedule of Condensed Statements of Income	Condensed Statements of Income Year Ended December 31, 2022 2021 2020 Income: Dividend income paid by Frost Bank $ 51,711 $ 219,386 $ 298,884 Dividend income paid by non-banks 109 473 736 Interest and other income — 101 446 Total income 51,820 219,960 300,066 Expenses: Interest expense 8,829 7,141 8,216 Salaries and employee benefits 1,605 1,499 1,581 Other 6,316 5,867 6,833 Total expenses 16,750 14,507 16,630 Income before income taxes and equity in undistributed earnings of subsidiaries 35,070 205,453 283,436 Income tax benefit 5,641 4,899 5,406 Equity in undistributed earnings of subsidiaries 538,439 232,727 42,309 Net income 579,150 443,079 331,151 Preferred stock dividends 6,675 7,157 2,016 Redemption of preferred stock — — 5,514 Net income available to common shareholders $ 572,475 $ 435,922 $ 323,621
Schedule of Condensed Statements of Cash Flows	Condensed Statements of Cash Flows Year Ended December 31, 2022 2021 2020 Operating Activities: Net income $ 579,150 $ 443,079 $ 331,151 Adjustments to reconcile net income to net cash provided by operating activities: Equity in undistributed earnings of subsidiaries (538,439) (232,727) (42,309) Stock-based compensation 720 700 770 Net tax benefit from stock-based compensation 472 278 370 Net change in other assets and other liabilities (15,249) 23,890 (8,937) Net cash from operating activities 26,654 235,220 281,045 Investing Activities: Redemption of investment in non-bank subsidiary — 406 — Net cash from investing activities — 406 — Financing Activities: Principal payments on long-term borrowings — (13,403) — Redemption of Series A preferred stock — — (150,000) Proceeds from issuance of Series B preferred stock — — 145,452 Proceeds from stock option exercises 16,659 54,417 12,557 Proceeds from stock-based compensation activities of subsidiaries 17,602 12,053 13,148 Purchase of treasury stock (4,391) (3,864) (15,785) Treasury stock issued to 401(k) stock purchase plan — 1,749 10,307 Cash dividends paid on preferred stock (6,675) (7,157) (2,016) Cash dividends paid on common stock (209,780) (188,786) (180,584) Net cash from financing activities (186,585) (144,991) (166,921) Net change in cash and cash equivalents (159,931) 90,635 114,124 Cash and cash equivalents at beginning of year 471,875 381,240 267,116 Cash and cash equivalents at end of year $ 311,944 $ 471,875 $ 381,240

Summary of Significant Accoun_4

Summary of Significant Accounting Policies (Narrative) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Jan. 01, 2020	Dec. 31, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cash collateral on deposit	$ 3,200	$ 110,300
Foreclosed assets	964	3,400
Real Estate Owned, Valuation Allowance, Provision	$ 0	$ 14	$ 231
Amount of significant concentrations of any properties with write downs from any single geographic region	0%	0%	0%
Cumulative effect of accounting change					$ (29,252)
Minimum [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Range of change in fair value of derivative hedging instrument to be considered highly effective	80%
Maximum [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Range of change in fair value of derivative hedging instrument to be considered highly effective	125%
Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of accounting change				$ (29,300)	$ (29,252)

Summary of Significant Accoun_5

Summary of Significant Accounting Policies (Additional Cash Flow Information) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Accounting Policies [Abstract]
Cash paid for interest	$ 169,020	$ 29,003	$ 49,300
Cash paid for income tax	100,000	39,852	44,140
Exchange of real estate	0	11,036	0
Unsettled securities transactions	94,884	27,032	57,783
Loans foreclosed and transferred to other real estate owned and foreclosed assets	239	3,464	140
Right-of-use lease assets obtained in exchange for lessee operating lease liabilities	31,787	12,854	18,284
Treasury stock issued to 401(k) stock purchase plan	$ 0	$ 1,749	$ 10,307

Summary of Significant Accoun_6

Summary of Significant Accounting Policies (Impact of Adoption of New Accounting Standard Related to CECL) (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Jan. 01, 2020	Dec. 31, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Securities held to maturity, net of allowance for credit losses of $158 in 2022 and $158 in 2021	$ 158	$ 158
Financing Receivable, Allowance for Credit Loss	227,621	248,666
Off-Balance Sheet, Credit Loss, Liability	58,593	50,314	$ 44,152		$ 500
Cumulative effect of accounting change					(29,252)
Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of accounting change				$ (29,300)	(29,252)
Commercial Portfolio Segment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss	104,237	72,091	73,843		51,593
Commercial Portfolio Segment [Member] \| Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of accounting change				(16,798)
Commercial and Industrial Total Energy Loans [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss	18,062	17,217	39,553		37,382
Commercial and Industrial Total Energy Loans [Member] \| Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of accounting change				8,258
Commercial Real Estate Portfolio Segment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss	90,301	144,936	134,892		31,037
Commercial Real Estate Portfolio Segment [Member] \| Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of accounting change				10,680
Total consumer real estate loans [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss	8,004	6,585	7,926		4,113
Total consumer real estate loans [Member] \| Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of accounting change				(1,890)
Consumer Loan [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss	7,017	7,837	6,963		8,042
Consumer Loan [Member] \| Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of accounting change				1,776
Loans Receivable [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss	227,621	248,666	263,177		132,167
Loans Receivable [Member] \| Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of accounting change				2,026
US Treasury [Member] \| Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of accounting change				0
Residential Mortgage Backed Securities [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Securities held to maturity, net of allowance for credit losses of $158 in 2022 and $158 in 2021	0	0
Residential Mortgage Backed Securities [Member] \| Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of accounting change				0
States and Political Subdivisions [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Securities held to maturity, net of allowance for credit losses of $158 in 2022 and $158 in 2021	158	158
States and Political Subdivisions [Member] \| Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of accounting change				(170)
Other [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Securities held to maturity, net of allowance for credit losses of $158 in 2022 and $158 in 2021	0	0
Other [Member] \| Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of accounting change				0
Debt Securities [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Securities held to maturity, net of allowance for credit losses of $158 in 2022 and $158 in 2021	158	158	$ 160		$ 0
Debt Securities [Member] \| Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of accounting change				(170)
Commitments to Extend Credit [Member] \| Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of accounting change				(31,108)
Pre-Adoption Allowance [Member] \| Commercial Portfolio Segment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss				51,593
Pre-Adoption Allowance [Member] \| Commercial and Industrial Total Energy Loans [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss				37,382
Pre-Adoption Allowance [Member] \| Commercial Real Estate Portfolio Segment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss				31,037
Pre-Adoption Allowance [Member] \| Total consumer real estate loans [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss				4,113
Pre-Adoption Allowance [Member] \| Consumer Loan [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss				8,042
Pre-Adoption Allowance [Member] \| Loans Receivable [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss				132,167
Pre-Adoption Allowance [Member] \| US Treasury [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Securities held to maturity, net of allowance for credit losses of $158 in 2022 and $158 in 2021				0
Pre-Adoption Allowance [Member] \| Residential Mortgage Backed Securities [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Securities held to maturity, net of allowance for credit losses of $158 in 2022 and $158 in 2021				0
Pre-Adoption Allowance [Member] \| States and Political Subdivisions [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Securities held to maturity, net of allowance for credit losses of $158 in 2022 and $158 in 2021				0
Pre-Adoption Allowance [Member] \| Other [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Securities held to maturity, net of allowance for credit losses of $158 in 2022 and $158 in 2021				0
Pre-Adoption Allowance [Member] \| Debt Securities [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Securities held to maturity, net of allowance for credit losses of $158 in 2022 and $158 in 2021				0
Pre-Adoption Allowance [Member] \| Commitments to Extend Credit [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Off-Balance Sheet, Credit Loss, Liability				500
Accounting Standards Update 2016-13 [Member] \| Commercial Portfolio Segment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss				21,263
Accounting Standards Update 2016-13 [Member] \| Commercial and Industrial Total Energy Loans [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss				(10,453)
Accounting Standards Update 2016-13 [Member] \| Commercial Real Estate Portfolio Segment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss				(13,519)
Accounting Standards Update 2016-13 [Member] \| Total consumer real estate loans [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss				2,392
Accounting Standards Update 2016-13 [Member] \| Consumer Loan [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss				(2,248)
Accounting Standards Update 2016-13 [Member] \| Loans Receivable [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss				(2,565)
Accounting Standards Update 2016-13 [Member] \| US Treasury [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Securities held to maturity, net of allowance for credit losses of $158 in 2022 and $158 in 2021				0
Accounting Standards Update 2016-13 [Member] \| Residential Mortgage Backed Securities [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Securities held to maturity, net of allowance for credit losses of $158 in 2022 and $158 in 2021				0
Accounting Standards Update 2016-13 [Member] \| States and Political Subdivisions [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Securities held to maturity, net of allowance for credit losses of $158 in 2022 and $158 in 2021				215
Accounting Standards Update 2016-13 [Member] \| Other [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Securities held to maturity, net of allowance for credit losses of $158 in 2022 and $158 in 2021				0
Accounting Standards Update 2016-13 [Member] \| Debt Securities [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Securities held to maturity, net of allowance for credit losses of $158 in 2022 and $158 in 2021	$ 0	$ 0		215
Accounting Standards Update 2016-13 [Member] \| Commitments to Extend Credit [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Off-Balance Sheet, Credit Loss, Liability				39,377
Post-Adoption Allowance [Member] \| Commercial Portfolio Segment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss				72,856
Post-Adoption Allowance [Member] \| Commercial and Industrial Total Energy Loans [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss				26,929
Post-Adoption Allowance [Member] \| Commercial Real Estate Portfolio Segment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss				17,518
Post-Adoption Allowance [Member] \| Total consumer real estate loans [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss				6,505
Post-Adoption Allowance [Member] \| Consumer Loan [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss				5,794
Post-Adoption Allowance [Member] \| Loans Receivable [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss				129,602
Post-Adoption Allowance [Member] \| US Treasury [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Securities held to maturity, net of allowance for credit losses of $158 in 2022 and $158 in 2021				0
Post-Adoption Allowance [Member] \| Residential Mortgage Backed Securities [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Securities held to maturity, net of allowance for credit losses of $158 in 2022 and $158 in 2021				0
Post-Adoption Allowance [Member] \| States and Political Subdivisions [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Securities held to maturity, net of allowance for credit losses of $158 in 2022 and $158 in 2021				215
Post-Adoption Allowance [Member] \| Other [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Securities held to maturity, net of allowance for credit losses of $158 in 2022 and $158 in 2021				0
Post-Adoption Allowance [Member] \| Debt Securities [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Securities held to maturity, net of allowance for credit losses of $158 in 2022 and $158 in 2021				215
Post-Adoption Allowance [Member] \| Commitments to Extend Credit [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Off-Balance Sheet, Credit Loss, Liability				$ 39,877

Securities (Narrative) (Detail)

Securities (Narrative) (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Schedule Of Marketable Securities [Line Items]
Net unamortized, unrealized gain on transferred securities included in accumulated other comprehensive income, pre tax	$ 1,800	$ 2,500
Net unamortized, unrealized gain on transferred securities included in accumulated other comprehensive income, net of tax	1,400	2,000
Debt Securities, Held-to-maturity, 90 Days or More Past Due, Still Accruing	0
Securities held to maturity, net of allowance for credit losses of $158 in 2022 and $158 in 2021	$ 158	158
Percent Municipal Bond Portfolio Issued By Political Subdivision Or Agencies Within State Of Texas Guaranteed By Texas Permanent School Fund Or Have Been Pre-Refunded	75.90%
Debt Securities, Available-for-sale, Allowance for Credit Loss	$ 0	0
Debt Securities [Member]
Schedule Of Marketable Securities [Line Items]
Securities held to maturity, net of allowance for credit losses of $158 in 2022 and $158 in 2021	158	158	$ 160	$ 0
Held-to-maturity Securities [Member]
Schedule Of Marketable Securities [Line Items]
Carry value of securities pledged	256,300	642,300
Accrued interest receivable	30,200	18,400
Guaranteed by the Texas PSF [Member] \| Debt Securities [Member]
Schedule Of Marketable Securities [Line Items]
Securities held to maturity, net of allowance for credit losses of $158 in 2022 and $158 in 2021	0
Pre-Refunded [Member] \| Debt Securities [Member]
Schedule Of Marketable Securities [Line Items]
Securities held to maturity, net of allowance for credit losses of $158 in 2022 and $158 in 2021	0
Available-for-sale Securities [Member]
Schedule Of Marketable Securities [Line Items]
Carry value of securities pledged	8,000,000	5,800,000
Accrued interest receivable	$ 140,600	$ 120,500

Securities (Year End Securities

Securities (Year End Securities Held to Maturity) (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Schedule of Investments [Line Items]
Held to Maturity, Amortized Cost	$ 2,639,241	$ 1,749,337
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	13,048	59,907
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	184,424	101
Debt Securities, Held to Maturity, Estimated Fair Value	2,467,865	1,809,143
Debt Securities, Held-to-maturity, Allowance for Credit Loss	(158)	(158)
Securities held to maturity, net of allowance for credit losses of $158 in 2022 and $158 in 2021	2,639,083	1,749,179
Residential Mortgage Backed Securities [Member]
Schedule of Investments [Line Items]
Held to Maturity, Amortized Cost	526,122	527,264
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	0	18,766
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	65,322	0
Debt Securities, Held to Maturity, Estimated Fair Value	460,800	546,030
Debt Securities, Held-to-maturity, Allowance for Credit Loss	0	0
Securities held to maturity, net of allowance for credit losses of $158 in 2022 and $158 in 2021	526,122	527,264
States and Political Subdivisions [Member]
Schedule of Investments [Line Items]
Held to Maturity, Amortized Cost	2,111,619	1,220,573
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	13,048	41,141
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	119,033	101
Debt Securities, Held to Maturity, Estimated Fair Value	2,005,634	1,261,613
Debt Securities, Held-to-maturity, Allowance for Credit Loss	(158)	(158)
Securities held to maturity, net of allowance for credit losses of $158 in 2022 and $158 in 2021	2,111,461	1,220,415
Other [Member]
Schedule of Investments [Line Items]
Held to Maturity, Amortized Cost	1,500	1,500
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	0	0
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	69	0
Debt Securities, Held to Maturity, Estimated Fair Value	1,431	1,500
Debt Securities, Held-to-maturity, Allowance for Credit Loss	0	0
Securities held to maturity, net of allowance for credit losses of $158 in 2022 and $158 in 2021	$ 1,500	$ 1,500

Securities (Securities Moody's

Securities (Securities Moody's and Standard & Poor's Bond Rating) (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Schedule of Held-to-maturity Securities [Line Items]
Held to Maturity, Amortized Cost	$ 2,639,241	$ 1,749,337
States and Political Subdivisions [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to Maturity, Amortized Cost	2,111,619	1,220,573
States and Political Subdivisions [Member] \| Not Guaranteed or Pre-Refunded [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to Maturity, Amortized Cost	567,216
States and Political Subdivisions [Member] \| Guaranteed by the Texas PSF [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to Maturity, Amortized Cost	1,422,442
States and Political Subdivisions [Member] \| Pre-Refunded [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to Maturity, Amortized Cost	121,961
Other [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to Maturity, Amortized Cost	1,500	$ 1,500
Aaa/AAA [Member] \| States and Political Subdivisions [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to Maturity, Amortized Cost	1,817,604
Aaa/AAA [Member] \| States and Political Subdivisions [Member] \| Not Guaranteed or Pre-Refunded [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to Maturity, Amortized Cost	273,201
Aaa/AAA [Member] \| States and Political Subdivisions [Member] \| Guaranteed by the Texas PSF [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to Maturity, Amortized Cost	1,422,442
Aaa/AAA [Member] \| States and Political Subdivisions [Member] \| Pre-Refunded [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to Maturity, Amortized Cost	121,961
Aaa/AAA [Member] \| Other [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to Maturity, Amortized Cost	0
Aa/AA [Member] \| States and Political Subdivisions [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to Maturity, Amortized Cost	294,015
Aa/AA [Member] \| States and Political Subdivisions [Member] \| Not Guaranteed or Pre-Refunded [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to Maturity, Amortized Cost	294,015
Aa/AA [Member] \| States and Political Subdivisions [Member] \| Guaranteed by the Texas PSF [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to Maturity, Amortized Cost	0
Aa/AA [Member] \| States and Political Subdivisions [Member] \| Pre-Refunded [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to Maturity, Amortized Cost	0
Aa/AA [Member] \| Other [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to Maturity, Amortized Cost	0
Not rated [Member] \| States and Political Subdivisions [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to Maturity, Amortized Cost	0
Not rated [Member] \| States and Political Subdivisions [Member] \| Not Guaranteed or Pre-Refunded [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to Maturity, Amortized Cost	0
Not rated [Member] \| States and Political Subdivisions [Member] \| Guaranteed by the Texas PSF [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to Maturity, Amortized Cost	0
Not rated [Member] \| States and Political Subdivisions [Member] \| Pre-Refunded [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to Maturity, Amortized Cost	0
Not rated [Member] \| Other [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held to Maturity, Amortized Cost	$ 1,500

Securities (Securities Held to

Securities (Securities Held to Maturity Allowance for Credit Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Jan. 01, 2020	Dec. 31, 2019
Schedule of Held-to-maturity Securities [Line Items]
Securities held to maturity, net of allowance for credit losses of $158 in 2022 and $158 in 2021	$ 158	$ 158
Debt Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Securities held to maturity, net of allowance for credit losses of $158 in 2022 and $158 in 2021	158	158	$ 160		$ 0
Debt Securities, Held-to-maturity, Allowance for Credit Loss, Period Increase (Decrease)	0	(2)	$ (55)
Debt Securities [Member] \| Accounting Standards Update 2016-13 [Member]
Schedule of Held-to-maturity Securities [Line Items]
Securities held to maturity, net of allowance for credit losses of $158 in 2022 and $158 in 2021	$ 0	$ 0		$ 215

Securities (Securities Availabl

Securities (Securities Available for Sale) (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	$ 19,908,432	$ 13,445,888
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	17,158	518,805
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	1,681,985	40,065
Debt Securities, Available-for-sale, Allowance for Credit Loss	0	0
Debt Securities, Available-for-sale	18,243,605	13,924,628
US Treasury [Member]
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	5,450,546	2,165,702
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	0	23,333
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	398,959	9,602
Debt Securities, Available-for-sale, Allowance for Credit Loss	0	0
Debt Securities, Available-for-sale	5,051,587	2,179,433
Residential Mortgage Backed Securities [Member]
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	7,316,824	4,059,692
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	8,050	31,662
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	948,638	25,089
Debt Securities, Available-for-sale, Allowance for Credit Loss	0	0
Debt Securities, Available-for-sale	6,376,236	4,066,265
States and Political Subdivisions [Member]
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	7,098,635	7,178,135
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	9,108	463,810
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	334,388	5,374
Debt Securities, Available-for-sale, Allowance for Credit Loss	0	0
Debt Securities, Available-for-sale	6,773,355	7,636,571
Other [Member]
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	42,427	42,359
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	0	0
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	0	0
Debt Securities, Available-for-sale, Allowance for Credit Loss	0	0
Debt Securities, Available-for-sale	$ 42,427	$ 42,359

Securities (Year End Securiti_2

Securities (Year End Securities with Unrealized Losses Segregated by Length of Impairment) (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Schedule of Available-for-Sale Securities [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 9,200,946
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	545,779
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	6,217,041
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	1,136,206
Available for Sale, Total Estimated Fair Value	15,417,987
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	1,681,985	$ 40,065
US Treasury [Member]
Schedule of Available-for-Sale Securities [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	2,012,129
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	63,515
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	3,039,458
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	335,444
Available for Sale, Total Estimated Fair Value	5,051,587
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	398,959	9,602
Residential Mortgage Backed Securities [Member]
Schedule of Available-for-Sale Securities [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	3,265,658
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	345,307
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	2,495,906
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	603,331
Available for Sale, Total Estimated Fair Value	5,761,564
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	948,638	25,089
States and Political Subdivisions [Member]
Schedule of Available-for-Sale Securities [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	3,923,159
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	136,957
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	681,677
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	197,431
Available for Sale, Total Estimated Fair Value	4,604,836
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	$ 334,388	$ 5,374

Securities (Amortized Cost and

Securities (Amortized Cost and Estimated Fair Value of Securities Excluding Trading Securities Presented by Contractual Maturity) (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Schedule of Available-for-Sale Securities [Line Items]
Held to Maturity, Due in one year or less, Amortized Cost	$ 123,591
Held to Maturity, Due after one year through five years, Amortized Cost	25,839
Held to Maturity, Due after five years through ten years, Amortized Cost	522,356
Held to Maturity, Due after ten years, Amortized Cost	1,967,455
Held to Maturity, Amortized Cost	2,639,241	$ 1,749,337
Held to Maturity, Due in one year or less, Estimated Fair Value	123,505
Held to Maturity, Due after one year through five years, Estimated Fair Value	25,723
Held to Maturity, Due after five years through ten years, Estimated Fair Value	459,247
Held to Maturity, Due after ten years, Estimated Fair Value	1,859,390
Held to Maturity, Estimated Fair Value	2,467,865	1,809,143
Available for Sale, Due in one year or less, Amortized Cost	510,848
Available for Sale, Due after one year through five years, Amortized Cost	5,046,852
Available for Sale, Due after five years through ten years, Amortized Cost	2,387,656
Available for Sale, Due after ten years, Amortized Cost	11,920,649
Debt Securities, Available-for-sale, Amortized Cost, Total	19,908,432	13,445,888
Available for Sale, Due in one year or less, Estimated Fair Value	502,257
Available for Sale, Due after one year through five years, Estimated Fair Value	4,901,648
Available for Sale, Due after five years through ten years, Estimated Fair Value	2,179,267
Available for Sale, Due after ten years, Estimated Fair Value	10,618,006
Debt Securities, Available-for-sale	18,243,605	13,924,628
US Treasury [Member]
Schedule of Available-for-Sale Securities [Line Items]
Available for Sale, Due in one year or less, Amortized Cost	249,363
Available for Sale, Due after one year through five years, Amortized Cost	3,574,630
Available for Sale, Due after five years through ten years, Amortized Cost	1,434,504
Available for Sale, Due after ten years, Amortized Cost	192,049
Debt Securities, Available-for-sale, Amortized Cost, Total	5,450,546	2,165,702
Available for Sale, Due in one year or less, Estimated Fair Value	240,361
Available for Sale, Due after one year through five years, Estimated Fair Value	3,424,023
Available for Sale, Due after five years through ten years, Estimated Fair Value	1,244,812
Available for Sale, Due after ten years, Estimated Fair Value	142,391
Debt Securities, Available-for-sale	5,051,587	2,179,433
Residential Mortgage Backed Securities [Member]
Schedule of Available-for-Sale Securities [Line Items]
Held to Maturity, Due in one year or less, Amortized Cost	0
Held to Maturity, Due after one year through five years, Amortized Cost	0
Held to Maturity, Due after five years through ten years, Amortized Cost	514,059
Held to Maturity, Due after ten years, Amortized Cost	12,063
Held to Maturity, Amortized Cost	526,122	527,264
Held to Maturity, Due in one year or less, Estimated Fair Value	0
Held to Maturity, Due after one year through five years, Estimated Fair Value	0
Held to Maturity, Due after five years through ten years, Estimated Fair Value	450,961
Held to Maturity, Due after ten years, Estimated Fair Value	9,839
Held to Maturity, Estimated Fair Value	460,800	546,030
Available for Sale, Due in one year or less, Amortized Cost	8
Available for Sale, Due after one year through five years, Amortized Cost	7,729
Available for Sale, Due after five years through ten years, Amortized Cost	16,025
Available for Sale, Due after ten years, Amortized Cost	7,293,062
Debt Securities, Available-for-sale, Amortized Cost, Total	7,316,824	4,059,692
Available for Sale, Due in one year or less, Estimated Fair Value	8
Available for Sale, Due after one year through five years, Estimated Fair Value	7,527
Available for Sale, Due after five years through ten years, Estimated Fair Value	15,892
Available for Sale, Due after ten years, Estimated Fair Value	6,352,809
Debt Securities, Available-for-sale	6,376,236	4,066,265
States and Political Subdivisions [Member]
Schedule of Available-for-Sale Securities [Line Items]
Held to Maturity, Due in one year or less, Amortized Cost	123,591
Held to Maturity, Due after one year through five years, Amortized Cost	24,339
Held to Maturity, Due after five years through ten years, Amortized Cost	8,297
Held to Maturity, Due after ten years, Amortized Cost	1,955,392
Held to Maturity, Amortized Cost	2,111,619	1,220,573
Held to Maturity, Due in one year or less, Estimated Fair Value	123,505
Held to Maturity, Due after one year through five years, Estimated Fair Value	24,292
Held to Maturity, Due after five years through ten years, Estimated Fair Value	8,286
Held to Maturity, Due after ten years, Estimated Fair Value	1,849,551
Held to Maturity, Estimated Fair Value	2,005,634	1,261,613
Available for Sale, Due in one year or less, Amortized Cost	261,477
Available for Sale, Due after one year through five years, Amortized Cost	1,464,493
Available for Sale, Due after five years through ten years, Amortized Cost	937,127
Available for Sale, Due after ten years, Amortized Cost	4,435,538
Debt Securities, Available-for-sale, Amortized Cost, Total	7,098,635	7,178,135
Available for Sale, Due in one year or less, Estimated Fair Value	261,888
Available for Sale, Due after one year through five years, Estimated Fair Value	1,470,098
Available for Sale, Due after five years through ten years, Estimated Fair Value	918,563
Available for Sale, Due after ten years, Estimated Fair Value	4,122,806
Debt Securities, Available-for-sale	6,773,355	7,636,571
Other [Member]
Schedule of Available-for-Sale Securities [Line Items]
Held to Maturity, Due in one year or less, Amortized Cost	0
Held to Maturity, Due after one year through five years, Amortized Cost	1,500
Held to Maturity, Due after five years through ten years, Amortized Cost	0
Held to Maturity, Due after ten years, Amortized Cost	0
Held to Maturity, Amortized Cost	1,500	1,500
Held to Maturity, Due in one year or less, Estimated Fair Value	0
Held to Maturity, Due after one year through five years, Estimated Fair Value	1,431
Held to Maturity, Due after five years through ten years, Estimated Fair Value	0
Held to Maturity, Due after ten years, Estimated Fair Value	0
Held to Maturity, Estimated Fair Value	1,431	1,500
Available for Sale, Due in one year or less, Amortized Cost	0
Available for Sale, Due after one year through five years, Amortized Cost	0
Available for Sale, Due after five years through ten years, Amortized Cost	0
Available for Sale, Due after ten years, Amortized Cost	0
Debt Securities, Available-for-sale, Amortized Cost, Total	42,427	42,359
Available for Sale, Due in one year or less, Estimated Fair Value	0
Available for Sale, Due after one year through five years, Estimated Fair Value	0
Available for Sale, Due after five years through ten years, Estimated Fair Value	0
Available for Sale, Due after ten years, Estimated Fair Value	0
Debt Securities, Available-for-sale	$ 42,427	$ 42,359

Securities (Sales of Securities

Securities (Sales of Securities Available for Sale) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Investments, Debt and Equity Securities [Abstract]
Proceeds from sales	$ 0	$ 1,999,891	$ 1,162,352
Gross realized gains	0	69	108,989
Gross realized losses	0	0	0
Tax benefit (expense) related to securities gains/losses	$ 0	$ (14)	$ (22,888)

Securities Securities - (Premiu

Securities Securities - (Premium Amortization and Discount Accretion Included in Income on Securities) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Investments, Debt and Equity Securities [Abstract]
Premium amortization	$ (110,997)	$ (121,994)	$ (126,210)
Discount accretion	13,597	2,752	2,425
Net (premium amortization) discount accretion	$ (97,400)	$ (119,242)	$ (123,785)

Securities (Year End Trading Ac

Securities (Year End Trading Account Securities at Estimated Fair Value) (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Debt and Equity Securities, FV-NI [Line Items]
Trading account securities	$ 28,045	$ 25,162
US Treasury [Member]
Debt and Equity Securities, FV-NI [Line Items]
Trading account securities	25,879	24,237
States and Political Subdivisions [Member]
Debt and Equity Securities, FV-NI [Line Items]
Trading account securities	$ 2,166	$ 925

Securities (Net Gains and Losse

Securities (Net Gains and Losses on Trading Account Securities) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Investments, Debt and Equity Securities [Abstract]
Net gain on sales transactions	$ 3,129	$ 1,014	$ 1,102
Net mark-to-market gains (losses)	(230)	(75)	85
Net gain on trading account securities	$ 2,899	$ 939	$ 1,187

Loans (Narrative) (Detail)

Loans (Narrative) (Detail) $ in Thousands	12 Months Ended
Loans (Narrative) (Detail) $ in Thousands	Dec. 31, 2022 USD ($) Grade	Dec. 31, 2021 USD ($) Grade	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Concentration of loans in a single industry in excess of ten percent	0%	0%
Maximum percentage loan related to single industry	10%	10%
U.S. dollar denominated loans and commitments to borrowers in Mexico	$ 0	$ 0
Commercial and industrial loans related to overdraft for correspondent bank customer	$ 10,300	$ 7,800
Financing Receivable, Threshold Period Past Due	90 days
Number of days past due for payment of interest on loans, minimum	120 days
Texas Leading Index economic condition indicator	129.7	135.7
Financing Receivable, Allowance for Credit Loss	$ 227,621	$ 248,666
Loans Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accrued interest receivable	$ 68,700	$ 40,000
Commercial and Industrial Total Energy Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of total energy loans to total loans	5.40%	6.60%
Weighted Average Risk Grade \| Grade	5.67	6.06
Financing Receivable, Allowance for Credit Loss	$ 18,062	$ 17,217	$ 39,553	$ 37,382
Commercial and Industrial Total Energy Loans [Member] \| Risk Grade One To Eight [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Risk Grade \| Grade	5.44	5.78
Non Accrual Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Additional interest that would have been recognized on non-accrual loans, net of tax	$ 1,700	$ 1,800	2,900
Grade 12 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
General percentage of valuation allowance in excess of principal balance, maximum	30%
Grade 13 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
General percentage of valuation allowance in excess of principal balance, minimum	30%
Commercial Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Risk Grade \| Grade	6.39	6.22
Financing Receivable, Allowance for Credit Loss	$ 104,237	$ 72,091	73,843	51,593
Commercial Portfolio Segment [Member] \| Risk Grade One To Eight [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Risk Grade \| Grade	6.24	6.01
Commercial and Industrial, Other Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of days past due for payment of interest on loans, minimum	180 days
Commercial Real Estate Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Risk Grade \| Grade	7.10	7.19
Financing Receivable, Allowance for Credit Loss	$ 90,301	$ 144,936	134,892	31,037
Commercial Real Estate Buildings Land And Other Financing Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Risk Grade \| Grade	7.09	7.22
Commercial Real Estate Buildings Land And Other Financing Receivable [Member] \| Risk Grade One To Eight [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Risk Grade \| Grade	6.94	6.91
Construction Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Risk Grade \| Grade	7.12	7.06
Construction Loans [Member] \| Risk Grade One To Eight [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Risk Grade \| Grade	7.04	6.99
Consumer Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Allowance for Credit Loss	$ 7,017	$ 7,837	6,963	$ 8,042
Paycheck Protection Program [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Allowance for Credit Loss	0	$ 0	$ 0
Commitments to Extend Credit [Member] \| Commercial and Industrial Total Energy Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unfunded balances	997,100
Standby Letters of Credit [Member] \| Commercial and Industrial Total Energy Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unfunded balances	$ 103,400

Loans (Loans) (Detail)

Loans (Loans) (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned discounts	$ 17,154,969	$ 16,336,397
Commercial Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned discounts	5,674,798	5,364,954
Energy Production [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned discounts	696,570	878,436
Energy Service [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned discounts	133,542	105,901
Energy Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned discounts	95,617	93,455
Commercial and Industrial Total Energy Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned discounts	925,729	1,077,792
Paycheck Protection Program [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned discounts	34,852	428,882
Commercial mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned discounts	6,168,910	5,867,062
Construction Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned discounts	1,477,247	1,304,271
Commercial land loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned discounts	537,168	405,277
Commercial Real Estate Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned discounts	8,183,325	7,576,610
Home Equity Line of Credit [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned discounts	691,841	519,098
Home Equity Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned discounts	449,507	324,157
Home Improvement Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned discounts	577,377	428,069
Other consumer real estate loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned discounts	124,814	139,466
Total consumer real estate loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned discounts	1,843,539	1,410,790
Real Estate Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned discounts	10,026,864	8,987,400
Consumer Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned discounts	$ 492,726	$ 477,369

Loans (Activities in Related Pa

Loans (Activities in Related Party Loans) (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($)
Receivables [Abstract]
Balance outstanding at December 31, 2021	$ 350,538
Principal additions	337,700
Principal payments	(294,857)
Other changes	(2,126)
Balance outstanding at December 31, 2022	$ 391,255

Loans (Non-Accrual Loans, Segre

Loans (Non-Accrual Loans, Segregated by Class of Loans) (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Non Accrual Loans Segregated By Class Of Loans [Line Items]
Non-accrual loans	$ 37,833	$ 53,713
Financing Receivable, Nonaccrual, No Allowance	18,571	27,202
Commercial Portfolio Segment [Member]
Non Accrual Loans Segregated By Class Of Loans [Line Items]
Non-accrual loans	18,130	22,582
Financing Receivable, Nonaccrual, No Allowance	8,514	4,701
Commercial and Industrial Total Energy Loans [Member]
Non Accrual Loans Segregated By Class Of Loans [Line Items]
Non-accrual loans	15,224	14,433
Financing Receivable, Nonaccrual, No Allowance	7,139	8,533
Commercial Real Estate, Buildings, Land and Other [Member]
Non Accrual Loans Segregated By Class Of Loans [Line Items]
Non-accrual loans	3,552	15,297
Financing Receivable, Nonaccrual, No Allowance	1,991	13,817
Construction Loans [Member]
Non Accrual Loans Segregated By Class Of Loans [Line Items]
Non-accrual loans	0	948
Financing Receivable, Nonaccrual, No Allowance	0	0
Total consumer real estate loans [Member]
Non Accrual Loans Segregated By Class Of Loans [Line Items]
Non-accrual loans	927	440
Financing Receivable, Nonaccrual, No Allowance	927	138
Consumer Loan [Member]
Non Accrual Loans Segregated By Class Of Loans [Line Items]
Non-accrual loans	0	13
Financing Receivable, Nonaccrual, No Allowance	$ 0	$ 13

Loans (Non-Accrual Loans, Seg_2

Loans (Non-Accrual Loans, Segregated by Class of Loan and Year of Origination) (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Loans and Leases Receivable Disclosure [Line Items]
Non-accrual loans	$ 37,833	$ 53,713
Commercial Portfolio Segment [Member]
Loans and Leases Receivable Disclosure [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	1,703,185	1,630,524
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	657,039	693,324
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	498,213	392,408
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	241,997	214,163
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	138,541	150,922
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	195,754	143,292
Financing Receivable, Revolving	2,170,182	2,075,632
Non-accrual loans	18,130	22,582
Commercial and Industrial Total Energy Loans [Member]
Loans and Leases Receivable Disclosure [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	352,224	475,023
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	100,862	9,539
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	5,312	20,991
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	8,659	9,480
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	3,078	3,110
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	2,913	5,638
Financing Receivable, Revolving	408,022	483,020
Non-accrual loans	15,224	14,433
Commercial Real Estate, Buildings, Land and Other [Member]
Loans and Leases Receivable Disclosure [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	1,901,888	1,761,554
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	1,528,173	1,257,055
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	1,009,197	1,008,366
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	745,031	632,020
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	410,327	612,767
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	882,021	825,249
Financing Receivable, Revolving	120,958	59,595
Non-accrual loans	3,552	15,297
Construction Loans [Member]
Loans and Leases Receivable Disclosure [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	666,024	693,192
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	491,563	268,080
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	130,888	178,226
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	2,236	2,339
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	486	484
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,726	1,930
Financing Receivable, Revolving	181,180	160,020
Non-accrual loans	0	948
Total consumer real estate loans [Member]
Loans and Leases Receivable Disclosure [Line Items]
Non-accrual loans	927	440
Consumer Loan [Member]
Loans and Leases Receivable Disclosure [Line Items]
Non-accrual loans	0	13
Nonperforming Financial Instruments [Member]
Loans and Leases Receivable Disclosure [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	6,301	6,687
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	1,510	5,111
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	1,161	13,851
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	4,845	3,959
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	1,473	2,795
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,700	3,423
Financing Receivable, Revolving	10,604	11,566
Financing Receivable, Revolving, Converted to Term Loan	10,239	6,321
Nonperforming Financial Instruments [Member] \| Commercial Portfolio Segment [Member]
Loans and Leases Receivable Disclosure [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0	636
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	1,252	3,856
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	1,089	5,047
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	3,242	1,820
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	1,197	765
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	191	353
Financing Receivable, Revolving	2,973	4,635
Financing Receivable, Revolving, Converted to Term Loan	8,186	5,470
Nonperforming Financial Instruments [Member] \| Commercial and Industrial Total Energy Loans [Member]
Loans and Leases Receivable Disclosure [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	4,657	0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	0	0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	72	5,358
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	1,386	1,325
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	10	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	0	0
Financing Receivable, Revolving	7,631	6,931
Financing Receivable, Revolving, Converted to Term Loan	1,468	819
Nonperforming Financial Instruments [Member] \| Commercial Real Estate, Buildings, Land and Other [Member]
Loans and Leases Receivable Disclosure [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	1,644	6,038
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	0	307
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	0	3,446
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	217	814
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	266	2,030
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,425	2,662
Financing Receivable, Revolving	0	0
Financing Receivable, Revolving, Converted to Term Loan	0	0
Nonperforming Financial Instruments [Member] \| Construction Loans [Member]
Loans and Leases Receivable Disclosure [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0	0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	0	948
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	0	0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	0	0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	0	0
Financing Receivable, Revolving	0	0
Financing Receivable, Revolving, Converted to Term Loan	0	0
Nonperforming Financial Instruments [Member] \| Total consumer real estate loans [Member]
Loans and Leases Receivable Disclosure [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0	0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	258	0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	0	0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	0	0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	84	408
Financing Receivable, Revolving	0	0
Financing Receivable, Revolving, Converted to Term Loan	585	32
Nonperforming Financial Instruments [Member] \| Consumer Loan [Member]
Loans and Leases Receivable Disclosure [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0	13
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	0	0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	0	0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	0	0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	0	0
Financing Receivable, Revolving	0	0
Financing Receivable, Revolving, Converted to Term Loan	$ 0	$ 0

Loans (Age Analysis of Past Due

Loans (Age Analysis of Past Due Loans, Segregated by Class of Loans) (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Financing Receivable, Past Due [Line Items]
Total loans	$ 17,154,969	$ 16,336,397
Accruing Loans 90 or More Days Past Due	27,800
Commercial Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Total loans	5,674,798	5,364,954
Accruing Loans 90 or More Days Past Due	5,560
Commercial and Industrial Total Energy Loans [Member]
Financing Receivable, Past Due [Line Items]
Total loans	925,729	1,077,792
Accruing Loans 90 or More Days Past Due	0
Paycheck Protection Program [Member]
Financing Receivable, Past Due [Line Items]
Total loans	34,852	428,882
Accruing Loans 90 or More Days Past Due	13,867
Commercial Real Estate, Buildings, Land and Other [Member]
Financing Receivable, Past Due [Line Items]
Total loans	6,706,078	6,272,339
Accruing Loans 90 or More Days Past Due	5,664
Construction Loans [Member]
Financing Receivable, Past Due [Line Items]
Total loans	1,477,247	1,304,271
Accruing Loans 90 or More Days Past Due	0
Total consumer real estate loans [Member]
Financing Receivable, Past Due [Line Items]
Total loans	1,843,539	1,410,790
Accruing Loans 90 or More Days Past Due	2,398
Consumer Loan [Member]
Financing Receivable, Past Due [Line Items]
Total loans	492,726	477,369
Accruing Loans 90 or More Days Past Due	311
Financing Receivables, 30 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	80,940
Financing Receivables, 30 to 89 Days Past Due [Member] \| Commercial Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	36,167
Financing Receivables, 30 to 89 Days Past Due [Member] \| Commercial and Industrial Total Energy Loans [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	2,880
Financing Receivables, 30 to 89 Days Past Due [Member] \| Paycheck Protection Program [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	5,321
Financing Receivables, 30 to 89 Days Past Due [Member] \| Commercial Real Estate, Buildings, Land and Other [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	23,561
Financing Receivables, 30 to 89 Days Past Due [Member] \| Construction Loans [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	0
Financing Receivables, 30 to 89 Days Past Due [Member] \| Total consumer real estate loans [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	7,856	4,877
Financing Receivables, 30 to 89 Days Past Due [Member] \| Consumer Loan [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	5,155	4,185
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	43,270
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] \| Commercial Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	12,853
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] \| Commercial and Industrial Total Energy Loans [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	7,680
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] \| Paycheck Protection Program [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	13,867
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] \| Commercial Real Estate, Buildings, Land and Other [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	5,869
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] \| Construction Loans [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] \| Total consumer real estate loans [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	2,690	2,513
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] \| Consumer Loan [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	311	1,076
Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	124,210
Financial Asset, Past Due \| Commercial Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	49,020
Financial Asset, Past Due \| Commercial and Industrial Total Energy Loans [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	10,560
Financial Asset, Past Due \| Paycheck Protection Program [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	19,188
Financial Asset, Past Due \| Commercial Real Estate, Buildings, Land and Other [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	29,430
Financial Asset, Past Due \| Construction Loans [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	0
Financial Asset, Past Due \| Total consumer real estate loans [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	10,546	7,390
Financial Asset, Past Due \| Consumer Loan [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	5,466	5,261
Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	17,030,759
Financial Asset, Not Past Due \| Commercial Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	5,625,778
Financial Asset, Not Past Due \| Commercial and Industrial Total Energy Loans [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	915,169
Financial Asset, Not Past Due \| Paycheck Protection Program [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	15,664
Financial Asset, Not Past Due \| Commercial Real Estate, Buildings, Land and Other [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	6,676,648
Financial Asset, Not Past Due \| Construction Loans [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	1,477,247
Financial Asset, Not Past Due \| Total consumer real estate loans [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	1,832,993	1,403,400
Financial Asset, Not Past Due \| Consumer Loan [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 487,260	$ 472,108

Loans (Troubled Debt Restructur

Loans (Troubled Debt Restructurings) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance at Restructure	$ 1,155	$ 7,017	$ 17,524
Balance at Year-end	1,051	3,745	8,552
Commercial Portfolio Segment [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance at Restructure	0	1,312	3,661
Balance at Year-end	0	1,162	192
Commercial and Industrial Total Energy Loans [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance at Restructure	0	3,817	2,432
Balance at Year-end	0	721	2,421
Commercial Real Estate, Buildings, Land and Other [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance at Restructure	1,155	1,888	9,310
Balance at Year-end	1,051	1,862	4,922
Construction Loans [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance at Restructure	0	0	1,017
Balance at Year-end	0	0	1,017
Total consumer real estate loans [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance at Restructure	0	0	0
Balance at Year-end	0	0	0
Consumer Loan [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Balance at Restructure	0	0	1,104
Balance at Year-end	$ 0	$ 0	$ 0

Loans Loans (Restructured Loans

Loans Loans (Restructured Loans Past Due in Excess of 90 Days) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($) Item	Dec. 31, 2021 USD ($) Item	Dec. 31, 2020 USD ($) Item
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number Of restructured loans past due in excess of 90 days at period-end \| Item	0	2	1
Dollar amount of loans previously restructured during the last year in excess of 90 days past due	$ 0	$ 1,027	$ 2,008
Restructured loans on non-accrual status at period end	1,051	3,439	8,552
Chare-offs of restrucured loans recognized in connection with restructuring	0	0	337
Charge-offs of restructured loans recognized on previously restructured loans	723	4,278	3,894
Proceeds from sale of restructured loans	$ 1,070	$ 0	$ 0

Loans (Weighted Average Risk Gr

Loans (Weighted Average Risk Grades for All Commercial Loans by Class) (Detail) $ in Thousands	Dec. 31, 2022 USD ($) Grade	Dec. 31, 2021 USD ($) Grade
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned discounts	$ 17,154,969	$ 16,336,397
Commercial Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	1,703,185	1,630,524
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	657,039	693,324
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	498,213	392,408
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	241,997	214,163
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	138,541	150,922
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	195,754	143,292
Financing Receivable, Revolving	2,170,182	2,075,632
Loans, net of unearned discounts	$ 5,674,798	$ 5,364,954
Weighted Average Risk Grade \| Grade	6.39	6.22
Commercial Portfolio Segment [Member] \| Revolving Credit Facility
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Risk Grade \| Grade	6.26	6.21
Commercial Portfolio Segment [Member] \| Revolving Loans Converted to Term
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Revolving, Converted to Term Loan	$ 69,887	$ 64,689
Weighted Average Risk Grade \| Grade	7.68	8.04
Commercial Portfolio Segment [Member] \| 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Risk Grade \| Grade	6.37
Commercial Portfolio Segment [Member] \| 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Risk Grade \| Grade	7.05	5.91
Commercial Portfolio Segment [Member] \| 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Risk Grade \| Grade	6.01	6.30
Commercial Portfolio Segment [Member] \| 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Risk Grade \| Grade	6.59	6.89
Commercial Portfolio Segment [Member] \| 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Risk Grade \| Grade	6.87	7.06
Commercial Portfolio Segment [Member] \| 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Risk Grade \| Grade		5.91
Commercial Portfolio Segment [Member] \| Prior Years
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Risk Grade \| Grade	5.55	5.80
Commercial and Industrial Total Energy Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 352,224	$ 475,023
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	100,862	9,539
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	5,312	20,991
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	8,659	9,480
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	3,078	3,110
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	2,913	5,638
Financing Receivable, Revolving	408,022	483,020
Loans, net of unearned discounts	$ 925,729	$ 1,077,792
Weighted Average Risk Grade \| Grade	5.67	6.06
Commercial and Industrial Total Energy Loans [Member] \| Revolving Credit Facility
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Risk Grade \| Grade	5.18	5.61
Commercial and Industrial Total Energy Loans [Member] \| Revolving Loans Converted to Term
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Revolving, Converted to Term Loan	$ 44,659	$ 70,991
Weighted Average Risk Grade \| Grade	5.69	6.46
Commercial and Industrial Total Energy Loans [Member] \| 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Risk Grade \| Grade	6.09
Commercial and Industrial Total Energy Loans [Member] \| 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Risk Grade \| Grade	5.65	6.21
Commercial and Industrial Total Energy Loans [Member] \| 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Risk Grade \| Grade	7.65	7.81
Commercial and Industrial Total Energy Loans [Member] \| 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Risk Grade \| Grade	9.64	9.34
Commercial and Industrial Total Energy Loans [Member] \| 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Risk Grade \| Grade	8.02	8.60
Commercial and Industrial Total Energy Loans [Member] \| 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Risk Grade \| Grade		7.12
Commercial and Industrial Total Energy Loans [Member] \| Prior Years
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Risk Grade \| Grade	6.59	7.63
Commercial Real Estate, Buildings, Land and Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 1,901,888	$ 1,761,554
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	1,528,173	1,257,055
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	1,009,197	1,008,366
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	745,031	632,020
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	410,327	612,767
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	882,021	825,249
Financing Receivable, Revolving	120,958	59,595
Loans, net of unearned discounts	$ 6,706,078	$ 6,272,339
Weighted Average Risk Grade \| Grade	7.09	7.22
Commercial Real Estate, Buildings, Land and Other [Member] \| Revolving Credit Facility
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Risk Grade \| Grade	7.38	7.06
Commercial Real Estate, Buildings, Land and Other [Member] \| Revolving Loans Converted to Term
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Revolving, Converted to Term Loan	$ 108,483	$ 115,733
Weighted Average Risk Grade \| Grade	6.43	7.02
Commercial Real Estate, Buildings, Land and Other [Member] \| 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Risk Grade \| Grade	7.01
Commercial Real Estate, Buildings, Land and Other [Member] \| 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Risk Grade \| Grade	7.26	7.19
Commercial Real Estate, Buildings, Land and Other [Member] \| 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Risk Grade \| Grade	7.14	7.18
Commercial Real Estate, Buildings, Land and Other [Member] \| 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Risk Grade \| Grade	7.01	7.35
Commercial Real Estate, Buildings, Land and Other [Member] \| 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Risk Grade \| Grade	7.33	7.39
Commercial Real Estate, Buildings, Land and Other [Member] \| 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Risk Grade \| Grade		7.34
Commercial Real Estate, Buildings, Land and Other [Member] \| Prior Years
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Risk Grade \| Grade	6.94	7.01
Construction Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 666,024	$ 693,192
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	491,563	268,080
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	130,888	178,226
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	2,236	2,339
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	486	484
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,726	1,930
Financing Receivable, Revolving	181,180	160,020
Loans, net of unearned discounts	$ 1,477,247	$ 1,304,271
Weighted Average Risk Grade \| Grade	7.12	7.06
Construction Loans [Member] \| Revolving Credit Facility
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Risk Grade \| Grade	7.23	6.79
Construction Loans [Member] \| Revolving Loans Converted to Term
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Revolving, Converted to Term Loan	$ 3,144	$ 0
Weighted Average Risk Grade \| Grade	5.03	0
Construction Loans [Member] \| 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Risk Grade \| Grade	7.29
Construction Loans [Member] \| 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Risk Grade \| Grade	7.03	7.17
Construction Loans [Member] \| 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Risk Grade \| Grade	6.43	6.56
Construction Loans [Member] \| 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Risk Grade \| Grade	7.04	7.60
Construction Loans [Member] \| 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Risk Grade \| Grade	6	7.51
Construction Loans [Member] \| 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Risk Grade \| Grade		8.92
Construction Loans [Member] \| Prior Years
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Risk Grade \| Grade	6.76	6.73
Commercial Real Estate Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 2,567,912	$ 2,454,746
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	2,019,736	1,525,135
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	1,140,085	1,186,592
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	747,267	634,359
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	410,813	613,251
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	883,747	827,179
Financing Receivable, Revolving	302,138	219,615
Loans, net of unearned discounts	$ 8,183,325	$ 7,576,610
Weighted Average Risk Grade \| Grade	7.10	7.19
Commercial Real Estate Portfolio Segment [Member] \| Revolving Credit Facility
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Risk Grade \| Grade	7.29	6.86
Commercial Real Estate Portfolio Segment [Member] \| Revolving Loans Converted to Term
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Revolving, Converted to Term Loan	$ 111,627	$ 115,733
Weighted Average Risk Grade \| Grade	6.39	7.02
Commercial Real Estate Portfolio Segment [Member] \| 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Risk Grade \| Grade	7.08
Commercial Real Estate Portfolio Segment [Member] \| 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Risk Grade \| Grade	7.20	7.18
Commercial Real Estate Portfolio Segment [Member] \| 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Risk Grade \| Grade	7.06	7.07
Commercial Real Estate Portfolio Segment [Member] \| 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Risk Grade \| Grade	7.01	7.39
Commercial Real Estate Portfolio Segment [Member] \| 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Risk Grade \| Grade	7.33	7.39
Commercial Real Estate Portfolio Segment [Member] \| 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Risk Grade \| Grade		7.34
Commercial Real Estate Portfolio Segment [Member] \| Prior Years
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Risk Grade \| Grade	6.94	7
Risk Grade One To Eight [Member] \| Commercial Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 1,667,274	$ 1,567,883
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	618,756	657,529
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	485,908	350,563
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	226,835	179,209
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	123,768	146,064
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	192,791	131,201
Financing Receivable, Revolving	2,068,891	1,987,061
Loans, net of unearned discounts	$ 5,435,917	$ 5,063,847
Weighted Average Risk Grade \| Grade	6.24	6.01
Risk Grade One To Eight [Member] \| Commercial Portfolio Segment [Member] \| Revolving Loans Converted to Term
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Revolving, Converted to Term Loan	$ 51,694	$ 44,337
Risk Grade One To Eight [Member] \| Commercial and Industrial Total Energy Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	338,050	445,489
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	99,089	8,075
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	4,917	9,259
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	3,138	6,441
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	2,020	3,110
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	2,850	4,368
Financing Receivable, Revolving	393,957	464,454
Loans, net of unearned discounts	$ 887,182	$ 1,008,370
Weighted Average Risk Grade \| Grade	5.44	5.78
Risk Grade One To Eight [Member] \| Commercial and Industrial Total Energy Loans [Member] \| Revolving Loans Converted to Term
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Revolving, Converted to Term Loan	$ 43,161	$ 67,174
Risk Grade One To Eight [Member] \| Commercial Real Estate, Buildings, Land and Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	1,811,069	1,707,550
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	1,484,811	1,096,274
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	956,567	874,130
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	708,942	533,362
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	360,154	492,492
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	800,944	713,268
Financing Receivable, Revolving	111,778	52,150
Loans, net of unearned discounts	$ 6,340,028	$ 5,574,922
Weighted Average Risk Grade \| Grade	6.94	6.91
Risk Grade One To Eight [Member] \| Commercial Real Estate, Buildings, Land and Other [Member] \| Revolving Loans Converted to Term
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Revolving, Converted to Term Loan	$ 105,763	$ 105,696
Risk Grade One To Eight [Member] \| Construction Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	640,948	657,471
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	489,391	262,176
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	128,788	178,226
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	2,236	2,339
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	486	38
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,726	1,930
Financing Receivable, Revolving	163,293	160,020
Loans, net of unearned discounts	$ 1,430,012	$ 1,262,200
Weighted Average Risk Grade \| Grade	7.04	6.99
Risk Grade One To Eight [Member] \| Construction Loans [Member] \| Revolving Loans Converted to Term
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Revolving, Converted to Term Loan	$ 3,144	$ 0
Risk Grade Nine [Member] \| Commercial Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	31,275	32,866
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	34,950	21,094
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	3,651	24,683
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	5,400	26,327
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	11,006	612
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,014	11,419
Financing Receivable, Revolving	54,856	65,131
Loans, net of unearned discounts	146,192	187,870
Risk Grade Nine [Member] \| Commercial Portfolio Segment [Member] \| Revolving Loans Converted to Term
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Revolving, Converted to Term Loan	4,040	5,738
Risk Grade Nine [Member] \| Commercial and Industrial Total Energy Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	1,561	19,274
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	1,611	611
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	166	1,775
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	562	187
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	748	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	0	724
Financing Receivable, Revolving	6,434	11,635
Loans, net of unearned discounts	11,112	36,622
Risk Grade Nine [Member] \| Commercial and Industrial Total Energy Loans [Member] \| Revolving Loans Converted to Term
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Revolving, Converted to Term Loan	30	2,416
Risk Grade Nine [Member] \| Commercial Real Estate, Buildings, Land and Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	52,288	16,302
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	13,139	145,340
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	36,264	52,427
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	22,086	43,806
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	17,699	27,188
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	45,590	27,767
Financing Receivable, Revolving	652	4,445
Loans, net of unearned discounts	189,928	321,533
Risk Grade Nine [Member] \| Commercial Real Estate, Buildings, Land and Other [Member] \| Revolving Loans Converted to Term
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Revolving, Converted to Term Loan	2,210	4,258
Risk Grade Nine [Member] \| Construction Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	12,865	35,721
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	2,100	4,956
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	2,100	0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	0	0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0	446
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	0	0
Financing Receivable, Revolving	17,887	0
Loans, net of unearned discounts	34,952	41,123
Risk Grade Nine [Member] \| Construction Loans [Member] \| Revolving Loans Converted to Term
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Revolving, Converted to Term Loan	0	0
Risk Grade Ten [Member] \| Commercial Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	2,294	27,961
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	724	6,273
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	845	4,047
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	4,713	4,357
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	1,341	1,021
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	114	98
Financing Receivable, Revolving	23,880	14,091
Loans, net of unearned discounts	37,596	59,137
Risk Grade Ten [Member] \| Commercial Portfolio Segment [Member] \| Revolving Loans Converted to Term
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Revolving, Converted to Term Loan	3,685	1,289
Risk Grade Ten [Member] \| Commercial and Industrial Total Energy Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0	0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	0	101
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	0	631
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	428	511
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	214	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	0	0
Financing Receivable, Revolving	0	0
Loans, net of unearned discounts	642	1,773
Risk Grade Ten [Member] \| Commercial and Industrial Total Energy Loans [Member] \| Revolving Loans Converted to Term
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Revolving, Converted to Term Loan	0	530
Risk Grade Ten [Member] \| Commercial Real Estate, Buildings, Land and Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	26,688	28,209
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	11,150	13,813
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	3,735	69,643
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	9,008	46,250
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	29,683	64,950
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	5,221	46,582
Financing Receivable, Revolving	5,535	0
Loans, net of unearned discounts	91,020	269,447
Risk Grade Ten [Member] \| Commercial Real Estate, Buildings, Land and Other [Member] \| Revolving Loans Converted to Term
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Revolving, Converted to Term Loan	0	0
Risk Grade Ten [Member] \| Construction Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	859	0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	72	0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	0	0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	0	0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	0	0
Financing Receivable, Revolving	0	0
Loans, net of unearned discounts	931	0
Risk Grade Ten [Member] \| Construction Loans [Member] \| Revolving Loans Converted to Term
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Revolving, Converted to Term Loan	0	0
Risk Grade Eleven [Member] \| Commercial Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	2,342	1,178
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	1,357	4,572
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	6,720	8,068
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	1,807	2,450
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	1,229	2,460
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,644	221
Financing Receivable, Revolving	19,582	4,714
Loans, net of unearned discounts	36,963	31,518
Risk Grade Eleven [Member] \| Commercial Portfolio Segment [Member] \| Revolving Loans Converted to Term
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Revolving, Converted to Term Loan	2,282	7,855
Risk Grade Eleven [Member] \| Commercial and Industrial Total Energy Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	7,956	10,260
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	162	752
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	157	3,968
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	3,145	1,016
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	86	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	63	546
Financing Receivable, Revolving	0	0
Loans, net of unearned discounts	11,569	16,594
Risk Grade Eleven [Member] \| Commercial and Industrial Total Energy Loans [Member] \| Revolving Loans Converted to Term
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Revolving, Converted to Term Loan	0	52
Risk Grade Eleven [Member] \| Commercial Real Estate, Buildings, Land and Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	10,199	3,455
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	19,073	1,321
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	12,631	8,720
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	4,778	7,788
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	2,525	26,107
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	28,841	34,970
Financing Receivable, Revolving	2,993	3,000
Loans, net of unearned discounts	81,550	91,140
Risk Grade Eleven [Member] \| Commercial Real Estate, Buildings, Land and Other [Member] \| Revolving Loans Converted to Term
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Revolving, Converted to Term Loan	510	5,779
Risk Grade Eleven [Member] \| Construction Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	11,352	0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	0	0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	0	0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	0	0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	0	0
Financing Receivable, Revolving	0	0
Loans, net of unearned discounts	11,352	0
Risk Grade Eleven [Member] \| Construction Loans [Member] \| Revolving Loans Converted to Term
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Revolving, Converted to Term Loan	0	0
Risk Grade Twelve [Member] \| Commercial Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0	456
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	1,052	2,495
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	866	3,828
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	2,972	1,756
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	1,177	347
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	191	353
Financing Receivable, Revolving	673	613
Loans, net of unearned discounts	12,521	12,535
Risk Grade Twelve [Member] \| Commercial Portfolio Segment [Member] \| Revolving Loans Converted to Term
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Revolving, Converted to Term Loan	5,590	2,687
Risk Grade Twelve [Member] \| Commercial and Industrial Total Energy Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	3,995	0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	0	0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	72	3,888
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	1,386	246
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	10	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	0	0
Financing Receivable, Revolving	4,571	4,000
Loans, net of unearned discounts	10,840	8,953
Risk Grade Twelve [Member] \| Commercial and Industrial Total Energy Loans [Member] \| Revolving Loans Converted to Term
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Revolving, Converted to Term Loan	806	819
Risk Grade Twelve [Member] \| Commercial Real Estate, Buildings, Land and Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	1,049	5,838
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	0	307
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	0	3,446
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	217	814
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	266	2,030
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,425	2,662
Financing Receivable, Revolving	0	0
Loans, net of unearned discounts	2,957	15,097
Risk Grade Twelve [Member] \| Commercial Real Estate, Buildings, Land and Other [Member] \| Revolving Loans Converted to Term
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Revolving, Converted to Term Loan	0	0
Risk Grade Twelve [Member] \| Construction Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0	0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	0	748
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	0	0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	0	0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	0	0
Financing Receivable, Revolving	0	0
Loans, net of unearned discounts	0	748
Risk Grade Twelve [Member] \| Construction Loans [Member] \| Revolving Loans Converted to Term
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Revolving, Converted to Term Loan	0	0
Risk Grade Thirteen [Member] \| Commercial Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0	180
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	200	1,361
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	223	1,219
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	270	64
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	20	418
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	0	0
Financing Receivable, Revolving	2,300	4,022
Loans, net of unearned discounts	5,609	10,047
Risk Grade Thirteen [Member] \| Commercial Portfolio Segment [Member] \| Revolving Loans Converted to Term
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Revolving, Converted to Term Loan	2,596	2,783
Risk Grade Thirteen [Member] \| Commercial and Industrial Total Energy Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	662	0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	0	0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	0	1,470
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	0	1,079
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	0	0
Financing Receivable, Revolving	3,060	2,931
Loans, net of unearned discounts	4,384	5,480
Risk Grade Thirteen [Member] \| Commercial and Industrial Total Energy Loans [Member] \| Revolving Loans Converted to Term
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Revolving, Converted to Term Loan	662	0
Risk Grade Thirteen [Member] \| Commercial Real Estate, Buildings, Land and Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	595	200
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	0	0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	0	0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	0	0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	0	0
Financing Receivable, Revolving	0	0
Loans, net of unearned discounts	595	200
Risk Grade Thirteen [Member] \| Commercial Real Estate, Buildings, Land and Other [Member] \| Revolving Loans Converted to Term
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Revolving, Converted to Term Loan	0	0
Risk Grade Thirteen [Member] \| Construction Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0	0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	0	200
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	0	0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	0	0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	0	0
Financing Receivable, Revolving	0	0
Loans, net of unearned discounts	0	200
Risk Grade Thirteen [Member] \| Construction Loans [Member] \| Revolving Loans Converted to Term
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Revolving, Converted to Term Loan	$ 0	$ 0

Loans (Age Analysis of Past D_2

Loans (Age Analysis of Past Due Consumer Loans, Segregated By Class and Year of Origination) (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned discounts	$ 17,154,969	$ 16,336,397
Financing Receivables, 30 to 89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	80,940
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	43,270
Financial Asset, Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	124,210
Financial Asset, Not Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	17,030,759
Total consumer real estate loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned discounts	1,843,539	1,410,790
Total consumer real estate loans [Member] \| Revolving Credit Facility
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned discounts	679,330	506,450
Total consumer real estate loans [Member] \| Revolving Loans Converted to Term
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned discounts	12,770	12,725
Total consumer real estate loans [Member] \| Financing Receivables, 30 to 89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	7,856	4,877
Total consumer real estate loans [Member] \| Financing Receivables, 30 to 89 Days Past Due [Member] \| Revolving Credit Facility
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	565	126
Total consumer real estate loans [Member] \| Financing Receivables, 30 to 89 Days Past Due [Member] \| Revolving Loans Converted to Term
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	1,202	1,732
Total consumer real estate loans [Member] \| Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	2,690	2,513
Total consumer real estate loans [Member] \| Financial Asset, Equal to or Greater than 90 Days Past Due [Member] \| Revolving Credit Facility
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	347	991
Total consumer real estate loans [Member] \| Financial Asset, Equal to or Greater than 90 Days Past Due [Member] \| Revolving Loans Converted to Term
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	914	185
Total consumer real estate loans [Member] \| Financial Asset, Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	10,546	7,390
Total consumer real estate loans [Member] \| Financial Asset, Past Due \| Revolving Credit Facility
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	912	1,117
Total consumer real estate loans [Member] \| Financial Asset, Past Due \| Revolving Loans Converted to Term
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	2,116	1,917
Total consumer real estate loans [Member] \| Financial Asset, Not Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	1,832,993	1,403,400
Total consumer real estate loans [Member] \| Financial Asset, Not Past Due \| Revolving Credit Facility
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	678,418	505,333
Total consumer real estate loans [Member] \| Financial Asset, Not Past Due \| Revolving Loans Converted to Term
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	10,654	10,808
Consumer Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned discounts	492,726	477,369
Consumer Loan [Member] \| Revolving Credit Facility
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned discounts	372,456	372,225
Consumer Loan [Member] \| Revolving Loans Converted to Term
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned discounts	23,732	26,318
Consumer Loan [Member] \| Financing Receivables, 30 to 89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	5,155	4,185
Consumer Loan [Member] \| Financing Receivables, 30 to 89 Days Past Due [Member] \| Revolving Credit Facility
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	314	325
Consumer Loan [Member] \| Financing Receivables, 30 to 89 Days Past Due [Member] \| Revolving Loans Converted to Term
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	1,443	1,943
Consumer Loan [Member] \| Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	311	1,076
Consumer Loan [Member] \| Financial Asset, Equal to or Greater than 90 Days Past Due [Member] \| Revolving Credit Facility
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	25	34
Consumer Loan [Member] \| Financial Asset, Equal to or Greater than 90 Days Past Due [Member] \| Revolving Loans Converted to Term
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	194	449
Consumer Loan [Member] \| Financial Asset, Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	5,466	5,261
Consumer Loan [Member] \| Financial Asset, Past Due \| Revolving Credit Facility
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	339	359
Consumer Loan [Member] \| Financial Asset, Past Due \| Revolving Loans Converted to Term
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	1,637	2,392
Consumer Loan [Member] \| Financial Asset, Not Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	487,260	472,108
Consumer Loan [Member] \| Financial Asset, Not Past Due \| Revolving Credit Facility
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	372,117	371,866
Consumer Loan [Member] \| Financial Asset, Not Past Due \| Revolving Loans Converted to Term
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	22,095	23,926
2022 \| Total consumer real estate loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned discounts	404,475
2022 \| Total consumer real estate loans [Member] \| Financing Receivables, 30 to 89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	793
2022 \| Total consumer real estate loans [Member] \| Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	95
2022 \| Total consumer real estate loans [Member] \| Financial Asset, Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	888
2022 \| Total consumer real estate loans [Member] \| Financial Asset, Not Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	403,587
2022 \| Consumer Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned discounts	62,636
2022 \| Consumer Loan [Member] \| Financing Receivables, 30 to 89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	2,673
2022 \| Consumer Loan [Member] \| Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	77
2022 \| Consumer Loan [Member] \| Financial Asset, Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	2,750
2022 \| Consumer Loan [Member] \| Financial Asset, Not Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	59,886
2021 \| Total consumer real estate loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned discounts	314,605	319,322
2021 \| Total consumer real estate loans [Member] \| Financing Receivables, 30 to 89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	1,125	280
2021 \| Total consumer real estate loans [Member] \| Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	258	0
2021 \| Total consumer real estate loans [Member] \| Financial Asset, Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	1,383	280
2021 \| Total consumer real estate loans [Member] \| Financial Asset, Not Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	313,222	319,042
2021 \| Consumer Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned discounts	21,400	48,856
2021 \| Consumer Loan [Member] \| Financing Receivables, 30 to 89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	511	1,600
2021 \| Consumer Loan [Member] \| Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	2	548
2021 \| Consumer Loan [Member] \| Financial Asset, Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	513	2,148
2021 \| Consumer Loan [Member] \| Financial Asset, Not Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	20,887	46,708
2020 \| Total consumer real estate loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned discounts	195,573	251,364
2020 \| Total consumer real estate loans [Member] \| Financing Receivables, 30 to 89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	645	204
2020 \| Total consumer real estate loans [Member] \| Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	28	0
2020 \| Total consumer real estate loans [Member] \| Financial Asset, Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	673	204
2020 \| Total consumer real estate loans [Member] \| Financial Asset, Not Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	194,900	251,160
2020 \| Consumer Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned discounts	6,603	17,934
2020 \| Consumer Loan [Member] \| Financing Receivables, 30 to 89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	128	91
2020 \| Consumer Loan [Member] \| Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	0	0
2020 \| Consumer Loan [Member] \| Financial Asset, Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	128	91
2020 \| Consumer Loan [Member] \| Financial Asset, Not Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	6,475	17,843
2019 \| Total consumer real estate loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned discounts	71,659	96,306
2019 \| Total consumer real estate loans [Member] \| Financing Receivables, 30 to 89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	936	406
2019 \| Total consumer real estate loans [Member] \| Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	0	0
2019 \| Total consumer real estate loans [Member] \| Financial Asset, Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	936	406
2019 \| Total consumer real estate loans [Member] \| Financial Asset, Not Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	70,723	95,900
2019 \| Consumer Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned discounts	2,961	6,380
2019 \| Consumer Loan [Member] \| Financing Receivables, 30 to 89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	51	120
2019 \| Consumer Loan [Member] \| Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	13	45
2019 \| Consumer Loan [Member] \| Financial Asset, Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	64	165
2019 \| Consumer Loan [Member] \| Financial Asset, Not Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	2,897	6,215
2018 \| Total consumer real estate loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned discounts	39,536	56,536
2018 \| Total consumer real estate loans [Member] \| Financing Receivables, 30 to 89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	503	489
2018 \| Total consumer real estate loans [Member] \| Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	129	154
2018 \| Total consumer real estate loans [Member] \| Financial Asset, Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	632	643
2018 \| Total consumer real estate loans [Member] \| Financial Asset, Not Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	38,904	55,893
2018 \| Consumer Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned discounts	1,275	2,722
2018 \| Consumer Loan [Member] \| Financing Receivables, 30 to 89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	4	38
2018 \| Consumer Loan [Member] \| Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	0	0
2018 \| Consumer Loan [Member] \| Financial Asset, Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	4	38
2018 \| Consumer Loan [Member] \| Financial Asset, Not Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	1,271	2,684
2017 \| Total consumer real estate loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned discounts		49,492
2017 \| Total consumer real estate loans [Member] \| Financing Receivables, 30 to 89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss		296
2017 \| Total consumer real estate loans [Member] \| Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss		355
2017 \| Total consumer real estate loans [Member] \| Financial Asset, Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss		651
2017 \| Total consumer real estate loans [Member] \| Financial Asset, Not Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss		48,841
2017 \| Consumer Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned discounts		1,759
2017 \| Consumer Loan [Member] \| Financing Receivables, 30 to 89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss		51
2017 \| Consumer Loan [Member] \| Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss		0
2017 \| Consumer Loan [Member] \| Financial Asset, Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss		51
2017 \| Consumer Loan [Member] \| Financial Asset, Not Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss		1,708
Prior Years \| Total consumer real estate loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned discounts	125,591	118,595
Prior Years \| Total consumer real estate loans [Member] \| Financing Receivables, 30 to 89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	2,087	1,344
Prior Years \| Total consumer real estate loans [Member] \| Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	919	828
Prior Years \| Total consumer real estate loans [Member] \| Financial Asset, Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	3,006	2,172
Prior Years \| Total consumer real estate loans [Member] \| Financial Asset, Not Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	122,585	116,423
Prior Years \| Consumer Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned discounts	1,663	1,175
Prior Years \| Consumer Loan [Member] \| Financing Receivables, 30 to 89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	31	17
Prior Years \| Consumer Loan [Member] \| Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	0	0
Prior Years \| Consumer Loan [Member] \| Financial Asset, Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	31	17
Prior Years \| Consumer Loan [Member] \| Financial Asset, Not Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 1,632	$ 1,158

Loans (Revolving Loans Converte

Loans (Revolving Loans Converted to Term) (Details) - Revolving Loans Converted to Term - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Remaining Revolving Loans Converted to Term During Period	$ 67,441	$ 172,955
Commercial Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Remaining Revolving Loans Converted to Term During Period	34,247	40,099
Commercial and Industrial Total Energy Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Remaining Revolving Loans Converted to Term During Period	3,295	54,996
Commercial Real Estate, Buildings, Land and Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Remaining Revolving Loans Converted to Term During Period	12,174	68,337
Construction Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Remaining Revolving Loans Converted to Term During Period	3,144	0
Total consumer real estate loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Remaining Revolving Loans Converted to Term During Period	5,381	1,156
Consumer Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Remaining Revolving Loans Converted to Term During Period	$ 9,200	$ 8,367

Loans (Allowance for Credit Los

Loans (Allowance for Credit Loss By Loan Class Calculated in Accordance With CECL Methodology) (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	$ 227,621	$ 248,666
Commercial Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	104,237	72,091	$ 73,843	$ 51,593
Commercial and Industrial Total Energy Loans [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	18,062	17,217	39,553	37,382
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	90,301	144,936	134,892	31,037
Total consumer real estate loans [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	8,004	6,585	7,926	4,113
Consumer Loan [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	7,017	7,837	6,963	8,042
Loans Receivable [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	227,621	248,666	$ 263,177	$ 132,167
Modeled Expected Credit Losses [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	110,292	82,866
Modeled Expected Credit Losses [Member] \| Commercial Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	61,918	46,946
Modeled Expected Credit Losses [Member] \| Commercial and Industrial Total Energy Loans [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	8,531	6,363
Modeled Expected Credit Losses [Member] \| Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	27,013	16,676
Modeled Expected Credit Losses [Member] \| Total consumer real estate loans [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	7,847	6,484
Modeled Expected Credit Losses [Member] \| Consumer Loan [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	4,983	6,397
Q-factor adjustments [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	105,148	149,348
Q-factor adjustments [Member] \| Commercial Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	36,237	14,609
Q-factor adjustments [Member] \| Commercial and Industrial Total Energy Loans [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	5,148	5,374
Q-factor adjustments [Member] \| Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	61,572	127,860
Q-factor adjustments [Member] \| Total consumer real estate loans [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	157	65
Q-factor adjustments [Member] \| Consumer Loan [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	2,034	1,440
Specific Valuation Allowances [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	12,181	16,452
Specific Valuation Allowances [Member] \| Commercial Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	6,082	10,536
Specific Valuation Allowances [Member] \| Commercial and Industrial Total Energy Loans [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	4,383	5,480
Specific Valuation Allowances [Member] \| Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	1,716	400
Specific Valuation Allowances [Member] \| Total consumer real estate loans [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	0	36
Specific Valuation Allowances [Member] \| Consumer Loan [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	$ 0	$ 0

Loans (Activity in Allowance fo

Loans (Activity in Allowance for Loan Losses by Portfolio Segment) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Jan. 01, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Allowance for Credit Loss	$ 227,621	$ 248,666
Commercial Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Allowance for Credit Loss	104,237	72,091	$ 73,843		$ 51,593
Financing Receivable, Credit Loss, Expense (Reversal)	34,479	(2,160)	15,156
Financing Receivable, Allowance for Credit Loss, Writeoff	(6,575)	(5,513)	(18,908)
Financing Receivable, Allowance for Credit Loss, Recovery	4,242	5,921	4,739
Allowance for Loan and Lease Losses Write-offs, Net	(2,333)	408	(14,169)
Commercial Portfolio Segment [Member] \| Accounting Standards Update 2016-13 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Allowance for Credit Loss				$ 21,263
Commercial And Industrial Energy Financing Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Allowance for Credit Loss	18,062	17,217	39,553		37,382
Financing Receivable, Credit Loss, Expense (Reversal)	(313)	(19,207)	85,889
Financing Receivable, Allowance for Credit Loss, Writeoff	(371)	(5,331)	(76,107)
Financing Receivable, Allowance for Credit Loss, Recovery	1,529	2,202	2,842
Allowance for Loan and Lease Losses Write-offs, Net	1,158	(3,129)	(73,265)
Commercial And Industrial Energy Financing Receivable [Member] \| Accounting Standards Update 2016-13 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Allowance for Credit Loss				(10,453)
Commercial Real Estate Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Allowance for Credit Loss	90,301	144,936	134,892		31,037
Financing Receivable, Credit Loss, Expense (Reversal)	(54,775)	8,101	124,427
Financing Receivable, Allowance for Credit Loss, Writeoff	(702)	(399)	(7,499)
Financing Receivable, Allowance for Credit Loss, Recovery	842	2,342	446
Allowance for Loan and Lease Losses Write-offs, Net	140	1,943	(7,053)
Commercial Real Estate Portfolio Segment [Member] \| Accounting Standards Update 2016-13 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Allowance for Credit Loss				(13,519)
Total consumer real estate loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Allowance for Credit Loss	8,004	6,585	7,926		4,113
Financing Receivable, Credit Loss, Expense (Reversal)	1,813	(3,061)	1,906
Financing Receivable, Allowance for Credit Loss, Writeoff	(912)	(829)	(2,186)
Financing Receivable, Allowance for Credit Loss, Recovery	518	2,549	1,701
Allowance for Loan and Lease Losses Write-offs, Net	(394)	1,720	(485)
Total consumer real estate loans [Member] \| Accounting Standards Update 2016-13 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Allowance for Credit Loss				2,392
Consumer Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Allowance for Credit Loss	7,017	7,837	6,963		8,042
Financing Receivable, Credit Loss, Expense (Reversal)	13,517	10,230	9,632
Financing Receivable, Allowance for Credit Loss, Writeoff	(24,388)	(18,614)	(17,830)
Financing Receivable, Allowance for Credit Loss, Recovery	10,051	9,258	9,367
Allowance for Loan and Lease Losses Write-offs, Net	(14,337)	(9,356)	(8,463)
Consumer Loan [Member] \| Accounting Standards Update 2016-13 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Allowance for Credit Loss				(2,248)
Loans Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Allowance for Credit Loss	227,621	248,666	263,177		$ 132,167
Financing Receivable, Credit Loss, Expense (Reversal)	(5,279)	(6,097)	237,010
Financing Receivable, Allowance for Credit Loss, Writeoff	(32,948)	(30,686)	(122,530)
Financing Receivable, Allowance for Credit Loss, Recovery	17,182	22,272	19,095
Allowance for Loan and Lease Losses Write-offs, Net	$ (15,766)	$ (8,414)	$ (103,435)
Loans Receivable [Member] \| Accounting Standards Update 2016-13 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Allowance for Credit Loss				$ (2,565)

Loans (Investment in Loans Rela

Loans (Investment in Loans Related to Allowance for Loan Loss by Portfolio Segment Disaggregated Based on Impairment Methodology) (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	$ 17,154,969	$ 16,336,397
Commercial Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	5,674,798	5,364,954
Commercial and Industrial Total Energy Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	925,729	1,077,792
Paycheck Protection Program [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	34,852	428,882
Commercial Real Estate, Buildings, Land and Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	6,706,078	6,272,339
Construction Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	1,477,247	1,304,271
Total consumer real estate loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	1,843,539	1,410,790
Consumer Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	492,726	477,369
Specific Valuation Allowances [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Portion of allowance for loan losses	12,181	16,452
Specific Valuation Allowances [Member] \| Commercial Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Portion of allowance for loan losses	6,082	10,536
Specific Valuation Allowances [Member] \| Commercial and Industrial Total Energy Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Portion of allowance for loan losses	4,383	5,480
Specific Valuation Allowances [Member] \| Paycheck Protection Program [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Portion of allowance for loan losses	0	0
Specific Valuation Allowances [Member] \| Commercial Real Estate, Buildings, Land and Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Portion of allowance for loan losses	1,716	200
Specific Valuation Allowances [Member] \| Construction Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Portion of allowance for loan losses	0	200
Specific Valuation Allowances [Member] \| Total consumer real estate loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Portion of allowance for loan losses	0	36
Specific Valuation Allowances [Member] \| Consumer Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Portion of allowance for loan losses	0	0
Loans Individually Evaluated for Impairment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	52,576	66,837
Loans Individually Evaluated for Impairment [Member] \| Commercial Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	18,980	24,523
Loans Individually Evaluated for Impairment [Member] \| Commercial and Industrial Total Energy Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	15,058	16,393
Loans Individually Evaluated for Impairment [Member] \| Paycheck Protection Program [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	0	0
Loans Individually Evaluated for Impairment [Member] \| Commercial Real Estate, Buildings, Land and Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	17,711	24,670
Loans Individually Evaluated for Impairment [Member] \| Construction Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	0	948
Loans Individually Evaluated for Impairment [Member] \| Total consumer real estate loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	827	303
Loans Individually Evaluated for Impairment [Member] \| Consumer Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	$ 0	$ 0

Premises and Equipment (Narrati

Premises and Equipment (Narrative) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Depreciation	$ 57,400	$ 55,100	$ 49,900
Operating Lease, Rent Expense	47,700	45,600	46,000
Operating Lease, Right-of-Use Asset	288,816	281,438
Operating lease, payments	32,900	32,100
Premises and Equipment
Property, Plant and Equipment [Line Items]
Operating Lease, Right-of-Use Asset	288,800	281,400
Other Liabilities [Member]
Property, Plant and Equipment [Line Items]
Operating lease, liability	321,945	313,400
Partnership Interest [Member]
Property, Plant and Equipment [Line Items]
Operating Lease, Rent Expense	$ 327	$ 322	$ 9,800

Premises and Equipment (Premise

Premises and Equipment (Premises and Equipment) (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Property, Plant and Equipment [Abstract]
Land	$ 170,938	$ 152,219
Buildings	521,280	495,903
Technology, furniture and equipment	236,440	256,323
Leasehold improvements	209,398	192,207
Construction and projects in progress	39,506	14,513
Operating lease, right-of-use asset	288,816	281,438
Premises and equipment, Gross	1,466,378	1,392,603
Less accumulated depreciation and amortization	(363,683)	(342,272)
Total premises and equipment, net	$ 1,102,695	$ 1,050,331

Premises and Equipment (Lease C

Premises and Equipment (Lease Commitments, Components of Lease Expense) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Property, Plant and Equipment [Line Items]
Amortization of lease right-of-use assets	$ 33,285	$ 32,811
Short-term lease expense	2,208	1,595
Non-lease components (including taxes, insurance, common maintenance, etc.)	12,172	11,203
Total operating lease expense, excluding rent	$ 47,665	$ 45,609

Premises and Equipment Future M

Premises and Equipment Future Minimum Lease Payments Due Under non-Cancelable Operating Leases (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Property, Plant and Equipment [Line Items]
2023	$ 33,685
2024	33,651
2025	33,990
2026	33,600
2027	32,023
Thereafter	232,905
Total undiscounted operating lease liability	399,854
Imputed interest	$ 77,909
Weighted-average lease term in years	13 years 7 months 13 days
Weighted-average discount rate	3.13%
Other Liabilities [Member]
Property, Plant and Equipment [Line Items]
Operating lease, liability	$ 321,945	$ 313,400

Goodwill and Other Intangible_3

Goodwill and Other Intangible Assets (Narrative) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Amortization expense related to intangible assets	$ 480	$ 697	$ 918
Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Other intangible assets estimated lives, years	5 years
Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Other intangible assets estimated lives, years	10 years

Goodwill and Other Intangible_4

Goodwill and Other Intangible Assets (Schedule of Goodwill) (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	$ 654,952	$ 654,952

Goodwill and Other Intangible_5

Goodwill and Other Intangible Assets (Schedule of Other Intangible Assets) (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Finite-Lived Intangible Assets [Line Items]
Gross Intangible Assets	$ 10,821	$ 11,685
Accumulated Amortization	(10,435)	(10,819)
Net Intangible Assets	386	866
Core Deposits [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Intangible Assets	9,300	9,300
Accumulated Amortization	(8,990)	(8,582)
Net Intangible Assets	310	718
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Intangible Assets	1,521	2,385
Accumulated Amortization	(1,445)	(2,237)
Net Intangible Assets	$ 76	$ 148

Goodwill and Other Intangible_6

Goodwill and Other Intangible Assets (Estimated Aggregate Future Amortization Expense for Intangible Assets) (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
2023	$ 283
2024	87
2025	11
2026	5
Finite-Lived Intangible Assets, Net, Total	$ 386	$ 866

Deposits (Schedule of Deposits)

Deposits (Schedule of Deposits) (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Deposit Liability [Line Items]
Non-interest-bearing demand deposits	$ 17,598,234	$ 18,423,018
Savings and interest checking	12,333,675	11,930,959
Money market accounts	12,227,247	11,228,815
Time accounts	1,795,040	1,112,904
Total Interest-bearing deposits	26,355,962	24,272,678
Total deposits	$ 43,954,196	$ 42,695,696

Deposits (Additional Informatio

Deposits (Additional Information About Corporation's Deposits) (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Deposit Liability [Line Items]
Deposits from foreign sources (primarily Mexico)	$ 1,048,943	$ 993,479
Non-interest-bearing public funds deposits	17,598,234	18,423,018
Interest-bearing public funds deposits	26,355,962	24,272,678
Total deposits not covered by deposit insurance	23,839,797	24,125,359
Time deposits not covered by deposit insurance	430,128	238,608
Deposits from certain directors, executive officers and their affiliates	153,083	276,556
Public Funds [Member]
Deposit Liability [Line Items]
Non-interest-bearing public funds deposits	788,040	1,235,026
Interest-bearing public funds deposits	$ 758,761	$ 810,863

Deposits (Scheduled Maturities

Deposits (Scheduled Maturities of Time Deposits) (Detail) $ in Thousands	Dec. 31, 2022 USD ($)
Deposits [Abstract]
2023	$ 1,381,519
2024	413,521
Time deposits, Total	$ 1,795,040

Deposits (Scheduled Maturitie_2

Deposits (Scheduled Maturities of Time Deposits Not Covered By Deposit Insurance) (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Deposits [Abstract]
Due within 3 months or less	$ 87,254
Due after 3 months and within 6 months	87,035
Due after 6 months and within 12 months	131,503
Due after 12 months	124,336
Time deposits liability, above US Insurance Limit Total	$ 430,128	$ 238,608

Borrowed Funds (Narrative) (Det

Borrowed Funds (Narrative) (Detail) $ in Thousands		3 Months Ended	12 Months Ended
Borrowed Funds (Narrative) (Detail) $ in Thousands	Mar. 17, 2017 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2022 USD ($) quarter	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2004 USD ($)
Borrowed Funds [Line Items]
Federal funds purchased		$ 25,925	$ 51,650	$ 25,925
Repurchase agreements		2,740,799	4,660,641	2,740,799
Subordinated notes		99,178	99,335	99,178
Junior subordinated deferrable interest debentures		123,011	123,069	123,011
Principal payments on long-term borrowings			$ 0	13,403	$ 0
Proceeds from issuance of Common Equity Securities					$ 145,452
Maximum number of quarterly periods by which the corporation has the right to defer interest payments on junior subordinated deferrable interest debentures \| quarter			20
Cullen Frost Capital Trust II [Member]
Borrowed Funds [Line Items]
Maturity date						Mar. 01, 2034
Proceeds from Issuance of Trust Preferred Securities						$ 120,000
Floating rate 3 month Libor plus margin						1.55%
Proceeds from issuance of Common Equity Securities						$ 3,700
Federal Funds Purchased [Member] \| Minimum [Member]
Borrowed Funds [Line Items]
Short term debt maturity period			1 day
Federal Funds Purchased [Member] \| Maximum [Member]
Borrowed Funds [Line Items]
Short term debt maturity period			90 days
Securities Loaned or Sold under Agreements to Repurchase [Member] \| Minimum [Member]
Borrowed Funds [Line Items]
Short term debt maturity period			30 days
Securities Loaned or Sold under Agreements to Repurchase [Member] \| Maximum [Member]
Borrowed Funds [Line Items]
Short term debt maturity period			90 days
Subordinated Debt [Member]
Borrowed Funds [Line Items]
Subordinated notes	$ 100,000
Subordinated notes interest rate	4.50%
Maturity date	Mar. 17, 2027
Unamortized debt issuance cost related to note		822	$ 665	822
Junior Subordinated Deferrable Interest Debenture [Member] \| Cullen Frost Capital Trust II [Member]
Borrowed Funds [Line Items]
Unamortized debt issuance cost related to note		701	643	701
Junior subordinated deferrable interest debentures		123,700	$ 123,700	$ 123,700		$ 123,700
Floating rate 3 month Libor plus margin			6.31%	1.72%
Junior Subordinated Deferrable Interest Debenture [Member] \| WNB Capital Trust I [Member]
Borrowed Funds [Line Items]
Principal payments on long-term borrowings		$ 13,400

Off-Balance Sheet Arrangements

Off-Balance Sheet Arrangements Commitments Guarantees and Contingencies (Narrative) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Commitments And Guarantees [Line Items]
Credit card guarantees	$ 8,000	$ 8,600
Fully collateralized credit card guarantees	897	962
Frost Wealth Advisors [Member]
Commitments And Guarantees [Line Items]
Fair value of off-balance sheet managed and custody assets	$ 43,600,000	$ 43,300,000	$ 38,600,000

Off-Balance-Sheet Arrangement_3

Off-Balance-Sheet Arrangements, Commitments, Guarantees and Contingencies (Financial Instruments With Off-Balance-Sheet Risk) (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Standby Letters of Credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial instruments with off- balance-sheet risk	$ 383,851	$ 238,690
Deferred Standby Letter of Credit Fees [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial instruments with off- balance-sheet risk	2,236	2,072
Commitments to Extend Credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial instruments with off- balance-sheet risk	$ 12,137,957	$ 10,420,142

Off-Balance-Sheet Arrangement_4

Off-Balance-Sheet Arrangements, Commitments, Guarantees and Contingencies - Credit Losses on Off-Balance-Sheet Commitments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Off-Balance Sheet, Credit Loss, Liability, Beginning Balance	$ 50,314	$ 44,152	$ 500
Impact of New Accounting Pronouncement	0	0	39,377
Off-Balance Sheet, Credit Loss, Liability, Credit Loss Expense (Reversal)	8,279	6,162	4,275
Off-Balance Sheet, Credit Loss, Liability, Ending Balance	$ 58,593	$ 50,314	$ 44,152

Capital and Regulatory Matter_2

Capital and Regulatory Matters (Narrative) (Detail)						3 Months Ended	12 Months Ended
Capital and Regulatory Matters (Narrative) (Detail)	Jan. 25, 2023 USD ($)	Nov. 19, 2020 USD ($) $ / shares shares	Mar. 16, 2020 USD ($) $ / shares	Mar. 17, 2017 USD ($)	Feb. 15, 2013 USD ($) $ / shares shares	Mar. 31, 2020 USD ($) shares	Dec. 31, 2022 USD ($) quarter $ / shares Rate shares	Dec. 31, 2021 USD ($) $ / shares Rate shares	Dec. 31, 2020 USD ($) shares	Jan. 01, 2020 USD ($)	Dec. 31, 2019 USD ($)	Jan. 01, 2019 Rate
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Credit loss optional transitional period under CECL							5 years
Subordinated notes							$ 99,335,000	$ 99,178,000
Cumulative effect of accounting change											$ (29,252,000)
Credit loss transitional period in years under CECL							3 years
CECL Transition Amount							$ 46,200,000	$ 61,600,000
Stock Redeemed or Called During Period, Value									$ 150,000,000
Treasury stock, shares, acquired \| shares							31,351	31,317	206,951
Treasury Stock, Value, Acquired, Cost Method							$ (4,391,000)	$ (3,864,000)	$ (15,785,000)
Aggregate dividends available for payment without prior regulatory approval							$ 813,600,000
Maximum number of quarterly periods by which the corporation has the right to defer interest payments on junior subordinated deferrable interest debentures \| quarter							20
Subsequent Event
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Share repurchase authorized amount	$ 100,000,000
Stock repurchase program, period in force	1 year
Retained Earnings [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Cumulative effect of accounting change										$ (29,300,000)	$ (29,252,000)
Stock Redeemed or Called During Period, Value									$ 5,514,000
Series A Preferred Stock [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Non-cumulative perpetual preferred stock, dividend rate percentage					5.375%
Preferred Stock, Shares Issued \| shares					6,000,000
Preferred Stock, Aggregate Liquidation Preference, Value					$ 150,000,000
Preferred Stock, Par or Stated Value Per Share \| $ / shares					$ 0.01
Liquidation preference per share \| $ / shares			$ 25		$ 25
Payments of Stock Issuance Costs					$ 5,500,000
Proceeds from issuance of preferred stock					$ 144,500,000
Stock Redeemed or Called During Period, Value			$ 150,000,000
Series B Preferred Stock [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Non-cumulative perpetual preferred stock, dividend rate percentage		4.45%
Preferred Stock, Shares Issued \| shares		150,000					150,000	150,000
Preferred Stock, Aggregate Liquidation Preference, Value		$ 150,000,000					$ 1,000	$ 1,000
Preferred Stock, Par or Stated Value Per Share \| $ / shares		$ 0.01					$ 0.01	$ 0.01
Liquidation preference per share \| $ / shares		$ 1,000
Number of Preferred Stock equivalent depositary shares \| shares		40
Payments of Stock Issuance Costs		$ 4,500,000
Proceeds from issuance of preferred stock		$ 145,500,000
Series B Preferred Stock Equivalent Depositary Shares Member [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Liquidation preference per share \| $ / shares		$ 25
Subordinated Debt [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Subordinated notes				$ 100,000,000
Subordinated notes interest rate				4.50%
Per year percentage of decreases in permissible portion of Subordinate Note included in Total Capital							20%
Final years of the term of the notes							5 years
Cullen/Frost [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Additional Tier 1 Capital beyond Common Equity Tier 1							$ 145,500,000	$ 145,500,000
Non-cumulative perpetual preferred stock, dividend rate percentage		4.45%
Common Equity Tier One Risk Based Capital To Risk Weighted Assets Minimum Capital Required Basel III Phase In Schedule, Ratio												4.50%
Capital Conservation Buffer												2.50%
Effective common equity tier one capital to risk weighted assets, ratio upon full implementation							7%	7%				7%
Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets \| Rate												6%
Effective tier one capital ratio, upon full implementation							8.50%	8.50%				8.50%
Minimum ratio of Total capital to risk weighted assets \| Rate							14.84%	15.45%				8%
Tier one risk based capital to risk weighted assets, ratio upon full implementation							10.50%	10.50%				10.50%
Minimum leverage ratio							4%	4%				4%
Cullen/Frost [Member] \| Trust Preferred Securities Tier Two Capital Allowable Portion [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Trust preferred securities							$ 120,000,000	$ 120,000,000
Cullen/Frost [Member] \| Subordinated Debt [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Permissible Portion Of Subordinated Note Included In Capital							80,000,000	100,000,000
Frost Bank [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Additional Tier 1 Capital beyond Common Equity Tier 1							$ 0	$ 0
Common Equity Tier One Risk Based Capital To Risk Weighted Assets Minimum Capital Required Basel III Phase In Schedule, Ratio												4.50%
Capital Conservation Buffer												2.50%
Effective common equity tier one capital to risk weighted assets, ratio upon full implementation							7%	7%				7%
Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets \| Rate												6%
Effective tier one capital ratio, upon full implementation							8.50%	8.50%				8.50%
Minimum ratio of Total capital to risk weighted assets \| Rate							13.80%	13.61%				8%
Tier one risk based capital to risk weighted assets, ratio upon full implementation							10.50%	10.50%				10.50%
Minimum leverage ratio							4%	4%				4%
stock repurchase 2022 plan \| Treasury Stock [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Treasury stock, shares, acquired \| shares							0
stock repurchase 2021 plan \| Treasury Stock [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Treasury stock, shares, acquired \| shares								0
Prior stock repurchase plans [Member] \| Treasury Stock [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Treasury stock, shares, acquired \| shares						177,834
Treasury Stock, Value, Acquired, Cost Method						$ (13,700,000)

Regulatory Matters (Actual and

Regulatory Matters (Actual and Required Capital Ratios) (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Jan. 01, 2019
Cullen/Frost [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier One to Risk-Weighted Assets, Actual, Capital Amount	$ 3,751,200	$ 3,371,043
Common Equity Tier One Risk-Based Capital Ratio, Actual	12.85%	13.13%
Common Equity Tier One Capital Required For Capital Adequacy Minimum Capital Required Plus Capital Conservation Buffer, Capital Amount	$ 2,042,876	$ 1,796,549
Common Equity Tier One Risk Based Capital To Risk Weighted Assets Minimum Capital Required Plus Capital Conservation Buffer, Ratio	7%	7%	7%
Tier 1 Capital to Risk-Weighted Assets, Actual, Capital Amount	$ 3,896,652	$ 3,516,495
Tier 1 Capital to Risk-Weighted Assets, Actual, Ratio	13.35%	13.70%
Tier One Risk Based Capital Required For Capital Adequacy Minimum Capital Required Plus Capital Conservation Buffer, Capital Amount	$ 2,480,635	$ 2,181,523
Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets Minimum Capital Required Plus Capital Conservation Buffer, Ratio	8.50%	8.50%	8.50%
Tier 1 Capital to Risk-Weighted Assets, Required to be Considered Well Capitalized, Capital Amount	$ 1,751,036	$ 1,539,899
Tier 1 Capital to Risk-Weighted Assets, Required to be Considered Well Capitalized, Ratio	6%	6%
Total Capital to Risk-Weighted Assets, Actual, Capital Amount	$ 4,330,982	$ 3,966,244
Total Capital to Risk-Weighted Assets, Actual, Ratio	14.84%	15.45%	8%
Capital Required for Capital Adequacy Minimum Capital Required Plus Capital Conservation Buffer, Capital Amount	$ 3,064,313	$ 2,694,823
Capital Required for Capital Adequacy to Risk Weighted Assets Minimum Capital Required Plus Capital Conservation Buffer, Ratio	10.50%	10.50%	10.50%
Total Capital to Risk-Weighted Assets, Required to be Considered Well Capitalized, Capital Amount	$ 2,918,394	$ 2,566,498
Total Capital to Risk-Weighted Assets, Required to be Considered Well Capitalized, Ratio	10%	10%
Leverage Ratio, Actual, Capital Amount	$ 3,896,652	$ 3,516,495
Leverage Ratio, Actual, Ratio	7.29%	7.34%
Tier One Leverage Capital Required for Capital Adequacy Minimum Capital Required Plus Capital Conservation Buffer, Capital Amount	$ 2,136,680	$ 1,917,533
Tier One Leverage Capital Required for Capital Adequacy to Average Assets Minimum Capital Required Plus Capital Conservation Buffer, Ratio	4%	4%	4%
Frost Bank [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier One to Risk-Weighted Assets, Actual, Capital Amount	$ 3,789,056	$ 3,261,532
Common Equity Tier One Risk-Based Capital Ratio, Actual	13%	12.72%
Common Equity Tier One Capital Required For Capital Adequacy Minimum Capital Required Plus Capital Conservation Buffer, Capital Amount	$ 2,040,388	$ 1,795,221
Common Equity Tier One Risk Based Capital To Risk Weighted Assets Minimum Capital Required Plus Capital Conservation Buffer, Ratio	7%	7%	7%
Common Equity Tier One Capital Required To Be Well Capitalized, Capital Amount	$ 1,894,646	$ 1,666,991
Common Equity Tier One Risk-Based Capital Ratio, Well Capitalized, Minimum	6.50%	6.50%
Tier 1 Capital to Risk-Weighted Assets, Actual, Capital Amount	$ 3,789,056	$ 3,261,532
Tier 1 Capital to Risk-Weighted Assets, Actual, Ratio	13%	12.72%
Tier One Risk Based Capital Required For Capital Adequacy Minimum Capital Required Plus Capital Conservation Buffer, Capital Amount	$ 2,477,614	$ 2,179,911
Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets Minimum Capital Required Plus Capital Conservation Buffer, Ratio	8.50%	8.50%	8.50%
Tier 1 Capital to Risk-Weighted Assets, Required to be Considered Well Capitalized, Capital Amount	$ 2,331,872	$ 2,051,681
Tier 1 Capital to Risk-Weighted Assets, Required to be Considered Well Capitalized, Ratio	8%	8%
Total Capital to Risk-Weighted Assets, Actual, Capital Amount	$ 4,023,386	$ 3,491,281
Total Capital to Risk-Weighted Assets, Actual, Ratio	13.80%	13.61%	8%
Capital Required for Capital Adequacy Minimum Capital Required Plus Capital Conservation Buffer, Capital Amount	$ 3,060,583	$ 2,692,831
Capital Required for Capital Adequacy to Risk Weighted Assets Minimum Capital Required Plus Capital Conservation Buffer, Ratio	10.50%	10.50%	10.50%
Total Capital to Risk-Weighted Assets, Required to be Considered Well Capitalized, Capital Amount	$ 2,914,841	$ 2,564,601
Total Capital to Risk-Weighted Assets, Required to be Considered Well Capitalized, Ratio	10%	10%
Leverage Ratio, Actual, Capital Amount	$ 3,789,056	$ 3,261,532
Leverage Ratio, Actual, Ratio	7.09%	6.80%
Tier One Leverage Capital Required for Capital Adequacy Minimum Capital Required Plus Capital Conservation Buffer, Capital Amount	$ 2,136,316	$ 1,917,679
Tier One Leverage Capital Required for Capital Adequacy to Average Assets Minimum Capital Required Plus Capital Conservation Buffer, Ratio	4%	4%	4%
Leverage Ratio, Required to be Considered Well Capitalized, Capital Amount	$ 2,670,395	$ 2,397,099
Leverage Ratio, Required to be Considered Well Capitalized, Ratio	5%	5%

Earnings Per Common Share (Basi

Earnings Per Common Share (Basic and Diluted Earnings Per Common Share) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Earnings Per Share [Abstract]
Net income	$ 579,150	$ 443,079	$ 331,151
Less: Preferred stock dividends	6,675	7,157	2,016
Redemption of preferred stock	0	0	5,514
Net income available to common shareholders	572,475	435,922	323,621
Less: Earnings allocated to participating securities	5,210	3,881	3,136
Net earnings allocated to common stock	567,265	432,041	320,485
Distributed earnings allocated to common stock	207,924	187,202	178,863
Undistributed earnings allocated to common stock	$ 359,341	$ 244,839	$ 141,622
Weighted-average shares outstanding for basic earnings per common share	64,156,870	63,612,658	62,727,053
Dilutive effect of stock compensation	363,648	489,462	276,784
Weighted-average shares outstanding for diluted earnings per common share	64,520,518	64,102,120	63,003,837

Employee Benefit Plans (Narrati

Employee Benefit Plans (Narrative) (Detail) - USD ($)	12 Months Ended
Employee Benefit Plans (Narrative) (Detail) - USD ($)	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Percentage of equity investments in mutual fund	67%
Net periodic benefit cost, Expected return on plan assets	7.25%	7.25%	7.25%
Expected defined benefit plans contribution within a year	$ 1,200,000
Defined contribution plan, cost	$ 28,000,000	$ 23,800,000
Number of stock plans	3
Dividends, share-based compensation	$ 0.87	$ 0.75	$ 0.72
Weighted-average risk-free interest rate	4.45%	0.77%	0.19%
Options awarded during period	0	0	0
Performance Shares [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Share-based compensation arrangement by share-based payment award, number of shares available for grant	505,456
Base-year adjusted net revenue amount	$ 713,800,000	$ 415,900,000
Base-year calculation basis point adjustment	0.30%	0.30%
Percentage level of achievement - 13 percent average growth	13%	13%
Award payout percentage of target at 50 percent	50%	50%
Percentage level of achievement - 19 percent average growth	19%	19%
Award payout percentage of target at 100 percent	100%	100%
Percentage level of achievement - 25 percent average growth	25%	25%
Award payout percentage of target at 150 percent	150%	150%
Award payout percentage at less than 25th percentile level of achievement	0%
Award payout percentage at the 25th percentile level of achievement	50%
Award payout percentage at the 50th percentile level of achievement	100%
Award payout percentage at the 75th percentile level of achievement	150%
Performance Shares [Member] \| Pro Forma [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Granted in period, number of shares/units	35,015	30,723	48,409
Equity Securities [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Target asset allocation percentage	64%
Fixed Income Securities [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Target asset allocation percentage	31%
Two Thousand Fifteen Plan [Member] \| Stock Options [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period	10 years
Vesting period of options awarded, years	4 years
Two Thousand Fifteen Plan [Member] \| Non Vested Stock Awards and Stock Units [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period	10 years
Two Thousand Fifteen Plan [Member] \| Non Vested Stock Awards and Stock Units [Member] \| 2021
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Vesting period of options awarded, years	3 years
Two Thousand Fifteen Plan [Member] \| Non Vested Stock Awards and Stock Units [Member] \| Prior to 2021
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Vesting period of options awarded, years	4 years
Minimum [Member] \| Performance Shares [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Percentage level of achievement - less than 13 percent average growth	13%	13%
Award payout percentage of target at 0 percent	0%	0%
Maximum [Member] \| Performance Shares [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Granted in period, number of shares/units	52,527	46,086	72,618
Other Pension Plan [Member] \| Qualified Plan [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Participants contribution eligible for match	100%
Defined contribution plan, cost			$ 17,900,000
Other Pension Plan [Member] \| Qualified Plan [Member] \| Minimum [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Maximum annual contributions per employee, percent	2%
Other Pension Plan [Member] \| Qualified Plan [Member] \| Maximum [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Maximum annual contributions per employee, percent	50%
Employer matching contribution, percent of employees' gross pay	6%

Employee Benefit Plans (Combine

Employee Benefit Plans (Combined Activity in Corporations Defined Benefit Pension Plans) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Retirement Benefits [Abstract]
Fair value of plan assets at beginning of year	$ 197,747	$ 182,088	$ 174,173
Actual return on plan assets	(26,108)	24,908	16,599
Employer contributions	1,114	1,236	1,201
Benefits paid	(10,930)	(10,485)	(9,885)
Fair value of plan assets at end of year	161,823	197,747	182,088
Benefit obligation at beginning of year	185,925	197,593	186,641
Interest cost	4,017	3,341	5,010
Actuarial (gain) loss	(35,068)	(4,524)	15,827
Benefits paid	(10,930)	(10,485)	(9,885)
Benefit obligation at end of year	143,944	185,925	197,593
Funded status of the plan at end of year and accrued benefit (liability) recognized	17,879	11,822	(15,505)
Accumulated benefit obligation at end of year	$ 143,944	$ 185,925	$ 197,593

Employee Benefit Plans (Disaggr

Employee Benefit Plans (Disaggregated Information Related to Corporations Defined Benefit Pension Plans) (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	$ 143,944	$ 185,925	$ 197,593	$ 186,641
Accumulated benefit obligation	143,944	185,925	197,593
Fair value of plan assets	161,823	197,747	182,088	$ 174,173
Funded status of the plan at end of year and accrued benefit (liability) recognized	17,879	11,822	$ (15,505)
Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	131,648	170,389
Accumulated benefit obligation	131,648	170,389
Fair value of plan assets	161,823	197,747
Funded status of the plan at end of year and accrued benefit (liability) recognized	30,175	27,358
Restoration Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	12,296	15,536
Accumulated benefit obligation	12,296	15,536
Fair value of plan assets	0	0
Funded status of the plan at end of year and accrued benefit (liability) recognized	$ (12,296)	$ (15,536)

Employee Benefit Plans (Net Per

Employee Benefit Plans (Net Periodic Benefit Cost (Benefit)) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Retirement Benefits [Abstract]
Expected return on plan assets, net of expenses	$ (13,966)	$ (12,839)	$ (12,289)
Interest cost on projected benefit obligation	4,017	3,341	5,010
Net amortization and deferral	2,964	6,116	5,319
Net periodic expense (benefit)	$ (6,985)	$ (3,382)	$ (1,960)

Employee Benefit Plans (Defined

Employee Benefit Plans (Defined Benefit Pension Plans Recognized as Component of Other Comprehensive Income) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Net actuarial gain (loss)	$ (2,041)	$ 22,709	$ (6,199)
Deferred tax (expense) benefit	429	(4,769)	1,302
Other comprehensive income (loss), net of tax	$ (1,612)	$ 17,940	$ (4,897)

Employee Benefit Plans (Defin_2

Employee Benefit Plans (Defined Benefit Pension Plans not Recognized as Component of Combined Net Period Benefit Cost) (Detail) - Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss	$ (43,675)	$ (41,634)
Deferred tax benefit	9,172	8,743
Amounts included in accumulated other comprehensive loss, net of tax	$ (34,503)	$ (32,891)

Employee Benefit Plans (Weighte

Employee Benefit Plans (Weighted-Average Assumptions Used to Determine Benefit Obligations) (Detail)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Retirement Benefits [Abstract]
Benefit obligations, Discount rate	5.14%	2.79%	2.43%
Net periodic benefit cost, Discount rate	2.79%	2.43%	3.20%
Net periodic benefit cost, Expected return on plan assets	7.25%	7.25%	7.25%

Employee Benefit Plans (Fair Va

Employee Benefit Plans (Fair Value of Plan Assets) (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 161,823	$ 197,747	$ 182,088	$ 174,173
Mutual Funds [Member] \| Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	154,391	195,452
Cash and Cash Equivalents [Member] \| Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 7,432	$ 2,295

Employee Benefit Plans (Expecte

Employee Benefit Plans (Expected Future Benefit Payments Related to Defined Benefit Plans) (Detail) $ in Thousands	Dec. 31, 2022 USD ($)
Retirement Benefits [Abstract]
2023	$ 11,864
2024	12,128
2025	12,059
2026	11,995
2027	11,848
2028 through 2032	55,245
Total defined benefit plan expected future benefit payments	$ 115,139

Employee Benefit Plans (Summary

Employee Benefit Plans (Summary of Activity in Corporation's Active Stock Plans) (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options exercised, number of shares	(399,810)	(987,758)	(408,563)
Director deferred stock units outstanding [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Ending balance, number of shares/units	45,661	56,301	52,860
Beginning balance, number of shares/units	56,301	52,860	55,370
Ending balance, weighted-average grant-date fair value	$ 87.15	$ 79.21	$ 75.47
Beginning balance, weighted-average grant-date fair value	$ 79.21	$ 75.47	$ 74.76
Granted in period, number of shares/units	5,382	5,940	10,428
Granted in period, weighted-average grant-date fair value	$ 133.67	$ 117.90	$ 73.84
Stock awards exercised/vested in period, number of shares	(16,022)	(2,499)	(12,938)
Stock awards exercised/vested in period, weighted-average grant date fair value	$ 74.89	$ 92.03	$ 71.09
Non-Vested Stock Awards/ Stock Units Outstanding [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Ending balance, number of shares/units	465,319	449,337	470,359
Beginning balance, number of shares/units	449,337	470,359	440,647
Ending balance, weighted-average grant-date fair value	$ 105.36	$ 93.05	$ 86.24
Beginning balance, weighted-average grant-date fair value	$ 93.05	$ 86.24	$ 90.22
Granted in period, number of shares/units	119,176	95,258	151,038
Granted in period, weighted-average grant-date fair value	$ 142.56	$ 130.36	$ 66.79
Stock awards exercised/vested in period, number of shares	(97,154)	(88,250)	(117,990)
Stock awards exercised/vested in period, weighted-average grant date fair value	$ 94.81	$ 98.90	$ 76.07
Forfeited/expired in period, number of shares/units	(6,040)	(28,030)	(3,336)
Forfeited/expired in period, weighted-average grant date fair value	$ 93.28	$ 87.08	$ 91.07
Share-based Payment Arrangement, Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Ending balance, number of shares	616,227	877,681	1,739,559
Beginning balance, number of shares	877,681	1,739,559	1,980,866
Ending balance, weighted-average exercise price	$ 71.27	$ 69.02	$ 66.11
Beginning balance, weighted-average exercise price	$ 69.02	$ 66.11	$ 64.60
Stock options exercised, number of shares	(261,454)	(861,878)	(235,880)
Stock options exercised, weighted-average exercise price	$ 63.72	$ 63.14	$ 53.23
Forfeited/expired, number of shares			(5,427)
Forfeited/expired, weighted-average exercise price			$ 75.74
Maximum [Member] \| Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Ending balance, number of shares/units	213,749	202,460	201,257
Beginning balance, number of shares/units	202,460	201,257	177,288
Ending balance, weighted-average grant-date fair value	$ 96.20	$ 84.71	$ 77.18
Beginning balance, weighted-average grant-date fair value	$ 84.71	$ 77.18	$ 83.48
Granted in period, number of shares/units	52,527	46,086	72,618
Granted in period, weighted-average grant-date fair value	$ 133.40	$ 121.46	$ 57.89
Stock awards exercised/vested in period, number of shares	(25,180)	(35,131)	(41,755)
Stock awards exercised/vested in period, weighted-average grant date fair value	$ 87.18	$ 92.27	$ 69.70
Forfeited/expired in period, number of shares/units	(16,058)	(9,752)	(6,894)
Forfeited/expired in period, weighted-average grant date fair value	$ 87.18	$ 75.70	$ 81.33

Employee Benefit Plans (Options

Employee Benefit Plans (Options Outstanding and Exercisable) (Detail) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($) $ / shares shares
65.01 - 70.00 [Member]
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Range of Exercise Prices, Minimum	$ 65.01
Range of Exercise Prices, Maximum	70
70.01 - 75.00 [Member]
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Range of Exercise Prices, Minimum	70.01
Range of Exercise Prices, Maximum	75
75.01 - 80.00 [Member]
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Range of Exercise Prices, Minimum	75.01
Range of Exercise Prices, Maximum	$ 80
Options Outstanding [Member]
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Number of Shares, Options Outstanding \| shares	616,227
Weighted-Average Exercise Price, Options Outstanding	$ 71.27
Weighted- Average Remaining Contractual Life in Years	2 years 29 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value \| $	$ 38,470
Options Outstanding [Member] \| 65.01 - 70.00 [Member]
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Number of Shares, Options Outstanding \| shares	277,131
Weighted-Average Exercise Price, Options Outstanding	$ 65.11
Weighted- Average Remaining Contractual Life in Years	2 years 9 months 25 days
Options Outstanding [Member] \| 70.01 - 75.00 [Member]
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Number of Shares, Options Outstanding \| shares	117,686
Weighted-Average Exercise Price, Options Outstanding	$ 71.39
Weighted- Average Remaining Contractual Life in Years	9 months 29 days
Options Outstanding [Member] \| 75.01 - 80.00 [Member]
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Number of Shares, Options Outstanding \| shares	221,410
Weighted-Average Exercise Price, Options Outstanding	$ 78.92
Weighted- Average Remaining Contractual Life in Years	1 year 9 months 29 days
Options Exercisable [Member]
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Number of Shares, Options Exercisable \| shares	616,227
Weighted-Average Exercise Price, Options Exercisable	$ 71.27
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value \| $	$ 38,470
Options Exercisable [Member] \| 65.01 - 70.00 [Member]
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Number of Shares, Options Exercisable \| shares	277,131
Weighted-Average Exercise Price, Options Exercisable	$ 65.11
Options Exercisable [Member] \| 70.01 - 75.00 [Member]
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Number of Shares, Options Exercisable \| shares	117,686
Weighted-Average Exercise Price, Options Exercisable	$ 71.39
Options Exercisable [Member] \| 75.01 - 80.00 [Member]
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Number of Shares, Options Exercisable \| shares	221,410
Weighted-Average Exercise Price, Options Exercisable	$ 78.92

Employee Benefit Plans (Shares

Employee Benefit Plans (Shares Issued in Connection with Stock Compensation Awards) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Retirement Benefits [Abstract]
New shares issued from available authorized shares	118,389	0	0
Shares issued from available treasury stock	281,421	987,758	408,563
Total	399,810	987,758	408,563
Proceeds from stock option exercises	$ 16,659	$ 54,417	$ 12,557
Intrinsic value of stock options exercised	19,616	43,904	5,365
Fair value of stock awards/units vested	$ 19,308	$ 15,751	$ 12,773

Employee Benefit Plans (Stock-B

Employee Benefit Plans (Stock-Based Compensation Expense) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-Based Payment Arrangement, Expense	$ 18,322	$ 12,753	$ 13,918
Income tax benefit	2,969	1,713	2,142
Non-Vested Stock Awards/ Stock Units Outstanding [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Non-vested stock awards/stock units	13,162	9,977	10,240
Director deferred stock units outstanding [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Non-vested stock awards/stock units	720	700	770
Performance Shares [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Non-vested stock awards/stock units	$ 4,440	$ 2,076	$ 2,908

Employee Benefit Plans (Unrecog

Employee Benefit Plans (Unrecognized Stock-Based Compensation Expense) (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($)
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Non-vested stock awards/stock units	$ 21,770
Performance stock units	11,078
Total	$ 32,848
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition	2 years 1 month 24 days
Employee service share-based compensation, Performance stock units,compensation cost not yet recognized,period for recognition	1 year 9 months 18 days

Other Non-Interest Income and_3

Other Non-Interest Income and Expense (Narrative) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Other Income and Expenses [Abstract]
Minimum percentage of the aggregate total net interest income and total non interest income required for amounts to be stated separately	1%	1%	1%
Payment for services provided by related party	$ 545	$ 257	$ 551

Other Non-Interest Income and_4

Other Non-Interest Income and Expense (Other Non-Interest Income and Expense) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Other Income and Expenses [Abstract]
Other	$ 45,217	$ 48,528	$ 47,712
Total other non-interest income	45,217	48,528	47,712
Professional services	40,908	34,747	37,253
Advertising, promotions and public relations	39,994	34,539	34,390
Other	113,319	102,171	94,667
Total other non-interest expense	$ 194,221	$ 171,457	$ 166,310

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Detail) - USD ($)	12 Months Ended
Income Taxes (Narrative) (Detail) - USD ($)	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
U.S. federal statutory income tax rate	21%	21%	21%
Unrecognized tax benefits	$ 0	$ 0	$ 0
Valuation allowance	$ 0	$ 0

Income Taxes (Income Tax Expens

Income Taxes (Income Tax Expense) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Current income tax expense	$ 94,595	$ 38,675	$ 36,002
Deferred income tax expense (benefit)	(4,918)	7,784	(15,832)
Income tax expense, as reported	$ 89,677	$ 46,459	$ 20,170
Effective tax rate	13.40%	9.50%	5.70%

Income Taxes (Income Tax Comput

Income Taxes (Income Tax Computed by Applying U.S. Federal Statutory Income Tax Rate) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income tax expense computed at the statutory rate	$ 140,454	$ 102,803	$ 73,777
Effect of tax-exempt interest	(50,602)	(50,740)	(51,624)
Net tax benefit from stock-based compensation	(4,602)	(7,877)	(852)
Tax benefit on dividends paid in our 401k plan	(1,854)	(1,764)	(1,851)
Bank owned life insurance income	(440)	(517)	(783)
Non-deductible FDIC premiums	3,277	2,629	1,790
Non-deductible compensation	2,250	1,773	1,123
Non-deductible meals and entertainment	683	625	786
Asset contribution to a charitable trust	0	0	(2,556)
Tax basis adjustment of premises and equipment	0	(1,026)	0
Other	511	553	360
Income tax expense, as reported	$ 89,677	$ 46,459	$ 20,170

Income Taxes (Schedule of Defer

Income Taxes (Schedule of Deferred Tax Assets and Liabilities) (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Lease liabilities under operating leases	$ 67,608	$ 65,815
Net unrealized loss on securities available for sale and transferred securities	349,237	0
Allowance for credit losses	60,137	62,819
Net actuarial loss on defined benefit post-retirement benefit plans	9,172	8,743
Stock-based compensation	6,622	6,989
Bonus accrual	11,204	7,506
Deferred loan and lease origination fees	3,675	3,118
Other	6,109	3,834
Total gross deferred tax assets	513,764	158,824
Net unrealized gain on securities available for sale and transferred securities	0	(101,067)
Right-of-use assets under operating leases	(60,651)	(59,415)
Premises and equipment	(45,647)	(49,645)
Intangible assets	(17,732)	(16,595)
Defined benefit post-retirement benefit plans	(12,730)	(11,027)
Other	(2,601)	(2,323)
Total gross deferred tax liabilities	(139,361)	(240,072)
Deferred Tax Assets, Net	$ 374,403
Deferred Tax Liabilities, Net		$ (81,248)

Other Comprehensive Income (L_3

Other Comprehensive Income (Loss) (Component of Other Comprehensive Income (Loss)) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Equity [Abstract]
Securities available for sale and transferred securities, Change in net unrealized gain/loss during the period, before tax amount	$ (2,143,567)	$ (231,355)	$ 427,331
Securities available for sale and transferred securities, Change in net unrealized gain on securities transferred to held to maturity, before tax amount	(737)	(971)	(1,256)
Securities available for sale and transferred securities, Reclassification adjustment for net (gains) losses included in net income, before tax amount	0	(69)	(108,989)
Total securities available for sale and transferred securities before tax amount	(2,144,304)	(232,395)	317,086
Change in the net actuarial gain/loss before tax amount	(5,005)	16,593	(11,518)
Reclassification adjustment for net amortization of actuarial gain/loss included in net income as a component of net periodic cost (benefit) before tax amount	2,964	6,116	5,319
Total defined-benefit post-retirement benefit plans	(2,041)	22,709	(6,199)
Other comprehensive income (loss), before tax	(2,146,345)	(209,686)	310,887
Securities available for sale and transferred securities, Change in net unrealized gain/loss during the period, tax expense (benefit)	(450,149)	(48,585)	89,741
Securities available for sale and transferred securities, change in net unrealized gain on securities transfers to held-to-maturity, tax expense benefit	(155)	(204)	(264)
Securities available for sale and transferred securities, Reclassification adjustment for net (gains) losses included in net income, tax expense (benefit)	0	(14)	(22,888)
Total securities available for sale and transferred securities, tax expense (benefit)	(450,304)	(48,803)	66,589
Change in the net actuarial gain/loss, tax expense (benefit)	(1,051)	3,485	(2,419)
Reclassification adjustment for net amortization of actuarial gain/loss included in net income as a componet of net periodic cost (benefit) , tax expense (benefit)	622	1,284	1,117
Total defined-benefit post-retirement benefit plans, tax expense (benefit)	(429)	4,769	(1,302)
Total other comprehensive income, tax expense (benefit)	(450,733)	(44,034)	65,287
Securities available for sale and transferred securities, change in net unrealized gain/loss during the period, net of tax amount	(1,693,418)	(182,770)	337,590
Securities available for sale and transferred securities. change in net unrealized gain on securities transfers to held-to-maturity, net of tax amount	(582)	(767)	(992)
Securities available for sale and securities transferred, reclassification adjustment for net (gains) losses included in net income, net of tax amount	0	(55)	(86,101)
Total securities available for sale and transferred securities, net of tax amount	(1,694,000)	(183,592)	250,497
Change in the net actuarial gain/loss, net of tax amount	(3,954)	13,108	(9,099)
Reclassification adjustment for net amortization of actuarial gain/loss included in net income as a componet of net periodic cost (benefit), net of tax amount	2,342	4,832	4,202
Total defined-benefit post-retirement benefit plans, net of tax amount	(1,612)	17,940	(4,897)
Other comprehensive income (loss), net of tax	$ (1,695,612)	$ (165,652)	$ 245,600

Other Comprehensive Income (Sch

Other Comprehensive Income (Schedule of Accumulated Other Comprehensive Income, Net of Tax) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	$ 347,318
Net other comprehensive income (loss) during period	(1,695,612)	$ (165,652)	$ 245,600
Ending Balance	(1,348,294)	347,318
Available-for-sale Securities [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	380,209	563,801	313,304
Other comprehensive income (loss) before reclassification	(1,694,000)	(183,537)	336,598
Reclassification of amounts included in net income	0	(55)	(86,101)
Net other comprehensive income (loss) during period	(1,694,000)	(183,592)	250,497
Ending Balance	(1,313,791)	380,209	563,801
Defined Benefit Plans [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	(32,891)	(50,831)	(45,934)
Other comprehensive income (loss) before reclassification	(3,954)	13,108	(9,099)
Reclassification of amounts included in net income	2,342	4,832	4,202
Net other comprehensive income (loss) during period	(1,612)	17,940	(4,897)
Ending Balance	(34,503)	(32,891)	(50,831)
AOCI Attributable to Parent [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	347,318	512,970	267,370
Other comprehensive income (loss) before reclassification	(1,697,954)	(170,429)	327,499
Reclassification of amounts included in net income	2,342	4,777	(81,899)
Net other comprehensive income (loss) during period	(1,695,612)	(165,652)	245,600
Ending Balance	$ (1,348,294)	$ 347,318	$ 512,970

Derivative Financial Instrume_3

Derivative Financial Instruments (Narrative) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Derivative [Line Items]
Weighted-average strike rate for outstanding interest rate caps	3.26%
Approximate credit exposure related to swaps with bank customers	$ 43,600
Cash collateral on deposit with other financial institutions	3,200	$ 110,300
Securities Loaned, Fair Value of Collateral	8,500
Interest Rate Swaps With Upstream Financial Institution Counterparties [Member]
Derivative [Line Items]
Approximate credit exposure related to swaps with bank customers	2,900
Not Designated as Hedging Instrument [Member] \| Financial Institution Counterparties Loan Lease Interest Rate Swaps Liabilities [Member]
Derivative [Line Items]
Estimated fair value of derivative contracts cleared through Chicago Mercantile Exchange	0	0
Not Designated as Hedging Instrument [Member] \| Put Option [Member] \| Other Non-Interest Income [Member]
Derivative [Line Items]
Gains included in other income from the sale of put options	$ 0	$ 0	$ 5,992

Derivative Financial Instrume_4

Derivative Financial Instruments (Schedule of Notional Amounts and Estimated Fair Values of Interest Rate Derivative Contracts Outstanding) (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Designated as Hedging Instrument [Member] \| Financial Institution Counterparties Loan Lease Interest Rate Swaps Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Notional Amount	$ 1,614	$ 0
Estimated Fair Value	19	0
Designated as Hedging Instrument [Member] \| Financial Institution Counterparties Loan Lease Interest Rate Swaps Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Notional Amount	0	2,426
Estimated Fair Value	0	(34)
Not Designated as Hedging Instrument [Member] \| Financial Institution Counterparties Loan Lease Interest Rate Swaps Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Notional Amount	1,165,812	247,592
Estimated Fair Value	70,416	1,207
Not Designated as Hedging Instrument [Member] \| Financial Institution Counterparties Loan Lease Interest Rate Swaps Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Notional Amount	78,798	928,756
Estimated Fair Value	(1,102)	(19,142)
Not Designated as Hedging Instrument [Member] \| Financial Institution Counterparties Loan Lease Interest Rate Caps Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Notional Amount	246,442	270,431
Estimated Fair Value	15,256	3,239
Not Designated as Hedging Instrument [Member] \| Customer Counterparties Loan Lease Interest Rate Swaps Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Notional Amount	53,570	928,756
Estimated Fair Value	1,102	39,864
Not Designated as Hedging Instrument [Member] \| Customer Counterparties Loan Lease Interest Rate Swaps Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Notional Amount	1,175,563	247,592
Estimated Fair Value	(79,175)	(2,846)
Not Designated as Hedging Instrument [Member] \| Customer Counterparties Loan Lease Interest Rate Caps Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Notional Amount	246,442	270,431
Estimated Fair Value	$ (15,256)	$ (3,239)

Derivative Financial Instrume_5

Derivative Financial Instruments (Schedule of Weighted-Average Rates Paid and Received for Interest Rate Swaps Outstanding) (Detail)	Dec. 31, 2022
Weighted Average Interest Rate Paid [Member]
Short-duration Insurance Contracts, Discounted Liabilities [Line Items]
Fair value hedge loan/lease interest rate swaps	1.58%
Weighted-Average Interest Rate Received [Member]
Short-duration Insurance Contracts, Discounted Liabilities [Line Items]
Fair value hedge loan/lease interest rate swaps	4.12%
Financial Institution Counterparties [Member] \| Weighted Average Interest Rate Paid [Member]
Short-duration Insurance Contracts, Discounted Liabilities [Line Items]
Non-hedging interest rate swaps - financial institution counterparties	3.73%
Financial Institution Counterparties [Member] \| Weighted-Average Interest Rate Received [Member]
Short-duration Insurance Contracts, Discounted Liabilities [Line Items]
Non-hedging interest rate swaps - financial institution counterparties	5.29%
Customer Counterparties [Member] \| Weighted Average Interest Rate Paid [Member]
Short-duration Insurance Contracts, Discounted Liabilities [Line Items]
Non-hedging interest rate swaps - customer counterparties	5.28%
Customer Counterparties [Member] \| Weighted-Average Interest Rate Received [Member]
Short-duration Insurance Contracts, Discounted Liabilities [Line Items]
Non-hedging interest rate swaps - customer counterparties	3.72%

Derivative Financial Instrume_6

Derivative Financial Instruments (Schedule of Notional Amounts and Estimated Fair Values of Commodity Derivative Positions) (Detail) bbl in Thousands, MMBTU in Thousands, $ in Thousands	Dec. 31, 2022 USD ($) bbl MMBTU	Dec. 31, 2021 USD ($) MMBTU bbl
Financial Institution Counterparties [Member] \| Oil Commodity Derivative [Member]
Derivative Instruments [Line Items]
Oil/Natural Gas Derivative Assets Notional Amount \| bbl	4,024	4,809
Oil/Natural Gas Derivative Assets, Estimated Fair Value	$ 27,082	$ 14,721
Oil/Natural Gas Derivative Liabilities Notional Amount \| bbl	6,068	7,032
Oil/Natural Gas Derivative Liabilities, Estimated Fair Value	$ (53,579)	$ (73,594)
Financial Institution Counterparties [Member] \| Natural Gas Commodity Derivative [Member]
Derivative Instruments [Line Items]
Oil/Natural Gas Derivative Assets Notional Amount \| MMBTU	16,539	15,947
Oil/Natural Gas Derivative Assets, Estimated Fair Value	$ 6,220	$ 4,143
Oil/Natural Gas Derivative Liabilities Notional Amount \| MMBTU	15,682	29,446
Oil/Natural Gas Derivative Liabilities, Estimated Fair Value	$ (19,138)	$ (21,249)
Customer Counterparties [Member] \| Oil Commodity Derivative [Member]
Derivative Instruments [Line Items]
Oil/Natural Gas Derivative Assets Notional Amount \| bbl	6,068	7,046
Oil/Natural Gas Derivative Assets, Estimated Fair Value	$ 54,219	$ 74,437
Oil/Natural Gas Derivative Liabilities Notional Amount \| bbl	4,024	4,796
Oil/Natural Gas Derivative Liabilities, Estimated Fair Value	$ (26,551)	$ (14,294)
Customer Counterparties [Member] \| Natural Gas Commodity Derivative [Member]
Derivative Instruments [Line Items]
Oil/Natural Gas Derivative Assets Notional Amount \| MMBTU	15,682	29,446
Oil/Natural Gas Derivative Assets, Estimated Fair Value	$ 19,164	$ 21,456
Oil/Natural Gas Derivative Liabilities Notional Amount \| MMBTU	16,539	15,947
Oil/Natural Gas Derivative Liabilities, Estimated Fair Value	$ (6,124)	$ (4,124)

Derivative Financial Instrume_7

Derivative Financial Instruments Derivative Financial Instruments (Schedule of Notional Amount and Fair Value of Open Foreign Currency Forward Contract) (Details) € in Thousands, $ in Thousands, $ in Thousands	Dec. 31, 2022 USD ($)	Dec. 31, 2022 EUR (€)	Dec. 31, 2022 CAD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2021 EUR (€)	Dec. 31, 2021 CAD ($)
Financial Institution Counterparties [Member] \| Other Assets [Member] \| Not Designated as Hedging Instrument [Member]
Derivative Counter Party [Line Items]
Forward Contracts - Assets, Notional Amount		€ 875	$ 0		€ 1,900	$ 658
Financial Institution Counterparties [Member] \| Other Liabilities [Member] \| Not Designated as Hedging Instrument [Member]
Derivative Counter Party [Line Items]
Forward Contracts Liability, Notional Amount \| €		875			0
Customer Counterparties [Member] \| Other Assets [Member] \| Not Designated as Hedging Instrument [Member]
Derivative Counter Party [Line Items]
Forward Contracts - Assets, Notional Amount		875	$ 0		0	$ 658
Customer Counterparties [Member] \| Other Liabilities [Member] \| Not Designated as Hedging Instrument [Member]
Derivative Counter Party [Line Items]
Forward Contracts Liability, Notional Amount \| €		€ 875			€ 1,900
GBP Foreign Exchange Forward [Member] \| Financial Institution Counterparties [Member]
Derivative Counter Party [Line Items]
Forward Contracts - Assets Estimated Fair Value	$ 1			$ 29
Forward Contracts, Liability Estimated Fair Value	(10)			0
GBP Foreign Exchange Forward [Member] \| Customer Counterparties [Member]
Derivative Counter Party [Line Items]
Forward Contracts - Assets Estimated Fair Value	10			0
Forward Contracts, Liability Estimated Fair Value	(1)			(55)
Foreign Exchange Forward [Member] \| Financial Institution Counterparties [Member]
Derivative Counter Party [Line Items]
Forward Contracts - Assets Estimated Fair Value	0			0
Foreign Exchange Forward [Member] \| Customer Counterparties [Member]
Derivative Counter Party [Line Items]
Forward Contracts - Assets Estimated Fair Value	$ 0			$ 4

Derivative Financial Instrume_8

Derivative Financial Instruments (Schedule of Amounts Related to Interest Rate Derivatives Designated as Hedges of Fair Value) (Detail) - Designated as Hedging Instrument [Member] - Commercial Loan/Lease Interest Rate Swaps [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Interest Income on Loans [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount included in income or expense	$ (7)	$ (91)	$ (111)
Other Non-Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount included in income or expense	$ 6	$ 10	$ 9

Derivative Financial Instrume_9

Derivative Financial Instruments (Schedule of Amounts Related to Non-Hedging Interest Rate and Commodity Derivatives) (Detail) - Not Designated as Hedging Instrument [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Interest Rate Contract [Member] \| Other Non-Interest Income [Member]
Other Non Interest Income Non Hedging Interest Rate Derivatives [Line Items]
Amount included in income or expense	$ 1,742	$ 4,285	$ 3,413
Interest Rate Contract [Member] \| Other Non-Interest Expense [Member]
Other Non Interest Income Non Hedging Interest Rate Derivatives [Line Items]
Amount included in income or expense	0	(1)	1
Commodity Contract [Member] \| Other Non-Interest Income [Member]
Other Non Interest Income Non Hedging Interest Rate Derivatives [Line Items]
Amount included in income or expense	2,297	4,052	1,768
Foreign Exchange Contract [Member] \| Other Non-Interest Income [Member]
Other Non Interest Income Non Hedging Interest Rate Derivatives [Line Items]
Amount included in income or expense	63	39	28
Put Option [Member] \| Other Non-Interest Income [Member]
Other Non Interest Income Non Hedging Interest Rate Derivatives [Line Items]
Amount included in income or expense	$ 0	$ 0	$ 5,992

Balance Sheet Offsetting - Fina

Balance Sheet Offsetting - Financial Instruments Eligible for Offset Consolidated Balance Sheet (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Gross Amount Recognized, Derivative, Financial Assets	$ 118,994	$ 23,339
Gross Amount Offset, Derivatives, Financial Assets	0	0
Net Amount Recognized, Derivative, Financial Assets	118,994	23,339
Gross Amount Recognized, Resell Agreements, Financial Assets	87,150	7,903
Gross Amount Offset, Resell Agreements, Financial Assets	0	0
Net Amount Recognized, Resell Agreements, Financial Assets	87,150	7,903
Gross Amount Recognized, Financial Assets	206,144	31,242
Gross Amount Offset, Financial Assets	0	0
Net Amount Recognized, Financial Assets	206,144	31,242
Gross Amount Recognized, Derivative, Financial Liabilities	73,829	114,019
Gross Amount Offset, Derivative, Financial Liabilities	0	0
Net Amount Recognized, Derivative, Financial Liabilities	73,829	114,019
Gross Amount Recognized, Repurchase Agreements, Financial Liabilities	4,660,641	2,740,799
Gross Amount Offset, Repurchase Agreements, Financial Liabilities	0	0
Net Amount Recognized, Repurchase Agreements, Financial Liabilities	4,660,641	2,740,799
Gross Amount Recognized, Financial Liabilities	4,734,470	2,854,818
Gross Amount Offset, Financial Liabilities	0	0
Net Amount Recognized, Financial Liabilities	4,734,470	2,854,818
Loan Lease Interest Rate Swaps And Caps [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Gross Amount Recognized, Derivative, Financial Assets	85,691	4,446
Gross Amount Offset, Derivatives, Financial Assets	0	0
Net Amount Recognized, Derivative, Financial Assets	85,691	4,446
Commodity Swaps And Options [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Gross Amount Recognized, Derivative, Financial Assets	33,302	18,864
Gross Amount Offset, Derivatives, Financial Assets	0	0
Net Amount Recognized, Derivative, Financial Assets	33,302	18,864
Gross Amount Recognized, Derivative, Financial Liabilities	72,717	94,843
Gross Amount Offset, Derivative, Financial Liabilities	0	0
Net Amount Recognized, Derivative, Financial Liabilities	72,717	94,843
Foreign Currency Forward Contracts [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Gross Amount Recognized, Derivative, Financial Assets	1	29
Gross Amount Offset, Derivatives, Financial Assets	0	0
Net Amount Recognized, Derivative, Financial Assets	1	29
Gross Amount Recognized, Derivative, Financial Liabilities	10
Gross Amount Offset, Derivative, Financial Liabilities	0
Net Amount Recognized, Derivative, Financial Liabilities	10
Loan Lease Interest Rate Swaps [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Gross Amount Recognized, Derivative, Financial Liabilities	1,102	19,176
Gross Amount Offset, Derivative, Financial Liabilities	0	0
Net Amount Recognized, Derivative, Financial Liabilities	$ 1,102	$ 19,176

Balance Sheet Offsetting - Fi_2

Balance Sheet Offsetting - Financial Instruments Derivative Assets Liabilities and Resell Agreements Net of Amount Not Offset (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Net Amount Recognized, Derivatives, Financial Assets	$ 118,994	$ 23,339
Gross Amounts Not Offset, Financial Instruments, Total Derivatives, Financial Assets	(62,528)	(23,339)
Gross Amounts Not Offset, Collateral, Derivatives, Financial Assets	(55,968)	0
Net Amount, Derivatives, Financial Assets	498	0
Net Amount Recognized, Resell Agreements, Financial Assets	87,150	7,903
Gross Amounts Not Offset, Financial Instruments, Resell Agreements, Financial Assets	0	0
Gross Amounts Not Offset, Collateral, Resell Agreements, Financial Assets	(87,150)	(7,903)
Net Amount, Resell Agreements, Financial Assets	0	0
Net Amount Recognized, Total Financial Assets	206,144	31,242
Gross Amounts Not Offset, Collateral, Financial Assets	(143,118)	(7,903)
Net Amount, Financial Assets	498	0
Net Amount Recognized, Derivatives, Financial Liabilities	73,829	114,019
Gross Amounts Not Offset, Financial Instruments, Total Derivatives, Financial Liabilities	(62,528)	(23,339)
Gross Amounts Not offset, Collateral, Derivatives, Financial Liabilities	(9,330)	(90,573)
Net Amount, Derivatives, Financial Liabilities	1,971	107
Net Amount Recognized, Repurchase Agreements, Financial Liabilities	4,660,641	2,740,799
Gross Amounts Not Offset, Financial Instruments, Repurchase Agreements, Financial Liabilities	0	0
Gross Amounts Not Offset, Collateral, Repurchase Agreements, Financial Liabilities	(4,660,641)	(2,740,799)
Net Amount, Repurchase Agreements, Financial Liabilities	0	0
Net Amount Recognized, Financial Liabilities	4,734,470	2,854,818
Gross Amounts Not Offset, Collateral, Financial Liabilities	(4,669,971)	(2,831,372)
Net Amount, Financial Liabilities	1,971	107
Counterparty B [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Net Amount Recognized, Derivatives, Financial Assets	39,370	7,655
Gross Amounts Not Offset, Financial Instruments, Total Derivatives, Financial Assets	(24,500)	(7,655)
Gross Amounts Not Offset, Collateral, Derivatives, Financial Assets	(14,870)	0
Net Amount, Derivatives, Financial Assets	0	0
Net Amount Recognized, Derivatives, Financial Liabilities	24,500	28,130
Gross Amounts Not Offset, Financial Instruments, Total Derivatives, Financial Liabilities	(24,500)	(7,655)
Gross Amounts Not offset, Collateral, Derivatives, Financial Liabilities	0	(20,475)
Net Amount, Derivatives, Financial Liabilities	0	0
Counterparty E
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Net Amount Recognized, Derivatives, Financial Assets	14,430	411
Gross Amounts Not Offset, Financial Instruments, Total Derivatives, Financial Assets	(47)	(411)
Gross Amounts Not Offset, Collateral, Derivatives, Financial Assets	(14,131)	0
Net Amount, Derivatives, Financial Assets	252	0
Net Amount Recognized, Derivatives, Financial Liabilities	47	601
Gross Amounts Not Offset, Financial Instruments, Total Derivatives, Financial Liabilities	(47)	(411)
Gross Amounts Not offset, Collateral, Derivatives, Financial Liabilities	0	(190)
Net Amount, Derivatives, Financial Liabilities	0	0
Counterparty F
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Net Amount Recognized, Derivatives, Financial Assets	17,297	12,078
Gross Amounts Not Offset, Financial Instruments, Total Derivatives, Financial Assets	(17,297)	(12,078)
Gross Amounts Not Offset, Collateral, Derivatives, Financial Assets	0	0
Net Amount, Derivatives, Financial Assets	0	0
Net Amount Recognized, Derivatives, Financial Liabilities	27,747	20,813
Gross Amounts Not Offset, Financial Instruments, Total Derivatives, Financial Liabilities	(17,297)	(12,078)
Gross Amounts Not offset, Collateral, Derivatives, Financial Liabilities	(8,479)	(8,735)
Net Amount, Derivatives, Financial Liabilities	1,971	0
Counterparty G
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Net Amount Recognized, Derivatives, Financial Assets	10,660	1,783
Gross Amounts Not Offset, Financial Instruments, Total Derivatives, Financial Assets	0	(1,783)
Gross Amounts Not Offset, Collateral, Derivatives, Financial Assets	(10,660)	0
Net Amount, Derivatives, Financial Assets	0	0
Net Amount Recognized, Derivatives, Financial Liabilities	0	1,789
Gross Amounts Not Offset, Financial Instruments, Total Derivatives, Financial Liabilities	0	(1,783)
Gross Amounts Not offset, Collateral, Derivatives, Financial Liabilities	0	(6)
Net Amount, Derivatives, Financial Liabilities	0	0
Other Counterparties [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Net Amount Recognized, Derivatives, Financial Assets	37,237	1,412
Gross Amounts Not Offset, Financial Instruments, Total Derivatives, Financial Assets	(20,684)	(1,412)
Gross Amounts Not Offset, Collateral, Derivatives, Financial Assets	(16,307)	0
Net Amount, Derivatives, Financial Assets	246	0
Net Amount Recognized, Derivatives, Financial Liabilities	21,535	62,686
Gross Amounts Not Offset, Financial Instruments, Total Derivatives, Financial Liabilities	(20,684)	(1,412)
Gross Amounts Not offset, Collateral, Derivatives, Financial Liabilities	(851)	(61,167)
Net Amount, Derivatives, Financial Liabilities	$ 0	$ 107

Balance Sheet Offsetting Bala_2

Balance Sheet Offsetting Balance Sheet Offsetting - Remaining Contractual Maturity of the Securities Sold Under Agreement to Repurchase (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Remaining Contractual Maturity of the Securities Sold Under Agreement to Repurchase [Line Items]
Remaining contractual maturity of the agreements overnight and continuous	$ 4,660,641	$ 2,740,799
Remaining contractual maturity of the agreements up to 30 Days	0	0
Remaining contractual maturity of the agreements 30 to 90 Days	0	0
Remaining contractual maturity of the agreements greater than 90 Days	0	0
Remaining contractual maturity of the agreements total	4,660,641	2,740,799
Securities Sold under Agreements to Repurchase, Gross	4,660,641	2,740,799
Securities Sold under Agreements to Repurchase, Collateral, Right to Reclaim Securities	0	0
US Treasury [Member]
Remaining Contractual Maturity of the Securities Sold Under Agreement to Repurchase [Line Items]
Remaining contractual maturity of the agreements overnight and continuous	3,735,061	1,342,591
Remaining contractual maturity of the agreements up to 30 Days	0	0
Remaining contractual maturity of the agreements 30 to 90 Days	0	0
Remaining contractual maturity of the agreements greater than 90 Days	0	0
Remaining contractual maturity of the agreements total	3,735,061	1,342,591
Residential Mortgage Backed Securities [Member]
Remaining Contractual Maturity of the Securities Sold Under Agreement to Repurchase [Line Items]
Remaining contractual maturity of the agreements overnight and continuous	925,580	1,398,208
Remaining contractual maturity of the agreements up to 30 Days	0	0
Remaining contractual maturity of the agreements 30 to 90 Days	0	0
Remaining contractual maturity of the agreements greater than 90 Days	0	0
Remaining contractual maturity of the agreements total	$ 925,580	$ 1,398,208

Fair Value Measurements (Narrat

Fair Value Measurements (Narrative) (Detail) $ in Thousands	Dec. 31, 2022 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial instruments using fair value measurement option	$ 0

Fair Value Measurements (Financ

Fair Value Measurements (Financial Assets and Financial Liabilities Measured at Fair Value on Recurring Basis) (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at estimated fair value	$ 18,243,605	$ 13,924,628
Trading account securities	28,045	25,162
Derivative assets:	118,994	23,339
Derivative liabilities:	73,829	114,019
Interest Rate Swaps Caps And Floors [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets:	86,793	44,310
Derivative liabilities:	95,533	25,261
Commodity Swaps And Options [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets:	106,685	114,757
Derivative liabilities:	105,392	113,261
Foreign Exchange Forward [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets:	11	33
Derivative liabilities:	11	55
US Treasury Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at estimated fair value	5,051,587	2,179,433
Trading account securities	25,879	24,237
Residential Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at estimated fair value	6,376,236	4,066,265
US States and Political Subdivisions Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at estimated fair value	6,773,355	7,636,571
Trading account securities	2,166	925
Other Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at estimated fair value	42,427	42,359
Level 1 [Member] \| Foreign Exchange Forward [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets:	11	33
Derivative liabilities:	11	55
Level 1 [Member] \| US Treasury Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at estimated fair value	5,051,587	2,179,433
Trading account securities	25,879	24,237
Level 2 [Member] \| Interest Rate Swaps Caps And Floors [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets:	86,793	44,310
Derivative liabilities:	95,533	25,261
Level 2 [Member] \| Commodity Swaps And Options [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets:	106,685	114,757
Derivative liabilities:	105,392	113,261
Level 2 [Member] \| Residential Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at estimated fair value	6,376,236	4,066,265
Level 2 [Member] \| US States and Political Subdivisions Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at estimated fair value	6,773,355	7,636,571
Trading account securities	2,166	925
Level 2 [Member] \| Other Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at estimated fair value	42,427	42,359
US Treasury Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at estimated fair value	5,051,587	2,179,433
Trading account securities	25,879	24,237
Residential Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at estimated fair value	6,376,236	4,066,265
US States and Political Subdivisions Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at estimated fair value	6,773,355	7,636,571
Trading account securities	2,166	925
Other Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at estimated fair value	$ 42,427	$ 42,359

Fair Value Measurements (Impair

Fair Value Measurements (Impaired Loans Remeasured and Reported at Fair Value of Underlying Collateral) (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying value before allocations	$ 6,237	$ 1,333	$ 1,559
Specific valuation allowance allocations	(1,480)		(450)
Reversal of specific valuation allowance allocations		214
Fair value	4,757	1,547	1,109
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying value before allocations	8,156	16,074	34,302
Specific valuation allowance allocations		(5,178)	(11,151)
Reversal of specific valuation allowance allocations	625
Fair value	$ 8,781	$ 10,896	$ 23,151

Fair Value Measurements (Estima

Fair Value Measurements (Estimated Fair Values of Financial Instruments) (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash and cash equivalents	$ 12,028,132	$ 16,583,000	$ 10,288,853	$ 3,788,181
Securities held to maturity	2,639,083	1,749,179
Loans, net	16,927,348	16,087,731
Deposits	43,954,196	42,695,696
Federal funds purchased	51,650	25,925
Repurchase agreements	4,660,641	2,740,799
Junior subordinated deferrable interest debentures	123,069	123,011
Subordinated notes	99,335	99,178
Carrying Amount [Member] \| Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash and cash equivalents	12,028,132	16,583,000
Securities held to maturity	2,639,083	1,749,179
Cash surrender value of life insurance policies	190,188	190,139
Accrued interest receivable	243,682	179,111
Deposits	43,954,196	42,695,696
Federal funds purchased	51,650	25,925
Repurchase agreements	4,660,641	2,740,799
Junior subordinated deferrable interest debentures	123,069	123,011
Subordinated notes	99,335	99,178
Accrued interest payable	18,444	3,026
Carrying Amount [Member] \| Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans, net	16,927,348	16,087,731
Estimated Fair Value [Member] \| Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash and cash equivalents	12,028,132	16,583,000
Securities held to maturity	2,467,865	1,809,143
Cash surrender value of life insurance policies	190,188	190,139
Accrued interest receivable	243,682	179,111
Deposits	43,920,741	41,343,426
Federal funds purchased	51,650	25,925
Repurchase agreements	4,660,641	2,740,799
Junior subordinated deferrable interest debentures	123,712	123,712
Subordinated notes	97,014	111,430
Accrued interest payable	18,444	3,026
Estimated Fair Value [Member] \| Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans, net	$ 16,343,417	$ 16,079,454

Operating Segments Operating Se

Operating Segments Operating Segments - Additional Information (Details) $ in Billions	12 Months Ended
	Dec. 31, 2022 USD ($) Segment	Dec. 31, 2021 USD ($) Segment	Dec. 31, 2020 USD ($) Segment
Segment Reporting Information [Line Items]
Number of operating segments \| Segment	2	2	2
Frost Wealth Advisors [Member]
Segment Reporting Information [Line Items]
Fair value of off-balance sheet managed and custody assets \| $	$ 43.6	$ 43.3	$ 38.6

Operating Segments (Summary of

Operating Segments (Summary of Operating Results by Segment) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Segment Reporting Information [Line Items]
Net interest income (expense)	$ 1,291,283	$ 984,867	$ 976,001
Credit loss expense	3,000	63	241,230
Non-interest income	404,818	386,728	465,454
Non-interest expense	1,024,274	881,994	848,904
Income before income taxes	668,827	489,538	351,321
Income tax expense (benefit)	89,677	46,459	20,170
Net income	579,150	443,079	331,151
Preferred stock dividends	6,675	7,157	2,016
Redemption of preferred stock	0	0	5,514
Net income available to common shareholders	572,475	435,922	323,621
Revenues from (expenses to) external customers	1,696,101	1,371,595	1,441,455
Average assets	51,513,000	45,983,000	37,961,000
Banking [Member]
Segment Reporting Information [Line Items]
Net interest income (expense)	1,295,467	989,870	981,441
Credit loss expense	3,000	54	241,230
Non-interest income	230,876	220,662	321,136
Non-interest expense	886,421	753,719	718,519
Income before income taxes	636,922	456,759	342,828
Income tax expense (benefit)	85,127	41,483	20,347
Net income	551,795	415,276	322,481
Preferred stock dividends	0	0	0
Redemption of preferred stock			0
Net income available to common shareholders	551,795	415,276	322,481
Revenues from (expenses to) external customers	1,526,343	1,210,532	1,302,577
Average assets	51,448,000	45,903,000	37,892,000
Frost Wealth Advisors [Member]
Segment Reporting Information [Line Items]
Net interest income (expense)	4,645	2,138	2,776
Credit loss expense	0	9	0
Non-interest income	175,874	167,442	145,268
Non-interest expense	132,009	122,972	123,630
Income before income taxes	48,510	46,599	24,414
Income tax expense (benefit)	10,187	9,786	5,127
Net income	38,323	36,813	19,287
Preferred stock dividends	0	0	0
Redemption of preferred stock			0
Net income available to common shareholders	38,323	36,813	19,287
Revenues from (expenses to) external customers	180,519	169,580	148,044
Average assets	57,000	70,000	59,000
Non-Banks [Member]
Segment Reporting Information [Line Items]
Net interest income (expense)	(8,829)	(7,141)	(8,216)
Credit loss expense	0	0	0
Non-interest income	(1,932)	(1,376)	(950)
Non-interest expense	5,844	5,303	6,755
Income before income taxes	(16,605)	(13,820)	(15,921)
Income tax expense (benefit)	(5,637)	(4,810)	(5,304)
Net income	(10,968)	(9,010)	(10,617)
Preferred stock dividends	6,675	7,157	2,016
Redemption of preferred stock			5,514
Net income available to common shareholders	(17,643)	(16,167)	(18,147)
Revenues from (expenses to) external customers	(10,761)	(8,517)	(9,166)
Average assets	$ 8,000	$ 10,000	$ 10,000

Condensed Financial Statement_3

Condensed Financial Statements of Parent Company (Schedule of Condensed Balance Sheets) (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Condensed Financial Statements, Captions [Line Items]
Cash	$ 691,553	$ 555,778
Total cash and cash equivalents	12,028,132	16,583,000	$ 10,288,853	$ 3,788,181
Total assets	52,892,376	50,878,490
Junior subordinated deferrable interest debentures, net of unamortized issuance costs	123,069	123,011
Subordinated notes, net of unamortized issuance costs	99,335	99,178
Accrued interest payable and other liabilities	866,257	754,326
Total liabilities	49,755,148	46,438,935
Shareholders’ Equity	3,137,228	4,439,555	4,293,016	3,911,668
Total liabilities and shareholders’ equity	52,892,376	50,878,490
Parent Company [Member]
Condensed Financial Statements, Captions [Line Items]
Cash	311,944	471,875
Total cash and cash equivalents	311,944	471,875	$ 381,240	$ 267,116
Investment in subsidiaries	3,065,114	4,222,288
Accrued interest receivable and other assets	1,142	2,228
Total assets	3,378,200	4,696,391
Junior subordinated deferrable interest debentures, net of unamortized issuance costs	123,069	123,011
Subordinated notes, net of unamortized issuance costs	99,335	99,178
Accrued interest payable and other liabilities	18,568	34,647
Total liabilities	240,972	256,836
Shareholders’ Equity	3,137,228	4,439,555
Total liabilities and shareholders’ equity	$ 3,378,200	$ 4,696,391

Condensed Financial Statement_4

Condensed Financial Statements of Parent Company (Schedule of Condensed Statements of Income) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Condensed Financial Statements, Captions [Line Items]
Total income	$ 1,475,721	$ 1,008,769	$ 1,021,035
Interest expense	184,438	23,902	45,034
Other	194,221	171,457	166,310
Income before income taxes and equity in undistributed earnings of subsidiaries	668,827	489,538	351,321
Income tax benefit	(89,677)	(46,459)	(20,170)
Net income	579,150	443,079	331,151
Preferred stock dividends	6,675	7,157	2,016
Redemption of preferred stock	0	0	5,514
Net income available to common shareholders	572,475	435,922	323,621
Parent Company [Member]
Condensed Financial Statements, Captions [Line Items]
Dividend income paid by Frost Bank	51,711	219,386	298,884
Dividend income paid by non-banks	109	473	736
Interest and other income	0	101	446
Total income	51,820	219,960	300,066
Interest expense	8,829	7,141	8,216
Salaries and employee benefits	1,605	1,499	1,581
Other	6,316	5,867	6,833
Total expenses	16,750	14,507	16,630
Income before income taxes and equity in undistributed earnings of subsidiaries	35,070	205,453	283,436
Income tax benefit	5,641	4,899	5,406
Equity in undistributed earnings of subsidiaries	538,439	232,727	42,309
Net income	579,150	443,079	331,151
Preferred stock dividends	6,675	7,157	2,016
Redemption of preferred stock	0	0	5,514
Net income available to common shareholders	$ 572,475	$ 435,922	$ 323,621

Condensed Financial Statement_5

Condensed Financial Statements of Parent Company (Schedule of Condensed Statements of Cash Flows) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Condensed Financial Statements, Captions [Line Items]
Net income	$ 579,150	$ 443,079	$ 331,151
Stock-based compensation	18,322	12,753	13,918
Net tax benefit from stock-based compensation	4,602	7,877	852
Net cash provided by (used in) operating activities	722,582	648,293	524,243
Net cash provided by (used in) investing activities	(8,277,330)	(2,525,015)	(1,631,047)
Principal payments on long-term borrowings	0	(13,403)	0
Redemption of Series A preferred stock	0	0	(150,000)
Proceeds from issuance of Series B preferred stock	0	0	145,452
Proceeds from stock option exercises	16,659	54,417	12,557
Purchase of treasury stock	(4,391)	(3,864)	(15,785)
Treasury stock issued to 401(k) stock purchase plan	0	1,749	10,307
Cash dividends paid on preferred stock	(6,675)	(7,157)	(2,016)
Cash dividends paid on common stock	(209,780)	(188,786)	(180,584)
Net cash provided by (used in) financing activities	2,999,880	8,170,869	7,607,476
Net change in cash and cash equivalents	(4,554,868)	6,294,147	6,500,672
Cash and cash equivalents at beginning of year	16,583,000	10,288,853	3,788,181
Cash and cash equivalents at end of year	12,028,132	16,583,000	10,288,853
Parent Company [Member]
Condensed Financial Statements, Captions [Line Items]
Net income	579,150	443,079	331,151
Equity in undistributed earnings of subsidiaries	(538,439)	(232,727)	(42,309)
Stock-based compensation	720	700	770
Net tax benefit from stock-based compensation	472	278	370
Net change in other assets and other liabilities	(15,249)	23,890	(8,937)
Net cash provided by (used in) operating activities	26,654	235,220	281,045
Redemption of investment in non-bank subsidiary	0	406	0
Net cash provided by (used in) investing activities	0	406	0
Principal payments on long-term borrowings	0	(13,403)	0
Redemption of Series A preferred stock	0	0	(150,000)
Proceeds from issuance of Series B preferred stock	0	0	145,452
Proceeds from stock option exercises	16,659	54,417	12,557
Proceeds from stock-based compensation activities of subsidiaries	17,602	12,053	13,148
Purchase of treasury stock	(4,391)	(3,864)	(15,785)
Treasury stock issued to 401(k) stock purchase plan	0	1,749	10,307
Cash dividends paid on preferred stock	(6,675)	(7,157)	(2,016)
Cash dividends paid on common stock	(209,780)	(188,786)	(180,584)
Net cash provided by (used in) financing activities	(186,585)	(144,991)	(166,921)
Net change in cash and cash equivalents	(159,931)	90,635	114,124
Cash and cash equivalents at beginning of year	471,875	381,240	267,116
Cash and cash equivalents at end of year	$ 311,944	$ 471,875	$ 381,240

Accounting Standards Updates Ac

Accounting Standards Updates Accounting Standards Update (Narrative) (Details) - USD ($) $ in Thousands	Jan. 01, 2020	Dec. 31, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of accounting change		$ (29,252)
Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of accounting change	$ (29,300)	$ (29,252)