Prosperity Bancshares (PB) 10-Q3 Nov 232023 Q3 Quarterly reportFinancial data

Company Profile

Document And Entity Information

Document And Entity Information - shares	9 Months Ended
Document And Entity Information - shares	Sep. 30, 2023	Oct. 30, 2023
Cover [Abstract]
Entity Registrant Name	PROSPERITY BANCSHARES, INC.
Entity Central Index Key	0001068851
Trading Symbol	PB
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Sep. 30, 2023
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding (in shares)		93,714,954
Entity Current Reporting Status	Yes
Entity File Number	001-35388
Entity Incorporation, State or Country Code	TX
Entity Tax Identification Number	74-2331986
Entity Address, Address Line One	Prosperity Bank Plaza
Entity Address, Address Line Two	4295 San Felipe
Entity Address, City or Town	Houston
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	77027
City Area Code	281
Local Phone Number	269-7199
Entity Shell Company	false
Entity Interactive Data Current	Yes
Title of 12(b) Security	Common stock, par value $1.00 per share
Security Exchange Name	NYSE
Document Quarterly Report	true
Document Transition Report	false

Consolidated Balance Sheets (Un

Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
ASSETS
Cash and due from banks	$ 512,239	$ 423,832
Federal funds sold	234	301
Total cash and cash equivalents	512,473	424,133
Available for sale securities, at fair value	446,165	456,502
Held to maturity securities, at cost (fair value of $10,834,219 and $12,387,125, respectively)	12,746,577	14,019,503
Total securities	13,192,742	14,476,005
Loans held for sale	10,187	554
Loans held for investment	20,510,199	18,098,653
Loans held for investment - Warehouse Purchase Program	912,327	740,620
Total loans	21,432,713	18,839,827
Less: allowance for credit losses on loans	(351,495)	(281,576)
Loans, net	21,081,218	18,558,251
Accrued interest receivable	97,006	88,438
Goodwill	3,396,459	3,231,636
Core deposit intangibles, net	67,553	51,348
Bank premises and equipment, net	370,237	339,453
Other real estate owned	9,320	1,963
Bank owned life insurance (BOLI)	379,498	327,439
Federal Home Loan Bank of Dallas stock	69,541	90,025
Other assets	119,637	101,138
TOTAL ASSETS	39,295,684	37,689,829
Deposits:
Noninterest-bearing	10,281,893	10,915,448
Interest-bearing	17,030,907	17,618,083
Total deposits	27,312,800	28,533,531
Other borrowings	4,250,000	1,850,000
Securities sold under repurchase agreements	300,714	428,134
Accrued interest payable	79,561	4,495
Allowance for credit losses on off-balance sheet credit exposures	36,503	29,947
Other liabilities	283,429	144,348
Total liabilities	32,263,007	30,990,455
COMMITMENTS AND CONTINGENCIES
SHAREHOLDERS’ EQUITY:
Preferred stock, $1 par value; 20,000,000 shares authorized; none issued or outstanding
Common stock, $1 par value; 200,000,000 shares authorized; 93,717,454 issued and outstanding at September 30, 2023; 91,313,615 shares issued and outstanding at December 31, 2022	93,718	91,314
Capital surplus	3,700,675	3,541,924
Retained earnings	3,240,214	3,069,609
Accumulated other comprehensive loss - net unrealized loss on available for sale securities, net of tax benefit of $(513) and $(923), respectively	(1,930)	(3,473)
Total shareholders’ equity	7,032,677	6,699,374
TOTAL LIABILITIES AND SHAREHOLDERS’ EQUITY	$ 39,295,684	$ 37,689,829

Consolidated Balance Sheets (_2

Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Held to maturity securities, fair value	$ 10,834,219	$ 12,387,125
Preferred stock, par value (in dollars per share)	$ 1	$ 1
Preferred stock, shares authorized (in shares)	20,000,000	20,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 1	$ 1
Common stock, shares authorized (in shares)	200,000,000	200,000,000
Common stock, shares issued (in shares)	93,717,454	91,313,615
Common stock, shares outstanding (in shares)	93,717,454	91,313,615
Accumulated other comprehensive loss net unrealized loss on available for sale securities, tax benefit	$ (513)	$ (923)

Consolidated Statements of Inco

Consolidated Statements of Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
INTEREST INCOME:
Loans, including fees	$ 308,678	$ 210,268	$ 842,434	$ 596,063
Securities	69,987	68,761	215,225	187,883
Federal funds sold and other earning assets	1,689	525	10,452	2,297
Total interest income	380,354	279,554	1,068,111	786,243
INTEREST EXPENSE:
Deposits	76,069	14,669	187,376	32,064
Other borrowings	62,190	3,719	153,937	4,169
Securities sold under repurchase agreements	2,533	487	7,310	916
Subordinated debentures	38		38
Total interest expense	140,830	18,875	348,661	37,149
NET INTEREST INCOME	239,524	260,679	719,450	749,094
PROVISION FOR CREDIT LOSSES			18,540
NET INTEREST INCOME AFTER PROVISION FOR CREDIT LOSSES	239,524	260,679	700,910	749,094
NONINTEREST INCOME:
Nonsufficient funds (NSF) fees	8,719	8,887	25,326	25,495
Credit card, debit card and ATM card income	9,285	8,889	27,157	25,948
Service charges on deposit accounts	6,262	6,222	18,266	18,798
Trust income	3,326	3,174	9,909	8,752
Mortgage income	857	340	1,756	1,297
Brokerage income	1,067	940	3,216	2,749
Net (loss) gain on sale or write-down of assets	(45)	50	2,070	1,847
Other	9,272	6,186	28,997	22,518
Total noninterest income	38,743	34,688	116,697	107,404
NONINTEREST EXPENSE:
Salaries and employee benefits	85,423	79,578	247,944	239,360
Net occupancy and equipment	9,464	8,412	26,424	24,299
Credit and debit card, data processing and software amortization	10,919	9,516	30,829	27,611
Regulatory assessments and FDIC insurance	5,155	2,807	15,225	8,508
Core deposit intangibles amortization	3,576	2,577	9,117	7,778
Depreciation	4,585	4,436	13,676	13,522
Communications	3,686	3,374	10,841	9,499
Net other real estate income	(581)	(15)	(1,033)	(213)
Merger related expenses	1,104		14,855
Other	12,326	11,529	36,649	34,578
Total noninterest expense	135,657	122,214	404,527	364,942
INCOME BEFORE INCOME TAXES	142,610	173,153	413,080	491,556
PROVISION FOR INCOME TAXES	30,402	37,333	89,240	104,920
NET INCOME	$ 112,208	$ 135,820	$ 323,840	$ 386,636
EARNINGS PER SHARE:
Basic	$ 1.2	$ 1.49	$ 3.5	$ 4.22
Diluted	$ 1.2	$ 1.49	$ 3.5	$ 4.22

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Statement of Comprehensive Income [Abstract]
Net income	$ 112,208	$ 135,820	$ 323,840	$ 386,636
Securities available for sale:
Change in unrealized income (loss) during the period	951	(1,813)	1,953	(2,587)
Total other comprehensive income (loss)	951	(1,813)	1,953	(2,587)
Deferred tax (expense) benefit related to other comprehensive income (loss)	(200)	380	(410)	543
Other comprehensive income (loss), net of tax	751	(1,433)	1,543	(2,044)
Comprehensive income	$ 112,959	$ 134,387	$ 325,383	$ 384,592

Consolidated Statements of Chan

Consolidated Statements of Changes in Shareholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock [Member]	Capital Surplus [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
BALANCE at Dec. 31, 2021	$ 6,427,236	$ 92,171	$ 3,595,023	$ 2,738,233	$ 1,809
BALANCE (in shares) at Dec. 31, 2021		92,170,480
Net income	386,636			386,636
Other comprehensive income (loss)	(2,044)				(2,044)
Common stock issued in connection with the issuance (forfeiture) of restricted stock awards, net		$ 22	(22)
Common stock issued in connection with the issuance (forfeiture) of restricted stock awards, net (in shares)		21,700
Common stock repurchase	(65,721)	$ (982)	(64,739)
Common stock repurchase (in shares)		(981,884)
Stock based compensation expense	8,457		8,457
Cash dividends declared	(142,922)			(142,922)
BALANCE at Sep. 30, 2022	6,611,642	$ 91,211	3,538,719	2,981,947	(235)
BALANCE (in shares) at Sep. 30, 2022		91,210,296
BALANCE at Jun. 30, 2022	6,521,827	$ 91,196	3,535,877	2,893,556	1,198
BALANCE (in shares) at Jun. 30, 2022		91,195,646
Net income	135,820			135,820
Other comprehensive income (loss)	(1,433)				(1,433)
Common stock issued in connection with the issuance (forfeiture) of restricted stock awards, net		$ 15	(15)
Common stock issued in connection with the issuance (forfeiture) of restricted stock awards, net (in shares)		14,650
Stock based compensation expense	2,857		2,857
Cash dividends declared	(47,429)			(47,429)
BALANCE at Sep. 30, 2022	6,611,642	$ 91,211	3,538,719	2,981,947	(235)
BALANCE (in shares) at Sep. 30, 2022		91,210,296
BALANCE at Dec. 31, 2022	6,699,374	$ 91,314	3,541,924	3,069,609	(3,473)
BALANCE (in shares) at Dec. 31, 2022		91,313,615
Net income	323,840			323,840
Other comprehensive income (loss)	1,543				1,543
Common stock issued in connection with the issuance (forfeiture) of restricted stock awards, net		$ 27	(27)
Common stock issued in connection with the issuance (forfeiture) of restricted stock awards, net (in shares)		27,200
Common stock issued in connection with the acquisition of First Bancshares of Texas, Inc	224,347	$ 3,583	220,764
Common stock issued in connection with the acquisition of First Bancshares of Texas, Inc, (in shares)		3,582,675
Common stock repurchase	(72,248)	$ (1,206)	(71,042)
Common stock repurchase (in shares)		(1,206,036)
Stock based compensation expense	9,056		9,056
Cash dividends declared	(153,235)			(153,235)
BALANCE at Sep. 30, 2023	7,032,677	$ 93,718	3,700,675	3,240,214	(1,930)
BALANCE (in shares) at Sep. 30, 2023		93,717,454
BALANCE at Jun. 30, 2023	6,968,116	$ 93,722	3,697,524	3,179,551	(2,681)
BALANCE (in shares) at Jun. 30, 2023		93,721,454
Net income	112,208			112,208
Other comprehensive income (loss)	751				751
Common stock issued in connection with the issuance (forfeiture) of restricted stock awards, net		$ (4)	4
Common stock issued in connection with the issuance (forfeiture) of restricted stock awards, net (in shares)		(4,000)
Stock based compensation expense	3,147		3,147
Cash dividends declared	(51,545)			(51,545)
BALANCE at Sep. 30, 2023	$ 7,032,677	$ 93,718	$ 3,700,675	$ 3,240,214	$ (1,930)
BALANCE (in shares) at Sep. 30, 2023		93,717,454

Consolidated Statements of Ch_2

Consolidated Statements of Changes in Shareholders' Equity (Unaudited) (Parenthetical) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Retained Earnings [Member]
Cash dividend declared, per share (in dollars per share)	$ 0.55	$ 0.52	$ 1.65	$ 1.56

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 323,840	$ 386,636
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and core deposit intangibles amortization	22,793	21,300
Provision for credit losses	18,540
Net amortization of premium on investments	21,412	34,254
Net gain on sale of other real estate and repossessed assets	(780)	(820)
Net gain on sale or write down of premises and equipment	(2,070)	(1,847)
Net accretion of discount on loans	(5,566)	(6,488)
Net amortization of premium on deposits	(450)	(252)
Net gain on sale of loans	(1,670)	(1,193)
Proceeds from sale of loans held for sale	68,827	50,903
Originations of loans held for sale	(77,242)	(45,307)
Stock based compensation expense	9,056	8,457
Decrease (increase) in accrued interest receivable and other assets	47,911	(57,322)
Increase in accrued interest payable and other liabilities	193,806	118,683
Net cash provided by operating activities	618,407	507,004
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from maturities and principal paydowns of held to maturity securities	1,308,839	1,710,143
Purchase of held to maturity securities	(3,028)	(3,756,166)
Proceeds from maturities and principal paydowns of available for sale securities	11,220,463	15,302,271
Purchase of available for sale securities	(11,026,566)	(15,280,674)
Originations of Warehouse Purchase Program loans	(9,877,760)	(15,919,159)
Proceeds from pay-offs of Warehouse Purchase Program loans	9,706,053	16,772,094
Net increase in loans held for investment	(818,194)	(747,296)
Purchase of bank premises and equipment	(29,517)	(34,250)
Proceeds from sale of bank premises, equipment and other real estate	7,170	6,699
Proceeds from insurance claims	11,427	2,603
Net cash used in the purchase of First Bancshares of Texas, Inc.	(24,365)
Net cash provided by (used in) investing activities	474,522	(1,943,735)
CASH FLOWS FROM FINANCING ACTIVITIES:
Net (decrease) increase in noninterest-bearing deposits	(1,325,801)	404,109
Net decrease in interest-bearing deposits	(1,472,467)	(1,875,524)
Net proceeds from other short-term borrowings	2,199,614	1,165,000
Net (decrease) increase in securities sold under repurchase agreements	(177,294)	6,205
Redemption of junior subordinated debentures	(3,158)
Repurchase of common stock	(72,248)	(65,721)
Payments of cash dividends	(153,235)	(142,922)
Net cash used in financing activities	(1,004,589)	(508,853)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	88,340	(1,945,584)
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	424,133	2,547,980
CASH AND CASH EQUIVALENTS, END OF PERIOD	512,473	602,396
NONCASH ACTIVITIES:
Acquisition of real estate through foreclosure of collateral	10,249	2,027
SUPPLEMENTAL INFORMATION:
Income taxes paid	93,675	95,302
Interest paid	$ 275,113	$ 36,311

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
Pay vs Performance Disclosure - USD ($) $ in Thousands	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Pay vs Performance Disclosure
Net Income (Loss)	$ 112,208	$ 135,820	$ 323,840	$ 386,636

Insider Trading Arrangements

Insider Trading Arrangements	9 Months Ended
Insider Trading Arrangements	Sep. 30, 2023
Trading Arrangements, by Individual
Title	director or officer
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Basis of Presentation

Basis of Presentation	9 Months Ended
Basis of Presentation	Sep. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	1. BASIS OF PRESENTATION The consolidated financial statements include the accounts of Prosperity Bancshares, Inc. ® (“Bancshares”) and its wholly-owned subsidiary, Prosperity Bank ® (the “Bank,” and together with Bancshares, the “Company”). All intercompany transactions and balances have been eliminated. The accompanying unaudited consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) for financial information and with the rules and regulations of the Securities and Exchange Commission. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. In the opinion of management, the statements reflect all adjustments necessary for a fair presentation of the financial position, results of operations and cash flows of the Company on a consolidated basis; and all such adjustments are of a normal recurring nature. These financial statements and the notes thereto should be read in conjunction with the Company’s Annual Report on Form 10-K for the year ended December 31, 2022. Operating results for the nine-month period ended September 30, 2023 are not necessarily indicative of the results that may be expected for the year ending December 31, 2023 or any other period.

Income Per Common Share

Income Per Common Share	9 Months Ended
Income Per Common Share	Sep. 30, 2023
Earnings Per Share [Abstract]
Income Per Common Share	2. INCOME PER COMMON SHARE The following table illustrates the computation of basic and diluted earnings per share: Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Amount Per Share Amount Amount Per Share Amount Amount Per Share Amount Amount Per Share Amount (Amounts in thousands, except per share data) Net income $ 112,208 $ 135,820 $ 323,840 $ 386,636 Basic: Weighted average shares outstanding 93,720 $ 1.20 91,209 $ 1.49 92,628 $ 3.50 91,710 $ 4.22 Diluted: Weighted average shares outstanding 93,720 $ 1.20 91,209 $ 1.49 92,628 $ 3.50 91,710 $ 4.22 There were no stock options outstanding at September 30, 2023 or exercisable during the three and nine months ended September 30, 2023 or 2022 that would have had an anti-dilutive effect on the above computation.

New Accounting Standards

New Accounting Standards	9 Months Ended
New Accounting Standards	Sep. 30, 2023
Accounting Standards Update and Change in Accounting Principle [Abstract]
New Accounting Standards	3. NEW ACCOUNTING STANDARDS Accounting Standards Updates (“ASU”) ASU 2022-02, Financial Instruments—Credit Losses (Topic 326): Troubled Debt Restructurings and Vintage Disclosures. The amendments in ASU 2022-02 eliminated the accounting guidance for troubled debt restructurings and enhanced disclosures for certain loan refinancing and restructurings to borrowers experiencing financial difficulty. This guidance was applied on a prospective basis. Additionally, ASU 2022-02 requires entities to disclose current-period gross charge-offs by year of origination. ASU 2022-02 became effective for the Company on January 1, 2023 and did not have a significant impact on the Company’s financial statements. ASU 2020-04, Reference Rate Reform: Facilitation of the Effects of Reference Rate Reform on Financial Reporting – ASC Topic 848. ASU 2020-04 became effective for the Company on January 1, 2022 and provides optional expedients and exceptions for applying GAAP to loan and lease agreements, derivative contracts, and other transactions affected by the anticipated transition away from the London Inter-Bank Offered Rate (“LIBOR”) toward new interest rate benchmarks. ASU 2020-04 was effective upon issuance. In addition, the Financial Accounting Standards Board (“FASB”) issued ASU 2022-06 - Reference Rate Reform (Topic 848): Deferral of the Sunset Date of Topic 848 , which extends the period of time preparers can utilize the reference rate reform relief guidance provided by ASU 2020-04 from December 31, 2022 to December 31, 2024. ASU 2022-06 was effective upon issuance and did not change the core principles in ASU 2020-04. Prior to the end of 2021, the Company began transitioning away from LIBOR to the Secured Overnight Financing Rate (“SOFR”) or other alternative variable rate indexes for its interest-rate swaps and loans historically using LIBOR as an index. As of September 30, 2023, the Company's interest rate swaps and loan portfolio used SOFR as the index rate . As of December 31, 2022, LIBOR was used as an index rate for approximately 88.2 % of the Company’s interest-rate swaps and approximately 1.5 % of the Company’s loan portfolio. The adoption of ASU 2020-04 did not have a significant impact on the Company’s financial statements.

Securities

Securities	9 Months Ended
Securities	Sep. 30, 2023
Investments, Debt and Equity Securities [Abstract]
Securities	4. SECURITIES The amortized cost and fair value of investment securities were as follows: September 30, 2023 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (Dollars in thousands) Available for Sale Corporate debt securities $ 20,698 $ 1,652 $ ( 865 ) $ 21,485 Collateralized mortgage obligations 329,465 1,018 ( 2,959 ) 327,524 Mortgage-backed securities 98,445 22 ( 1,311 ) 97,156 Total $ 448,608 $ 2,692 $ ( 5,135 ) $ 446,165 Held to Maturity U.S. Treasury securities and obligations of U.S. Government agencies $ 7,571 $ — $ ( 208 ) $ 7,363 States and political subdivisions 113,786 228 ( 4,723 ) 109,291 Corporate debt securities 12,000 — ( 4,560 ) 7,440 Collateralized mortgage obligations 271,570 — ( 29,507 ) 242,063 Mortgage-backed securities 12,341,650 64 ( 1,873,652 ) 10,468,062 Total $ 12,746,577 $ 292 $ ( 1,912,650 ) $ 10,834,219 December 31, 2022 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (Dollars in thousands) Available for Sale Collateralized mortgage obligations $ 359,251 $ 1,190 $ ( 3,039 ) $ 357,402 Mortgage-backed securities 101,647 93 ( 2,640 ) 99,100 Total $ 460,898 $ 1,283 $ ( 5,679 ) $ 456,502 Held to Maturity States and political subdivisions $ 122,361 $ 868 $ ( 3,255 ) $ 119,974 Corporate debt securities 12,000 — ( 2,520 ) 9,480 Collateralized mortgage obligations 271,727 377 ( 22,922 ) 249,182 Mortgage-backed securities 13,613,415 2,575 ( 1,607,501 ) 12,008,489 Total $ 14,019,503 $ 3,820 $ ( 1,636,198 ) $ 12,387,125 The investment securities portfolio is measured for expected credit losses by segregating the portfolio into two general segments and applying the appropriate expected credit losses methodology. Investment securities classified as available for sale or held to maturity are evaluated for expected credit losses under FASB ASC 326 , “Financial Instruments – Credit Losses.” Available for sale securities . For available for sale securities in an unrealized loss position, the amount of the expected credit losses recognized in earnings depends on whether an entity intends to sell the security or more likely than not will be required to sell the security before recovery of its amortized cost basis less any current-period credit loss. If an entity intends to sell or more likely than not will be required to sell the security before recovery of its amortized cost basis less any current-period credit loss, the expected credit losses will be recognized in earnings equal to the entire difference between the investment’s amortized cost basis and its fair value at the balance sheet date. If an entity does not intend to sell the security and it is not more likely than not that the entity will be required to sell the security before recovery of its amortized cost basis less any current-period loss, the expected credit losses will be separated into the amount representing the credit-related portion of the impairment loss (“credit loss”) and the noncredit portion of the impairment loss (“noncredit portion”). The amount of the total expected credit losses related to the credit loss is determined based on the difference between the present value of cash flows expected to be collected and the amortized cost basis and such difference is recognized in earnings. The amount of the total expected credit losses related to the noncredit portion is recognized in other comprehensive income, net of applicable taxes. The previous amortized cost basis less the expected credit losses recognized in earnings will become the new amortized cost basis of the investment. As of September 30, 2023, management does not have the intent to sell any of the securities classified as available for sale before a recovery of cost. In addition, management believes it is more likely than not that the Company will not be required to sell any of its investment securities before a recovery of cost. The unrealized losses are largely due to changes in market interest rates and spread relationships since 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. Management does not believe any of the securities are impaired due to reasons of credit quality. Accordingly, as of September 30, 2023, management believes that there is no potential for credit losses on available for sale securities. Held to maturity securities . The Company’s held to maturity investments include mortgage-related bonds issued by either the Government National Mortgage Corporation (“Ginnie Mae”), Federal National Mortgage Association (“Fannie Mae”) or Federal Home Loan Mortgage Corporation (“Freddie Mac”). Ginnie Mae issued securities are explicitly guaranteed by the U.S. government, while Fannie Mae and Freddie Mac issued securities are fully guaranteed by those respective United States government-sponsored agencies and conditionally guaranteed by the full faith and credit of the United States. The Company’s held to maturity securities also include taxable and tax-exempt municipal securities issued primarily by school districts, utility districts and municipalities located in Texas. The Company’s investment in municipal securities is exposed to credit risk. The securities are highly rated by major rating agencies and regularly reviewed by management. A significant portion are guaranteed or insured by either the Texas Permanent School Fund, Assured Guaranty or Build America Mutual. As of September 30, 2023, the Company’s municipal securities represent 0.9 % of the securities portfolio. Management has the ability and intent to hold the securities classified as held to maturity until they mature, at which time the Company will receive full value for the securities. Accordingly, as of September 30, 2023 , management believes that there is no potential for material credit losses on held to maturity securities. Securities with unrealized losses, segregated by length of time, that have been in a continuous loss position were as follows: September 30, 2023 Less than 12 Months 12 Months or More Total Estimated Fair Value Unrealized Losses Estimated Fair Value Unrealized Losses Estimated Fair Value Unrealized Losses (Dollars in thousands) Available for Sale Corporate debt securities $ 7,173 $ ( 865 ) $ — $ — $ 7,173 $ ( 865 ) Collateralized mortgage obligations 44,012 ( 373 ) 116,982 ( 2,586 ) 160,994 ( 2,959 ) Mortgage-backed securities 2,698 ( 55 ) 92,530 ( 1,256 ) 95,228 ( 1,311 ) Total $ 53,883 $ ( 1,293 ) $ 209,512 $ ( 3,842 ) $ 263,395 $ ( 5,135 ) Held to Maturity U.S. Treasury securities and obligations of U.S. Government agencies $ 7,363 $ ( 208 ) $ — $ — $ 7,363 $ ( 208 ) States and political subdivisions 50,902 ( 997 ) 39,698 ( 3,726 ) 90,600 ( 4,723 ) Corporate debt securities — — 7,440 ( 4,560 ) 7,440 ( 4,560 ) Collateralized mortgage obligations 51,009 ( 1,187 ) 191,012 ( 28,320 ) 242,021 ( 29,507 ) Mortgage-backed securities 227,436 ( 7,382 ) 10,235,113 ( 1,866,270 ) 10,462,549 ( 1,873,652 ) Total $ 336,710 $ ( 9,774 ) $ 10,473,263 $ ( 1,902,876 ) $ 10,809,973 $ ( 1,912,650 ) December 31, 2022 Less than 12 Months 12 Months or More Total Estimated Fair Value Unrealized Losses Estimated Fair Value Unrealized Losses Estimated Fair Value Unrealized Losses (Dollars in thousands) Available for Sale Collateralized mortgage obligations $ 61,559 $ ( 3,012 ) $ 99,179 $ ( 27 ) $ 160,738 $ ( 3,039 ) Mortgage-backed securities 95,212 ( 2,627 ) 291 ( 13 ) 95,503 ( 2,640 ) Total $ 156,771 $ ( 5,639 ) $ 99,470 $ ( 40 ) $ 256,241 $ ( 5,679 ) Held to Maturity States and political subdivisions $ 49,782 $ ( 885 ) $ 16,298 $ ( 2,370 ) $ 66,080 $ ( 3,255 ) Corporate debt securities 9,480 ( 2,520 ) — — 9,480 ( 2,520 ) Collateralized mortgage obligations 214,538 ( 22,557 ) 4,358 ( 365 ) 218,896 ( 22,922 ) Mortgage-backed securities 5,276,315 ( 416,053 ) 6,585,470 ( 1,191,448 ) 11,861,785 ( 1,607,501 ) Total $ 5,550,115 $ ( 442,015 ) $ 6,606,126 $ ( 1,194,183 ) $ 12,156,241 $ ( 1,636,198 ) At September 30, 2023 and December 31, 2022 , there were 947 securities and 174 securities, respectively, in an unrealized loss position for 12 months or more. The table below summarizes the amortized cost and fair value of investment securities at September 30, 2023, by contractual maturity. Actual maturities will differ from contractual maturities because borrowers may have the right to call or prepay obligations at any time with or without call or prepayment penalties. Held to Maturity Available for Sale Amortized Cost Fair Value Amortized Cost Fair Value (Dollars in thousands) Due in one year or less $ 25,590 $ 25,761 $ — $ — Due after one year through five years 49,927 48,679 2,550 2,865 Due after five years through ten years 45,822 39,137 18,148 18,620 Due after ten years 12,018 10,517 — — Subtotal 133,357 124,094 20,698 21,485 Mortgage-backed securities and collateralized mortgage obligations 12,613,220 10,710,125 427,910 424,680 Total $ 12,746,577 $ 10,834,219 $ 448,608 $ 446,165 The Company recorded no gain or loss on the sale of securities for the three and nine months ended September 30, 2023 and 2022. As of September 30, 2023, the Company did not own any non-agency collateralized mortgage obligations. At September 30, 2023 and December 31, 2022 , the Company did not own securities of any one issuer (other than the U.S. government and its agencies) for which aggregate adjusted cost exceeded 10 % of the consolidated shareholders’ equity at such respective dates. Securities with an amortized cost of $ 10.33 billion and $ 7.87 billion and a fair value of $ 8.75 billion and $ 6.90 billion at September 30, 2023 and December 31, 2022 , respectively, were pledged to collateralize public deposits and for other purposes required or permitted by law.

Loans and Allowance for Credit

Loans and Allowance for Credit Losses	9 Months Ended
Loans and Allowance for Credit Losses	Sep. 30, 2023
Receivables [Abstract]
Loans and Allowance for Credit Losses	5. LOANS AND ALLOWANCE FOR CREDIT LOSSES The loan portfolio consists of various types of loans and is categorized by major type as follows: September 30, 2023 December 31, 2022 (Dollars in thousands) Residential mortgage loans held for sale $ 10,187 $ 554 Commercial and industrial 2,603,028 2,594,742 Real estate: Construction, land development and other land loans 3,200,479 2,805,438 1-4 family residential (includes home equity) 7,991,904 6,740,670 Commercial real estate (includes multi-family residential) 5,606,837 4,986,211 Farmland 595,182 518,095 Agriculture 206,751 169,938 Consumer and other 306,018 283,559 Total loans held for investment, excluding Warehouse Purchase Program 20,510,199 18,098,653 Warehouse Purchase Program 912,327 740,620 Total loans, including Warehouse Purchase Program $ 21,432,713 $ 18,839,827 Concentrations of Credit. Most of the Company’s lending activity occurs within the states of Texas and Oklahoma. Commercial real estate loans, 1-4 family residential loans and construction, land development and other land loans make up 81.9 % and 80.3 % of the Company’s total loan portfolio, excluding Warehouse Purchase Program loans, at September 30, 2023 and December 31, 2022, respectively. As of September 30, 2023 and December 31, 2022 , excluding Warehouse Purchase Program loans, there were no concentrations of loans related to any single industry in excess of 10 % of total loans. Related Party Loans. As of September 30, 2023 and December 31, 2022 , loans outstanding to directors, officers and their affiliates totaled $ 295 thousand and $ 547 thousand, respectively. All transactions between the Company and such related parties are conducted in the ordinary course of business and made on the same terms and conditions as similar transactions with unaffiliated persons. An analysis of activity with respect to these related party loans is as follows: As of and for the As of and for the 31, 2022 (Dollars in thousands) Beginning balance on January 1 $ 547 $ 6,524 New loans 57 54 Repayments ( 309 ) ( 6,031 ) Ending balance $ 295 $ 547 Nonperforming Assets and Nonaccrual and Past Due Loans. The Company has several procedures in place to assist it in maintaining the overall quality of its loan portfolio. The Company has established underwriting guidelines to be followed by its officers, including requiring appraisals on loans collateralized by real estate. The Company also monitors its delinquency levels for any negative or adverse trends. Nevertheless, the Company’s loan portfolio could become subject to increasing pressures from deteriorating borrower credit due to general economic conditions. The Company generally places a loan on nonaccrual status and ceases accruing interest when the payment of principal or interest is delinquent for 90 days, or earlier in some cases; unless the loan is in the process of collection and the underlying collateral fully supports the carrying value of the loan. 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. With respect to potential problem loans, an evaluation of the borrower’s overall financial condition is made to determine the need, if any, for possible write-downs or appropriate additions to the allowance for credit losses. An aging analysis of past due loans, segregated by category of loan, is presented below: September 30, 2023 Loans Past Due and Still Accruing 30-89 Days 90 or More Days Total Past Due Loans Nonaccrual Loans Current Loans Total Loans (Dollars in thousands) Construction, land development and other land loans $ 9,238 $ — $ 9,238 $ 7,746 $ 3,183,495 $ 3,200,479 Warehouse Purchase Program loans — — — — 912,327 912,327 Agriculture and agriculture real estate (includes farmland) 3,755 — 3,755 1,511 796,667 801,933 1-4 family (includes home equity) (1) 34,229 — 34,229 23,439 7,944,423 8,002,091 Commercial real estate (includes multi-family residential) 5,974 — 5,974 5,228 5,595,635 5,606,837 Commercial and industrial 51,314 397 51,711 21,787 2,529,530 2,603,028 Consumer and other 493 — 493 18 305,507 306,018 Total $ 105,003 $ 397 $ 105,400 $ 59,729 $ 21,267,584 $ 21,432,713 December 31, 2022 Loans Past Due and Still Accruing 30-89 Days 90 or More Days Total Past Due Loans Nonaccrual Loans Current Loans Total Loans (Dollars in thousands) Construction, land development and other land loans $ 9,976 $ 4,442 $ 14,418 $ 318 $ 2,790,702 $ 2,805,438 Warehouse Purchase Program loans — — — — 740,620 740,620 Agriculture and agriculture real estate (includes farmland) 1,751 — 1,751 421 685,861 688,033 1-4 family (includes home equity) (1) 25,880 7 25,887 14,762 6,700,575 6,741,224 Commercial real estate (includes multi-family residential) 3,176 — 3,176 1,649 4,981,386 4,986,211 Commercial and industrial 10,575 1,468 12,043 2,453 2,580,246 2,594,742 Consumer and other 378 — 378 11 283,170 283,559 Total $ 51,736 $ 5,917 $ 57,653 $ 19,614 $ 18,762,560 $ 18,839,827 (1) Includes $ 10.2 million and $ 554 thousand of residential mortgage loans held for sale at September 30, 2023 and December 31, 2022 , respectively. The following table presents information regarding nonperforming assets as of the dates indicated: September 30, 2023 December 31, 2022 (Dollars in thousands) Nonaccrual loans (1) (3) $ 59,729 $ 19,614 (2) Accruing loans 90 or more days past due 397 5,917 Total nonperforming loans 60,126 25,531 Repossessed assets 35 — Other real estate 9,320 1,963 Total nonperforming assets $ 69,481 $ 27,494 Nonperforming assets to total loans and other real estate 0.32 % 0.15 % Nonperforming assets to total loans, excluding Warehouse Purchase Program loans, and other real estate 0.34 % 0.15 % Nonaccrual loans to total loans 0.28 % 0.10 % Nonaccrual loans to total loans, excluding Warehouse Purchase Program loans 0.29 % 0.11 % (1) ASU 2022-02 became effective for the Company on January 1, 2023. (2) Includes troubled debt restructurings of $ 4.6 million as of December 31, 2022 . (3) There were no nonperforming Warehouse Purchase Program loans or Warehouse Purchase Program lines of credit for the periods presented. The Company had $ 69.5 million in nonperforming assets at September 30, 2023 compared with $ 27.5 million at December 31, 2022. This increase was primarily due to the merger of First Bancshares of Texas, Inc. (“First Bancshares”) into Bancshares and the subsequent merger of its wholly owned subsidiary FirstCapital Bank of Texas, N.A. (“FirstCapital Bank”) into the Bank (collectively, the “Merger”). Nonperforming assets were 0.32 % of total loans and other real estate at September 30, 2023 and 0.15 % of total loans and other real estate at December 31, 2022 . The Company had $ 59.7 million in nonaccrual loans at September 30, 2023 compared with $ 19.6 million at December 31, 2022. Acquired Loans. Acquired loans were preliminarily recorded at fair value based on a discounted cash flow valuation methodology that considers, among other things, interest rates, projected default rates, loss given default, and recovery rates. Projected default rates, loss given default, and recovery rates for purchased credit deteriorated (“PCD”) loans primarily impact the related allowance, as opposed to the fair value mark. During the valuation process, the Company identified PCD and Non-PCD loans in the acquired loan portfolios. Loans acquired with evidence of credit quality deterioration since origination as of the acquisition date were accounted for as PCD. PCD loan identification considers the following factors: payment history and past due status, debt service coverage, loan grading, collateral values and other factors that may indicate deterioration of credit quality as of the acquisition date when compared to the origination date. Non-PCD loan identification considers the following factors: account types, remaining terms, annual interest rates or coupons, current market rates, interest types, past delinquencies, timing of principal and interest payments, loan to value ratios, loss exposures and remaining balances. Accretion of purchased discounts on PCD and Non-PCD loans will be recognized based on payment structure and the contractual maturity of individual loans. PCD Loans. The recorded investment in PCD loans included in the consolidated balance sheet and the related outstanding balance as of the dates indicated are presented in the table below. The outstanding balance represents the total amount owed as of September 30, 2023 and December 31, 2022. September 30, 2023 December 31, 2022 (Dollars in thousands) PCD loans: Outstanding balance $ 620,324 $ 63,383 Discount ( 9,343 ) ( 3,361 ) Recorded investment $ 610,981 $ 60,022 Changes in the accretable yield for acquired PCD loans for the three and nine months ended September 30, 2023 and 2022 were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 (Dollars in thousands) Balance at beginning of period $ 10,110 $ 3,993 $ 3,361 $ 4,838 Additions — — 8,336 — Adjustments — — ( 70 ) — Accretion ( 767 ) ( 322 ) ( 2,284 ) ( 1,167 ) Balance at September 30, $ 9,343 $ 3,671 $ 9,343 $ 3,671 Income recognition on PCD loans is subject to the timing and amount of future cash flows. PCD loans for which the Company is accruing interest income are not considered nonperforming or impaired. The PCD discount reflected above as of September 30, 2023, represents the amount of discount available to be recognized as income. Non-PCD Loans. The recorded investment in Non-PCD loans included in the consolidated balance sheet and the related outstanding balance as of the dates indicated are presented in the table below. The outstanding balance represents the total amount owed as of September 30, 2023 and December 31, 2022. September 30, 2023 December 31, 2022 (Dollars in thousands) Non-PCD loans: Outstanding balance $ 1,959,822 $ 1,319,507 Discount ( 21,543 ) ( 2,233 ) Recorded investment $ 1,938,279 $ 1,317,274 Changes in the discount accretion for Non-PCD loans for the three and nine months ended September 30, 2023 and 2022 were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 (Dollars in thousands) Balance at beginning of period $ 23,052 $ 3,734 $ 2,233 $ 8,143 Addition — — 22,593 — Accretion charge-offs ( 1 ) 14 ( 1 ) 14 Accretion ( 1,508 ) ( 912 ) ( 3,282 ) ( 5,321 ) Balance at September 30, $ 21,543 $ 2,836 $ 21,543 $ 2,836 Credit Quality Indicators. As part of the ongoing monitoring of the credit quality of the Company’s loan portfolio and methodology for calculating the allowance for credit losses, management assigns and tracks loan grades to be used as credit quality indicators. The following is a general description of the loan grades used: Grade 1— Credits in this category have risk potential that is virtually nonexistent. These loans may be secured by insured certificates of deposit, insured savings accounts, U.S. Government securities and highly rated municipal bonds. Grade 2— Credits in this category are of the highest quality. These borrowers represent top rated companies and individuals with unquestionable financial standing with excellent global cash flow coverage, net worth, liquidity and collateral coverage. Grade 3— Credits in this category are not immune from risk but are well protected by the collateral and paying capacity of the borrower. These loans may exhibit a minor unfavorable credit factor, but the overall credit is sufficiently strong to minimize the possibility of loss. Grade 4— Credits in this category are considered to be of acceptable credit quality with moderately greater risk than Grade 3 and receiving closer monitoring. Loans in this category have sources of repayment that remain sufficient to preclude a larger than normal probability of default and secondary sources are likewise currently of sufficient quantity, quality, and liquidity to protect the Company against loss of principal and interest. These borrowers have specific risk factors, but the overall strength of the credit is acceptable based on other mitigating credit and/or collateral factors and can repay the debt in the normal course of business. Grade 5— Credits in this category constitute an undue and unwarranted credit risk; however, the factors do not rise to a level of substandard. These credits have potential weaknesses and/or declining trends that, if not corrected, could expose the Company to risk at a future date. These loans are monitored on the Company’s internally-generated watch list and evaluated on a quarterly basis. Grade 6— Credits in this category are considered “substandard” but “non-impaired” loans in accordance with regulatory guidelines. Loans in this category have well-defined weakness that, if not corrected, could make default of principal and interest possible. Loans in this category are still accruing interest and may be dependent upon secondary sources of repayment and/or collateral liquidation. Grade 7— Credits in this category are deemed “substandard” and “impaired” pursuant to regulatory guidelines. As such, the Company has determined that it is probable that less than 100% of the contractual principal and interest will be collected. These loans are individually evaluated for a specific reserve and will typically have the accrual of interest stopped. Grade 8— Credits in this category include “doubtful” loans in accordance with regulatory guidance. Such loans are no longer accruing interest and factors indicate a loss is imminent. These loans are also deemed “impaired.” While a specific reserve may be in place while the loan and collateral are being evaluated, these loans are typically charged down to an amount the Company estimates is collectible. Grade 9— Credits in this category are deemed a “loss” in accordance with regulatory guidelines and have been charged off or charged down. The Company may continue collection efforts and may have partial recovery in the future. The following tables present loans by risk grade, by category of loan and year of origination/renewal at September 30, 2023. Term Loans Amortized Cost Basis by Origination Year 2023 2022 2021 2020 2019 Prior Revolving Loans Revolving Loans Converted to Term Loans Total (Dollars in thousands) Construction, Land Development and Other Land Loans Grade 1 $ — $ — $ — $ — $ — $ — $ — $ — $ — Grade 2 1,136 178 — — — 70 — — 1,384 Grade 3 413,440 1,103,554 495,407 210,484 21,398 171,312 201,230 7,015 2,623,840 Grade 4 40,692 98,550 94,091 35,723 2,396 11,667 5,467 — 288,586 Grade 5 — — 4,399 — 18,678 629 915 — 24,621 Grade 6 — — 6,217 191 230 1,185 — — 7,823 Grade 7 — 928 1,647 3,318 — 1,587 266 — 7,746 Grade 8 — — — — — — — — — Grade 9 — — — — — — — — — PCD Loans 47,107 129,665 30,405 7,458 3,553 6,267 22,024 — 246,479 Total $ 502,375 $ 1,332,875 $ 632,166 $ 257,174 $ 46,255 $ 192,717 $ 229,902 $ 7,015 $ 3,200,479 Current-period gross write-offs $ — $ 77 $ — $ — $ — $ — $ — $ — $ 77 Agriculture and Agriculture Real Estate (includes Farmland) Grade 1 $ 1,002 $ 1,318 $ 323 $ 393 $ 19 $ 391 $ 8,770 $ — $ 12,216 Grade 2 — 75 104 — — 1,073 52 — 1,304 Grade 3 128,543 193,029 87,352 47,367 37,641 101,562 82,906 95 678,495 Grade 4 9,971 16,900 19,557 5,395 451 7,955 22,387 1,008 83,624 Grade 5 70 794 286 — 441 1,466 — — 3,057 Grade 6 — — 116 — — 478 — — 594 Grade 7 — — 1,334 — 15 162 — — 1,511 Grade 8 — — — — — — — — — Grade 9 — — — — — — — — — PCD Loans 216 2,333 1,769 3,793 1,214 3,604 2,914 5,289 21,132 Total $ 139,802 $ 214,449 $ 110,841 $ 56,948 $ 39,781 $ 116,691 $ 117,029 $ 6,392 $ 801,933 Current-period gross write-offs $ — $ — $ — $ 113 $ — $ — $ — $ — $ 113 1-4 Family (includes Home Equity) (1) Grade 1 $ 76 $ 158 $ — $ 110 $ — $ — $ — $ — $ 344 Grade 2 738 1,403 158 249 32 3,162 119 — 5,861 Grade 3 1,066,962 2,011,417 2,165,072 1,065,471 436,951 991,862 93,437 1,463 7,832,635 Grade 4 11,650 20,065 24,273 5,945 13,627 51,076 3,191 — 129,827 Grade 5 — 58 — 122 — 2,496 — — 2,676 Grade 6 — — 224 15 244 1,582 — — 2,065 Grade 7 244 3,984 5,244 3,528 1,904 8,459 76 — 23,439 Grade 8 — — — — — — — — — Grade 9 — — — — — — — — — PCD Loans 175 1,523 515 439 640 1,952 — — 5,244 Total $ 1,079,845 $ 2,038,608 $ 2,195,486 $ 1,075,879 $ 453,398 $ 1,060,589 $ 96,823 $ 1,463 $ 8,002,091 Current-period gross write-offs $ — $ 20 $ 50 $ 26 $ — $ 25 $ — $ — $ 121 Term Loans Amortized Cost Basis by Origination Year 2023 2022 2021 2020 2019 Prior Revolving Loans Revolving Loans Converted to Term Loans Total (Dollars in thousands) Commercial Real Estate (includes Multi-Family Residential) Grade 1 $ — $ — $ — $ — $ — $ — $ 48 $ — $ 48 Grade 2 — 1,439 — 483 — 2,467 — — 4,389 Grade 3 377,792 940,534 685,352 487,881 318,912 1,084,441 85,263 240 3,980,415 Grade 4 32,814 150,750 175,683 179,686 104,998 546,811 14,942 1,127 1,206,811 Grade 5 — — — — 14,988 45,636 1,555 — 62,179 Grade 6 — 934 1,548 11,946 15,938 89,267 — — 119,633 Grade 7 — 827 365 — 3,473 563 — — 5,228 Grade 8 — — — — — — — — — Grade 9 — — — — — — — — — PCD Loans 17,500 47,252 45,997 40,404 8,078 68,523 380 — 228,134 Total $ 428,106 $ 1,141,736 $ 908,945 $ 720,400 $ 466,387 $ 1,837,708 $ 102,188 $ 1,367 $ 5,606,837 Current-period gross write-offs $ — $ 14,975 $ — $ — $ — $ 584 $ — $ — $ 15,559 Commercial and Industrial Grade 1 $ 13,792 $ 11,407 $ 9,334 $ 3,841 $ 1,267 $ 5,054 $ 33,533 $ 43 $ 78,271 Grade 2 708 8,029 253 217 — 3,842 2,438 — 15,487 Grade 3 200,642 281,096 177,474 68,507 43,171 152,826 994,460 684 1,918,860 Grade 4 68,384 20,313 15,982 11,176 22,026 88,864 184,842 478 412,065 Grade 5 3,182 22,373 2,263 1,060 408 470 1,255 6,475 37,486 Grade 6 42 489 275 1,398 1,080 1,111 4,671 111 9,177 Grade 7 4,712 15,360 186 — 77 693 759 — 21,787 Grade 8 — — — — — — — — — Grade 9 — — — — — — — — — PCD Loans 6,410 23,067 11,847 4,755 5,658 1,156 56,805 197 109,895 Total $ 297,872 $ 382,134 $ 217,614 $ 90,954 $ 73,687 $ 254,016 $ 1,278,763 $ 7,988 $ 2,603,028 Current-period gross write-offs $ 10 $ 622 $ 145 $ 45 $ — $ 506 $ 1,875 $ — $ 3,203 Consumer and Other Grade 1 $ 11,930 $ 7,329 $ 3,463 $ 2,396 $ 1,314 $ 4,686 $ 1,873 $ — $ 32,991 Grade 2 12,584 14,202 — — — 2,009 7 — 28,802 Grade 3 61,873 43,988 28,130 28,237 11,606 11,571 49,034 92 234,531 Grade 4 1,926 290 1,191 1,068 1,301 572 3,231 — 9,579 Grade 5 — — — — — — — — — Grade 6 — — — — — — — — — Grade 7 — — — 15 3 — — — 18 Grade 8 — — — — — — — — — Grade 9 — — — — — — — — — PCD Loans — — 41 10 23 — 23 — 97 Total $ 88,313 $ 65,809 $ 32,825 $ 31,726 $ 14,247 $ 18,838 $ 54,168 $ 92 $ 306,018 Current-period gross write-offs $ 3,866 $ 71 $ 4 $ 27 $ 5 $ 20 $ 62 $ 11 $ 4,066 Term Loans Amortized Cost Basis by Origination Year 2023 2022 2021 2020 2019 Prior Revolving Loans Revolving Loans Converted to Term Loans Total (Dollars in thousands) Warehouse Purchase Program Grade 1 $ — $ — $ — $ — $ — $ — $ — $ — $ — Grade 2 — — — — — — — — — Grade 3 912,327 — — — — — — — 912,327 Grade 4 — — — — — — — — — Grade 5 — — — — — — — — — Grade 6 — — — — — — — — — Grade 7 — — — — — — — — — Grade 8 — — — — — — — — — Grade 9 — — — — — — — — — PCD Loans — — — — — — — — — Total $ 912,327 $ — $ — $ — $ — $ — $ — $ — $ 912,327 Current-period gross write-offs $ — $ — $ — $ — $ — $ — $ — $ — $ — Total Grade 1 $ 26,800 $ 20,212 $ 13,120 $ 6,740 $ 2,600 $ 10,131 $ 44,224 $ 43 $ 123,870 Grade 2 15,166 25,326 515 949 32 12,623 2,616 — 57,227 Grade 3 3,161,579 4,573,618 3,638,787 1,907,947 869,679 2,513,574 1,506,330 9,589 18,181,103 Grade 4 165,437 306,868 330,777 238,993 144,799 706,945 234,060 2,613 2,130,492 Grade 5 3,252 23,225 6,948 1,182 34,515 50,697 3,725 6,475 130,019 Grade 6 42 1,423 8,380 13,550 17,492 93,623 4,671 111 139,292 Grade 7 4,956 21,099 8,776 6,861 5,472 11,464 1,101 — 59,729 Grade 8 — — — — — — — — — Grade 9 — — — — — — — — — PCD Loans 71,408 203,840 90,574 56,859 19,166 81,502 82,146 5,486 610,981 Total $ 3,448,640 $ 5,175,611 $ 4,097,877 $ 2,233,081 $ 1,093,755 $ 3,480,559 $ 1,878,873 $ 24,317 $ 21,432,713 Current-period gross write-offs $ 3,876 $ 15,765 $ 199 $ 211 $ 5 $ 1,135 $ 1,937 $ 11 $ 23,139 (1) Includes $ 10.2 million of residential mortgage loans held for sale at September 30, 2023 . Allowance for Credit Losses on Loans. The allowance for credit losses is adjusted through charges to earnings in the form of a provision for credit losses. Management has established an allowance for credit losses which it believes is adequate as of September 30, 2023 for estimated losses in the Company’s loan portfolio. The amount of the allowance for credit losses on loans is affected by the following: (1) charge-offs of loans that occur when loans are deemed uncollectible and decrease the allowance, (2) recoveries on loans previously charged off that increase the allowance, (3) provisions for credit losses charged to earnings that increase the allowance, and (4) provision releases returned to earnings that decrease the allowance. Based on an evaluation of the loan portfolio and consideration of the factors listed below, management presents a quarterly review of the allowance for credit losses to the Bank’s Board of Directors, indicating any change in the allowance since the last review and any recommendations as to adjustments in the allowance. Although management believes it uses the best information available to make determinations with respect to the allowance for credit losses, future adjustments may be necessary if economic conditions or borrower performance differ from the assumptions used in making the initial determinations. The Company’s allowance for credit losses on loans consists of two components: (1) a specific valuation allowance based on expected losses on specifically identified loans and (2) a general valuation allowance based on historical lifetime loan loss experience, current economic conditions, reasonable and supportable forecasted economic conditions and other qualitative risk factors both internal and external to the Company. In setting the specific valuation allowance, the Company follows a loan review program to evaluate the credit risk in the total loan portfolio and assigns risk grades to each loan. Through this loan review process, the Company maintains an internal list of impaired loans, which along with the delinquency list of loans, helps management assess the overall quality of the loan portfolio and the adequacy of the allowance for credit losses. All loans that have been identified as impaired are reviewed on a quarterly basis in order to determine whether a specific reserve is required. For certain impaired loans, the Company allocates a specific loan loss reserve primarily based on the value of the collateral securing the impaired loan in accordance with ASC Topic 326-20, “ Financial Instruments – Credit Losses. ” The specific reserves are determined on an individual loan basis. Loans for which specific reserves are provided are excluded from the general valuation allowance described below. In connection with this review of the loan portfolio, the Company considers risk elements attributable to particular loan types or categories in assessing the quality of individual loans. Some of the risk elements include: • for 1-4 family residential mortgage loans, the borrower’s ability to repay the loan, including a consideration of the debt to income ratio and employment and income stability, the loan to value ratio, and the age, condition and marketability of collateral; • for commercial real estate loans and multifamily residential loans, the debt service coverage ratio (income from the property in excess of operating expenses compared to loan payment requirements), operating results of the owner in the case of owner-occupied properties, the loan to value ratio, the age and condition of the collateral and the volatility of income, property value and future operating results typical of properties of that type; • for construction, land development and other land loans, the perceived feasibility of the project including the ability to sell developed lots or improvements constructed for resale or the ability to lease property constructed for lease, the quality and nature of contracts for presale or prelease, if any, experience and ability of the developer and loan to value ratio; • for commercial and industrial loans, the operating results of the commercial, industrial or professional enterprise, the borrower’s business, professional and financial ability and expertise, the specific risks and volatility of income and operating results typical for businesses in that category and the value, nature and marketability of collateral; • for the Warehouse Purchase Program, the capitalization and liquidity of the mortgage banking client, the operating experience, the client’s satisfactory underwriting of purchased loans and the consistent timeliness by the client of loan resale to investors; • for agriculture real estate loans, the experience and financial capability of the borrower, projected debt service coverage of the operations of the borrower and loan to value ratio; and • for non-real estate agriculture loans, the operating results, experience and financial capability of the borrower, historical and expected market conditions and the value, nature and marketability of collateral. In addition, for each category, the Company considers secondary sources of income and the financial strength and credit history of the borrower and any guarantors. In determining the amount of the general valuation allowance, management considers factors such as historical lifetime loan loss experience, concentration risk of specific loan types, the volume, growth and composition of the Company’s loan portfolio, current economic conditions and reasonable and supportable forecasted economic conditions that may affect borrower ability to pay and the value of collateral, the evaluation of the Company’s loan portfolio through its internal loan review process, other qualitative risk factors both internal and external to the Company and other relevant factors in accordance with ASC Topic 326, “ Financial Instruments – Credit Losses.” Historical lifetime loan loss experience is determined by utilizing an open-pool (“cumulative loss rate”) methodology. Adjustments to the historical lifetime loan loss experience are made for differences in current loan pool risk characteristics such as portfolio concentrations, delinquency, non-accrual, and watch list levels, as well as changes in current and forecasted economic conditions such as unemployment rates, property and collateral values, and other indices relating to economic activity. The utilization of reasonable and supportable forecasts includes an immediate reversion to lifetime historical loss rates. Based on a review of these factors for each loan type, the Company applies an estimated percentage to the outstanding balance of each loan type, excluding any loan that has a specific reserve. Allocation of a portion of the allowance to one category of loans does not preclude its availability to absorb losses in other categories. The following table details activity in the allowance for credit losses on loans by category of loan for the three and nine months ended September 30, 2023 and 2022. Construction, Land Development and Other Land Loans Agriculture and Agriculture Real Estate (includes Farmland) 1-4 Family (includes Home Equity) Commercial Real Estate (includes Multi-Family Residential) Commercial and Industrial Consumer and Other Total (Dollars in thousands) Allowance for credit losses on loans: Three Months Ended Balance June 30, 2023 $ 91,858 $ 11,254 $ 67,722 $ 86,765 $ 81,970 $ 5,640 $ 345,209 Initial allowance on loans purchased with credit deterioration 1,641 — — 4,290 3,763 — 9,694 Provision for credit losses on loans 1,437 149 3,932 ( 4,554 ) ( 2,455 ) 1,491 — Charge-offs — — ( 20 ) ( 584 ) ( 1,961 ) ( 1,550 ) ( 4,115 ) Recoveries 5 — 98 14 367 223 707 Net (charge-offs) recoveries 5 — 78 ( 570 ) ( 1,594 ) ( 1,327 ) ( 3,408 ) Balance September 30, 2023 $ 94,941 $ 11,403 $ 71,732 $ 85,931 $ 81,684 $ 5,804 $ 351,495 Nine Months Ended Balance December 31, 2022 $ 78,853 $ 7,699 $ 60,795 $ 66,272 $ 62,319 $ 5,638 $ 281,576 Initial allowance on loans purchased with credit deterioration 16,878 2,914 1,590 25,292 30,095 24 76,793 Provision for credit losses ( 758 ) 706 9,059 9,893 ( 10,448 ) 3,532 11,984 Charge-offs ( 77 ) ( 113 ) ( 121 ) ( 15,559 ) ( 3,203 ) ( 4,066 ) ( 23,139 ) Recoveries 45 197 409 33 2,921 676 4,281 Net (charge-offs) recoveries ( 32 ) 84 288 ( 15,526 ) ( 282 ) ( 3,390 ) ( 18,858 ) Balance September 30, 2023 $ 94,941 $ 11,403 $ 71,732 $ 85,931 $ 81,684 $ 5,804 $ 351,495 Allowance for credit losses on loans: Three Months Ended Balance June 30, 2022 $ 63,729 $ 8,338 $ 60,096 $ 70,011 $ 75,694 $ 6,091 $ 283,959 Provision for credit losses 2,454 ( 377 ) ( 1,213 ) ( 2,098 ) ( 37 ) 1,271 — Charge-offs — ( 119 ) ( 59 ) ( 757 ) ( 253 ) ( 1,386 ) ( 2,574 ) Recoveries 4 — 261 — 268 261 794 Net (charge-offs) recoveries 4 ( 119 ) 202 ( 757 ) 15 ( 1,125 ) ( 1,780 ) Balance September 30, 2022 $ 66,187 $ 7,842 $ 59,085 $ 67,156 $ 75,672 $ 6,237 $ 282,179 Nine Months Ended Balance December 31, 2021 $ 58,897 $ 7,759 $ 56,710 $ 75,005 $ 80,412 $ 7,597 $ 286,380 Provision for credit losses 7,711 90 2,228 ( 7,063 ) ( 4,938 ) 1,972 — Charge-offs ( 435 ) ( 274 ) ( 159 ) ( 796 ) ( 917 ) ( 4,061 ) ( 6,642 ) Recoveries 14 267 306 10 1,115 729 2,441 Net (charge-offs) recoveries ( 421 ) ( 7 ) 147 ( 786 ) 198 ( 3,332 ) ( 4,201 ) Balance September 30, 2022 $ 66,187 $ 7,842 $ 59,085 $ 67,156 $ 75,672 $ 6,237 $ 282,179 The allowance for credit losses on loans as of September 30, 2023 totaled $ 351.5 million or 1.64 % of total loans, including acquired loans with discounts, an increase of $ 69.9 million or 24.8 % compared to the allowance for credit losses on loans totaling $ 281.6 million or 1.49 % of total loans, including acquired loans with discounts, as of December 31, 2022 . There was no provision for credit losses for the three months ended September 30, 2023 and a provision for credit losses of $ 18.5 million for the nine months ended September 30, 2023 compared to no provision for credit losses for the three and nine months ended September 30, 2022. As a result of the loans acquired in the Merger that was completed on May 1, 2023, the second quarter of 2023 included a $ 12.0 million provision for credit losses on loans and a $ 6.5 million provision for credit losses on off-balance sheet credit exposures. Net charge-offs were $ 3.4 million for the three months ended September 30, 2023 compared to net charge-offs of $ 1.8 million for the three months ended September 30, 2022. Net charge-offs for the three months ended September 30, 2023 included $ 298 thousand related to resolved PCD loans. Additionally, reserves on PCD loans increased by $ 9.7 million due to revised Day One accounting for PCD loans at the time of the Merger. Further, $ 12.5 million of reserves on resolved PCD loans was released to the general reserve. Net charge-offs were $ 18.9 million for the nine months ended September 30, 2023 compared with $ 4.2 million for the nine months ended September 30, 2022. Net charge-offs for the nine months ended September 30, 2023 included $ 15.0 million related to one commercial real estate loan obtained in a previous merger. Additionally, reserves on PCD loans increased by $ 76.8 million due to the Merger and $ 16.2 million of reserves on resolved PCD loans was released to the general reserve. Allowance for Credit Losses on Off-Balance Sheet Credit Exposures. The allowance for credit losses on off-balance sheet credit exposures estimates expected credit losses over the contractual period in which there is exposure to credit risk via a contractual obligation to extend credit, except when an obligation is unconditionally cancellable by the Company. The allowance is adjusted by provisions for credit losses charged to earnings that increase the allowance, or by provision releases returned to earnings that decrease the allowance. The estimate includes consideration of the likelihood that funding will occur and an estimate of expected credit losses on the commitments expected to fund. The estimate of commitments expected to fund is affected by historical analysis of utilization rates. The expected credit loss rates applied to the commitments expected to fund are affected by the general valuation allowance utilized for outstanding balances with the same underlying assumptions and drivers. As of September 30, 2023 and December

Fair Value

Fair Value	9 Months Ended
Fair Value	Sep. 30, 2023
Fair Value Disclosures [Abstract]
Fair Value	6. FAIR VALUE The Company uses fair value measurements to record fair value adjustments to certain assets and to determine fair value disclosures. Fair values represent the estimated price that would be received from selling an asset or paid to transfer a liability, otherwise known as an “exit price.” Securities available for sale are recorded at fair value on a recurring basis. Additionally, from time to time, the Company may be required to record at fair value other assets on a nonrecurring basis. These nonrecurring fair value adjustments typically involve application of lower-of-cost-or-market accounting or write-downs of individual assets. ASC Topic 820, “Fair Value Measurements and Disclosures” 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: Fair Value Hierarchy The Company groups financial assets and financial liabilities measured at fair value in three levels, based on the markets in which the assets and liabilities are traded and the reliability of the assumptions used to determine fair value. These levels are: • Level 1—Quoted prices in active markets for identical assets or liabilities. • Level 2—Other significant observable inputs (including quoted prices in active markets for similar assets or liabilities) or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. • Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. 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, the Company utilizes 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. The fair value disclosures below represent the Company’s estimates based on relevant market information and information about the financial instruments. Fair value estimates are based on judgments regarding current economic conditions, risk characteristics of the various instruments and other factors. These estimates are subjective in nature and involve uncertainties and matters of significant judgment and therefore cannot be determined with precision. Changes in the above methodologies and assumptions could significantly affect the estimates. The following tables present fair values for assets and liabilities measured at fair value on a recurring basis: As of September 30, 2023 Level 1 Level 2 Level 3 Total (Dollars in thousands) Assets: Available for sale securities: Corporate debt securities $ — $ 21,485 $ — $ 21,485 Collateralized mortgage obligations — 327,524 — 327,524 Mortgage-backed securities — 97,156 — 97,156 Total $ — $ 446,165 $ — $ 446,165 Derivative financial instruments: Interest rate lock commitments $ — $ 302 $ — $ 302 Forward mortgage-backed securities trades — 240 — 240 Loan customer counterparty — — — — Financial institution counterparty — 5,660 — 5,660 Liabilities: Derivative financial instruments: Interest rate lock commitments $ — $ 35 $ — $ 35 Forward mortgage-backed securities trades — 3 — 3 Loan customer counterparty — 5,699 — 5,699 Financial institution counterparty — — — — As of December 31, 2022 Level 1 Level 2 Level 3 Total (Dollars in thousands) Assets: Available for sale securities: Collateralized mortgage obligations $ — $ 357,402 $ — $ 357,402 Mortgage-backed securities — 99,100 — 99,100 Total available for sale securities $ — $ 456,502 $ — $ 456,502 Derivative financial instruments: Interest rate lock commitments $ — $ 94 $ — $ 94 Forward mortgage-backed securities trades — 31 — 31 Loan customer counterparty — — — — Financial institution counterparty — 5,522 — 5,522 Liabilities: Derivative financial instruments: Interest rate lock commitments $ — $ 6 $ — $ 6 Forward mortgage-backed securities trades — — — — Loan customer counterparty — 5,522 — 5,522 Financial institution counterparty — — — — Certain assets and 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). These instruments include other real estate owned, repossessed assets, held to maturity debt securities, loans held for sale and impaired loans, which are included as loans held for investment. For the three and nine months ended September 30, 2023 , the Company had additions to other real estate owned of $ 8.6 million and $ 10.2 million, respectively, of which $ 8.2 million and $ 8.4 million, respectively, were outstanding as of September 30, 2023. For the three and nine months ended September 30, 2023 , the Company had additions to impaired loans of $ 13.7 million and $ 36.3 million, respectively, of which $ 13.7 million and $ 20.3 million, respectively, were outstanding as of September 30, 2023. The remaining financial assets and liabilities measured at fair value on a non-recurring basis that were recorded in 2023 and remained outstanding at September 30, 2023 were not significant. The following tables present carrying and fair value information of financial instruments as of the dates indicated: As of September 30, 2023 Carrying Estimated Fair Value Amount Level 1 Level 2 Level 3 Total (Dollars in thousands) Assets Cash and due from banks $ 512,239 $ 512,239 $ — $ — $ 512,239 Federal funds sold 234 234 — — 234 Held to maturity securities 12,746,577 — 10,834,219 — 10,834,219 Loans held for sale 10,187 — 10,187 — 10,187 Loans held for investment, net of allowance 20,158,704 — — 19,017,863 19,017,863 Loans held for investment - Warehouse Purchase Program 912,327 — 912,327 — 912,327 Other real estate owned 9,320 — 9,320 — 9,320 Liabilities Deposits: Noninterest-bearing $ 10,281,893 $ — $ 10,281,893 $ — $ 10,281,893 Interest-bearing 17,030,907 — 16,984,181 — 16,984,181 Other borrowings 4,250,000 — 4,179,418 — 4,179,418 Securities sold under repurchase agreements 300,714 — 300,662 — 300,662 As of December 31, 2022 Carrying Estimated Fair Value Amount Level 1 Level 2 Level 3 Total (Dollars in thousands) Assets Cash and due from banks $ 423,832 $ 423,832 $ — $ — $ 423,832 Federal funds sold 301 301 — — 301 Held to maturity securities 14,019,503 — 12,387,125 — 12,387,125 Loans held for sale 554 — 554 — 554 Loans held for investment, net of allowance 17,817,077 — — 17,550,309 17,550,309 Loans held for investment - Warehouse Purchase Program 740,620 — 740,620 — 740,620 Other real estate owned 1,963 — 1,963 — 1,963 Liabilities Deposits: Noninterest-bearing $ 10,915,448 $ — $ 10,915,448 $ — $ 10,915,448 Interest-bearing 17,618,083 — 17,563,711 — 17,563,711 Other borrowings 1,850,000 — 1,850,000 — 1,850,000 Securities sold under repurchase agreements 428,134 — 428,061 — 428,061 The following is a description of the fair value estimates, methods and assumptions that are used by the Company in estimating the fair values of financial instruments. Loans held for sale — Loans held for sale are carried at the lower of cost or estimated fair value. Fair value for consumer mortgages held for sale is based on commitments on hand from investors or prevailing market prices. As such, the Company classifies loans held for sale subjected to nonrecurring fair value adjustments as Level 2. Loans held for investment — The Company does not record loans at fair value on a recurring basis. As such, valuation techniques discussed herein for loans are primarily for estimating fair value disclosures. The Company refined the calculation to estimate fair value for loans held for investment to be in accordance with ASU 2016-01. The refined discounted cash flow calculation to determine fair value considers internal and market-based information such as prepayment risk, cost of funds and liquidity. From time to time, the Company records nonrecurring fair value adjustments to impaired loans to reflect (1) partial write-downs that are based on the observable market price or current appraised value of the collateral, or (2) the full charge-off of the loan carrying value. Where appraisals are not available, estimated cash flows are discounted using a rate commensurate with the credit risk associated with those cash flows. Assumptions regarding credit risk, cash flows and discount rates are judgmentally determined using available market information and specific borrower information. The Company classifies the estimated fair value of loans held for investment as Level 3. Other real estate owned — Other real estate owned is primarily foreclosed properties securing residential loans and commercial real estate loans. Foreclosed assets are adjusted to fair value less estimated costs to sell upon transfer of the loans to other real estate owned. Subsequently, these assets are carried at the lower of carrying value or fair value less estimated costs to sell. Other real estate carried at fair value based on an observable market price or a current appraised value is classified by the Company as Level 2. When management determines that the fair value of other real estate requires additional adjustments, either as a result of a non-current appraisal or when there is no observable market price, the Company classifies the other real estate as Level 3. The fair value estimates presented herein are based on pertinent information available to management at September 30, 2023 . Although management is not aware of any factors that would significantly affect the estimated fair value amounts, such amounts have not been comprehensively revalued for purposes of these financial statements since those dates and, therefore, current estimates of fair value may differ significantly from the amounts presented herein.

Goodwill and Core Deposit Intan

Goodwill and Core Deposit Intangibles	9 Months Ended
Goodwill and Core Deposit Intangibles	Sep. 30, 2023
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Core Deposit Intangibles	7. GOODWILL AND CORE DEPOSIT INTANGIBLES Changes in the carrying amount of the Company’s goodwill and core deposit intangibles for the nine months ended September 30, 2023 and the year ended December 31, 2022 were as follows: Goodwill Core Deposit Intangibles (Dollars in thousands) Balance as of December 31, 2021 $ 3,231,636 $ 61,684 Less: Amortization — ( 10,336 ) Balance as of December 31, 2022 3,231,636 51,348 Less: Amortization — ( 9,117 ) Add: First Bancshares Merger 164,823 25,322 Balance as of September 30, 2023 $ 3,396,459 $ 67,553 Goodwill is recorded as of the acquisition date of each entity. The Company may record subsequent adjustments to goodwill for amounts undeterminable at acquisition date, such as deferred taxes and real estate valuations, and therefore the goodwill amounts may change accordingly. The Company initially records the total premium paid on acquisitions as goodwill. After finalizing the valuation, core deposit intangibles are identified and reclassified from goodwill to core deposit intangibles on the balance sheet. This reclassification has no effect on total assets, liabilities, shareholders’ equity, net income or cash flows. Management performs an evaluation annually, and more frequently if a triggering event occurs, of whether any impairment of the goodwill or core deposit intangibles has occurred. If any such impairment is determined, a write-down is recorded. As of September 30, 2023 , there was no impairment recorded on goodwill and core deposit intangibles. The measurement period for the Company to determine the fair value of acquired identifiable assets and assumed liabilities will be at the end of the earlier of (1) twelve months from the date of acquisition or (2) as soon as the Company receives the information it was seeking about facts and circumstances that existed as of the date of acquisition. Core deposit intangibles are being amortized on a non-pro rata basis over their estimated lives, which the Company believes is between 10 and 15 years . Amortization expense related to intangible assets totaled $ 3.6 million and $ 2.6 million for the three months ended September 30, 2023 and 2022 , respectively, and $ 9.1 million and $ 7.8 million for the nine months ended September 30, 2023 and 2022 , respectively. The estimated aggregate future amortization expense for core deposit intangibles remaining as of September 30, 2023 is as follows (dollars in thousands): Remaining 2023 $ 3,559 2024 12,813 2025 11,410 2026 10,376 2027 9,288 Thereafter 20,107 Total $ 67,553

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
Stock-Based Compensation	Sep. 30, 2023
Share-Based Payment Arrangement [Abstract]
Stock-Based Compensation	8. STOCK–BASED COMPENSATION At September 30, 2023 , Bancshares had one active stock-based incentive compensation plan with awards outstanding. On March 3, 2020, Bancshares’ Board of Directors established the Prosperity Bancshares, Inc. 2020 Stock Incentive Plan (the “2020 Plan”), which was approved by Bancshares' shareholders on April 21, 2020. The 2020 Plan authorizes the issuance of up to 2,500,000 shares of common stock upon the exercise of options or pursuant to the grant or exercise, as the case may be, of other awards granted under the 2020 Plan, including incentive stock options, nonqualified stock options, stock appreciation rights, shares of restricted stock and restricted stock units. As of September 30, 2023 , 65,932 shares of restricted common stock have vested and 505,593 shares of unvested restricted stock have been issued under the 2020 Plan. As of September 30, 2023 , the Company had no stock options outstanding. Stock-based compensation expense related to restricted stock was $ 3.1 million and $ 2.9 million during the three months ended September 30, 2023 and 2022 , respectively, and $ 9.1 million and $ 8.5 million during the nine months ended September 30, 2023 and 2022, respectively. As of September 30, 2023 , there was $ 9.9 million of total unrecognized compensation expense related to stock-based compensation arrangements. That cost is expected to be recognized over a weighted average period of 1.99 years.

Contractual Obligations and Off

Contractual Obligations and Off-Balance Sheet Items	9 Months Ended
Contractual Obligations and Off-Balance Sheet Items	Sep. 30, 2023
Commitments and Contingencies Disclosure [Abstract]
Contractual Obligations and Off-Balance Sheet Items	9. CONTRACTUAL OBLIGATIONS AND OFF-BALANCE SHEET ITEMS Contractual Obligations The Company’s contractual obligations and other commitments to make future payments (other than deposit obligations and securities sold under repurchase agreements) as of September 30, 2023 are summarized below. The Company’s future cash payments associated with its contractual obligations pursuant to the Federal Reserve's Bank Term Funding Program (“BTFP”) and Federal Home Loan Bank (“FHLB”) advances as of September 30, 2023 are summarized below. The future interest payments were calculated using the current rate in effect at September 30, 2023 . Payments under the BTFP include interest of $ 102.8 million that will be due over the future periods. These payments do not include prepayment options that may be available to the Company. 1 year or less More than 1 year but less than 3 years 3 years or more but less than 5 years 5 years or more Total (Dollars in thousands) Bank Term Funding Program $ 3,102,848 — — — $ 3,102,848 Federal Home Loan Bank advances 1,250,000 — — — 1,250,000 $ 4,352,848 $ — $ — $ — $ 4,352,848 Leases The Company’s leases relate primarily to operating leases for office space and banking centers. The Company determines if an arrangement is a lease or contains a lease at inception. The Company’s leases have remaining lease terms of 1 to 15 years , which may include the option to extend the lease when it is reasonably certain for the Company to exercise that option. Operating lease right-of-use (ROU) assets and liabilities are recognized at the commencement date based on the present value of lease payments over the lease term. The Company uses its incremental collateralized borrowing rate to determine the present value of lease payments. Short-term leases and leases with variable lease costs are immaterial and the Company has one sublease arrangement. Sublease income was $ 816 thousand and $ 807 thousand for the three months ended September 30, 2023 and 2022 , and $ 2.3 million and $ 2.4 million for the nine months ended September 30, 2023 and 2022, respectively. As of September 30, 2023 , operating lease ROU assets and lease liabilities were approximately $ 38.6 million. ROU assets and lease liabilities were classified as other assets and other liabilities, respectively. As of September 30, 2023 , the weighted average of remaining lease terms of the Company’s operating leases was 4.2 years. The weighted average discount rate used to determine the lease liabilities as of September 30, 2023 for the Company’s operating leases was 2.0 %. Cash paid for the Company’s operating leases was $ 3.1 million and $ 2.7 million for the three months ended September 30, 2023 and 2022 , respectively, and was $ 9.0 million and $ 8.1 million for the nine months ended September 30, 2023 and 2022, respectively. During the nine months ended September 30, 2023 , the Company obtained $ 3.2 million in ROU assets in exchange for lease liabilities for seven operating leases, four of which, reflecting $ 2.7 million in ROU assets, were related to the Merger. The Company’s future undiscounted cash payments associated with its operating leases as of September 30, 2023 are summarized below (dollars in thousands). Remaining 2023 $ 2,696 2024 10,301 2025 9,737 2026 8,592 2027 5,569 2028 2,588 Thereafter 5,283 Total undiscounted lease payments $ 44,766 Off-Balance Sheet Items In the normal course of business, the Company enters into various transactions that, in accordance with GAAP, are not included in its consolidated balance sheets. The Company enters into these transactions to meet the financing needs of its 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. The Company’s commitments associated with outstanding standby letters of credit, unused capacity on Warehouse Purchase Program loans and commitments to extend credit expiring by period as of September 30, 2023 are summarized below. Since commitments associated with letters of credit, unused capacity of Warehouse Purchase Program loans and commitments to extend credit may expire unused, the amounts shown may not necessarily reflect the actual future cash funding requirements. 1 year or less More than 1 year but less than 3 years 3 years or more but less than 5 years 5 years or more Total (Dollars in thousands) Standby letters of credit $ 72,215 $ 7,456 $ 1,100 $ 26 $ 80,797 Unused capacity on Warehouse Purchase Program loans 1,170,673 — — — 1,170,673 Commitments to extend credit 1,728,337 1,080,668 306,129 1,898,917 5,014,051 Total $ 2,971,225 $ 1,088,124 $ 307,229 $ 1,898,943 $ 6,265,521 The Company records an allowance for credit losses on off-balance sheet credit exposure that is adjusted through a charge to provision for credit losses on the Company’s consolidated statement of income. At September 30, 2023 and December 31, 2022 , this allowance, reported as a separate line item on the Company’s consolidated balance sheet, totaled $ 36.5 million and $ 29.9 million, respectively. The increase in the allowance was primarily due to the Merger.

Other Comprehensive Income

Other Comprehensive Income	9 Months Ended
Other Comprehensive Income	Sep. 30, 2023
Equity [Abstract]
Other Comprehensive Income	10. OTHER COMPREHENSIVE INCOME The tax effects allocated to each component of other comprehensive income (loss) were as follows: Three Months Ended September 30, 2023 2022 Before Tax Amount Tax Effect Net of Tax Amount Before Tax Amount Tax Effect Net of Tax Amount (Dollars in thousands) Other comprehensive income (loss): Securities available for sale: Change in unrealized gain (loss) during period $ 951 $ ( 200 ) $ 751 $ ( 1,813 ) $ 380 $ ( 1,433 ) Total securities available for sale 951 ( 200 ) 751 ( 1,813 ) 380 ( 1,433 ) Total other comprehensive income (loss) $ 951 $ ( 200 ) $ 751 $ ( 1,813 ) $ 380 $ ( 1,433 ) Nine Months Ended September 30, 2023 2022 Before Tax Amount Tax Effect Net of Tax Amount Before Tax Amount Tax Effect Net of Tax Amount (Dollars in thousands) Other comprehensive income (loss): Securities available for sale: Change in unrealized gain (loss) during period $ 1,953 $ ( 410 ) $ 1,543 $ ( 2,587 ) $ 543 $ ( 2,044 ) Total securities available for sale 1,953 ( 410 ) 1,543 ( 2,587 ) 543 ( 2,044 ) Total other comprehensive income (loss) $ 1,953 $ ( 410 ) $ 1,543 $ ( 2,587 ) $ 543 $ ( 2,044 ) Activity in accumulated other comprehensive income (loss) associated with securities available for sale, net of tax, was as follows: Securities Available Accumulated Other Comprehensive Income (Loss) (Dollars in thousands) Balance at December 31, 2022 $ ( 3,473 ) $ ( 3,473 ) Other comprehensive income 1,543 1,543 Balance at September 30, 2023 $ ( 1,930 ) $ ( 1,930 ) Balance at December 31, 2021 $ 1,809 $ 1,809 Other comprehensive loss ( 2,044 ) ( 2,044 ) Balance at September 30, 2022 $ ( 235 ) $ ( 235 )

Derivative Financial Instrument

Derivative Financial Instruments	9 Months Ended
Derivative Financial Instruments	Sep. 30, 2023
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	11. DERIVATIVE FINANCIAL INSTRUMENTS The following table provides the outstanding notional balances and fair values of outstanding derivative positions at September 30, 2023 and December 31, 2022. September 30, 2023 December 31, 2022 Outstanding Asset Liability Derivative Outstanding Asset Liability Derivative (Dollars in thousands) Interest rate lock commitments $ 19,296 $ 302 $ 35 $ 4,599 $ 94 $ 6 Forward mortgage-backed securities trades 28,250 240 3 5,250 31 — Commercial loan interest rate swaps and caps: Loan customer counterparty 67,535 — 5,699 93,214 — 5,522 Financial institution counterparty 67,535 5,660 — 93,214 5,522 — These financial instruments are not designated as hedging instruments and are used for asset and liability management and commercial customers’ financing needs. All derivatives are carried at fair value in either other assets or other liabilities. Interest rate lock commitments (“IRLCs”) — In the normal course of business, the Company enters into interest rate lock commitments with consumers to originate mortgage loans at a specified interest rate. These commitments, which contain fixed expiration dates, offer the borrower an interest rate guarantee provided the loan meets underwriting guidelines and closes within the timeframe established by the Company. Forward mortgage-backed securities trades — The Company manages the changes in fair value associated with changes in interest rates related to IRLCs by using forward sold commitments known as forward mortgage-backed securities trades. These instruments are typically entered into at the time the interest rate lock commitment is made. Interest rate swaps and caps — These derivative positions relate to transactions in which the Company enters into an interest rate swap or cap with a customer, while at the same time entering into an offsetting interest rate swap or cap with another financial institution. An interest rate swap transaction allows the Company’s customer to effectively convert a variable rate loan to a fixed rate. In connection with each swap, the Company agrees 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, the Company agrees to pay another financial institution the same fixed interest rate on the same notional amount and receive the same variable interest rate on the same notional amount. In connection with each interest rate cap, the Company sells a cap to the customer and agrees to pay interest if the underlying index exceeds the strike price defined in the cap agreement. Simultaneously the Company purchases a cap with matching terms from another financial institution that agrees to pay the Company if the underlying index exceeds the strike price. The commercial loan customer counterparty weighted average received and paid interest rates for interest rate swaps outstanding at September 30, 2023 and December 31, 2022 are presented in the following table. Weighted-Average Interest Rate September 30, 2023 December 31, 2022 Received Paid Received Paid Loan customer counterparty 3.07 % 6.79 % 3.05 % 5.18 % The Company’s credit exposure on interest rate swaps is limited to the net favorable value of all swaps by each counterparty, which was approximately $ 5.7 million at September 30, 2023 and $ 5.5 million at December 31, 2022 . This credit exposure is partly mitigated as transactions with customers are secured by the collateral, if any, securing the underlying transaction being hedged. The Company’s credit exposure, net of collateral pledged, relating to interest rate swaps with upstream financial institution counter-parties was zero at September 30, 2023 . A credit support annex is in place and allows the Company to call collateral from upstream financial institution counter-parties. Collateral levels are monitored and adjusted on a regular basis for changes in interest rate swap values. The Company’s cash collateral pledged for interest rate swaps was zero at September 30, 2023 and December 31, 2022. The initial and subsequent changes in the fair value of IRLCs and the forward sales of mortgage-backed securities are recorded in net gain on sale of mortgage loans. These gains and losses were not attributable to instrument-specific credit risk. For interest rate swaps and caps, because the Company acts as an intermediary for its customer, changes in the fair value of the underlying derivative contracts substantially offset each other and do not have a material impact on its results of operations. Income (loss) for the three and nine months ended September 30, 2023 and 2022 was as follows: Three Months Ended September 30, Nine Months Ended September 30, Derivatives not designated as hedging instruments 2023 2022 2023 2022 (Dollars in thousands) Interest rate lock commitments $ ( 11 ) $ ( 264 ) $ 103 $ ( 269 ) Forward mortgage-backed securities trades 510 343 668 822

Acquisitions

Acquisitions	9 Months Ended
Acquisitions	Sep. 30, 2023
Business Combinations [Abstract]
Acquisitions	12. ACQUISITIONS Merger of First Bancshares of Texas, Inc . — Effective May 1, 2023, the Company completed the Merger of First Bancshares into Bancshares and the subsequent merger of its wholly owned subsidiary FirstCapital Bank into the Bank. FirstCapital Bank operated 16 full-service banking offices in six different markets in West, North and Central Texas areas, including its main office in Midland, and banking offices in Midland, Lubbock, Amarillo, Wichita Falls, Burkburnett, Byers, Henrietta, Dallas, Horseshoe Bay, Marble Falls and Fredericksburg, Texas. As of March 31, 2023, First Bancshares, on a consolidated basis, reported total assets of $ 2.14 billion, total loans of $ 1.65 billion and total deposits of $ 1.71 billion. The acquisition was not considered significant to the Company’s financial statements and therefore pro forma financial data and related disclosures are not included. Pursuant to the terms of the definitive agreement, Bancshares issued 3,583,370 shares of its common stock with a closing price of $ 62.62 per share plus approximately $ 91.5 million in cash for all outstanding shares of First Bancshares. As of September 30, 2023, the Company recognized goodwill of $ 164.8 million, which does not include all the subsequent fair value adjustments that have not yet been finalized. Goodwill represents the excess of the total purchase price paid over the fair value of the assets acquired, net of the fair value of liabilities assumed. During the second quarter of 2023, the Company completed the operational conversion of FirstCapital Bank. Pending Merger of Lone Star State Bancshares, Inc. — On October 11, 2022, Bancshares and Lone Star State Bancshares, Inc. (“Lone Star”) jointly announced the signing of a definitive merger agreement whereby Lone Star, the parent company of Lone Star State Bank of West Texas (“Lone Star Bank”), will merge with and into Bancshares. Lone Star Bank operates five banking offices in the West Texas area, including its main office in Lubbock, and one banking center in each of Brownfield, Midland, Odessa and Big Spring, Texas. As of September 30, 2023, Lone Star, on a consolidated basis, reported total assets of $ 1.27 billion, total loans of $ 1.10 billion and total deposits of $ 1.11 billion. Under the terms of the merger agreement, Bancshares will issue 2,376,182 shares of its common stock plus $ 64.1 million in cash for all outstanding shares of Lone Star capital stock, subject to certain conditions and potential adjustments. Based on the closing price of Bancshares’ common stock of $ 69.27 on October 7, 2022, the total consideration was valued at approximately $ 228.7 million. The transaction is subject to customary closing conditions, including the receipt of regulatory approvals. The shareholders of Lone Star approved the transaction on March 28, 2023.

New Accounting Standards (Polic

New Accounting Standards (Policies)	9 Months Ended
New Accounting Standards (Policies)	Sep. 30, 2023
Accounting Standards Update and Change in Accounting Principle [Abstract]
Accounting Standards Updates (''ASU'')	Accounting Standards Updates (“ASU”) ASU 2022-02, Financial Instruments—Credit Losses (Topic 326): Troubled Debt Restructurings and Vintage Disclosures. The amendments in ASU 2022-02 eliminated the accounting guidance for troubled debt restructurings and enhanced disclosures for certain loan refinancing and restructurings to borrowers experiencing financial difficulty. This guidance was applied on a prospective basis. Additionally, ASU 2022-02 requires entities to disclose current-period gross charge-offs by year of origination. ASU 2022-02 became effective for the Company on January 1, 2023 and did not have a significant impact on the Company’s financial statements. ASU 2020-04, Reference Rate Reform: Facilitation of the Effects of Reference Rate Reform on Financial Reporting – ASC Topic 848. ASU 2020-04 became effective for the Company on January 1, 2022 and provides optional expedients and exceptions for applying GAAP to loan and lease agreements, derivative contracts, and other transactions affected by the anticipated transition away from the London Inter-Bank Offered Rate (“LIBOR”) toward new interest rate benchmarks. ASU 2020-04 was effective upon issuance. In addition, the Financial Accounting Standards Board (“FASB”) issued ASU 2022-06 - Reference Rate Reform (Topic 848): Deferral of the Sunset Date of Topic 848 , which extends the period of time preparers can utilize the reference rate reform relief guidance provided by ASU 2020-04 from December 31, 2022 to December 31, 2024. ASU 2022-06 was effective upon issuance and did not change the core principles in ASU 2020-04. Prior to the end of 2021, the Company began transitioning away from LIBOR to the Secured Overnight Financing Rate (“SOFR”) or other alternative variable rate indexes for its interest-rate swaps and loans historically using LIBOR as an index. As of September 30, 2023, the Company's interest rate swaps and loan portfolio used SOFR as the index rate . As of December 31, 2022, LIBOR was used as an index rate for approximately 88.2 % of the Company’s interest-rate swaps and approximately 1.5 % of the Company’s loan portfolio. The adoption of ASU 2020-04 did not have a significant impact on the Company’s financial statements.

Income Per Common Share (Tables

Income Per Common Share (Tables)	9 Months Ended
Income Per Common Share (Tables)	Sep. 30, 2023
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	The following table illustrates the computation of basic and diluted earnings per share: Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Amount Per Share Amount Amount Per Share Amount Amount Per Share Amount Amount Per Share Amount (Amounts in thousands, except per share data) Net income $ 112,208 $ 135,820 $ 323,840 $ 386,636 Basic: Weighted average shares outstanding 93,720 $ 1.20 91,209 $ 1.49 92,628 $ 3.50 91,710 $ 4.22 Diluted: Weighted average shares outstanding 93,720 $ 1.20 91,209 $ 1.49 92,628 $ 3.50 91,710 $ 4.22

Securities (Tables)

Securities (Tables)	9 Months Ended
Securities (Tables)	Sep. 30, 2023
Investments, Debt and Equity Securities [Abstract]
Schedule of Amortized Cost and Fair Value of Investment Securities	The amortized cost and fair value of investment securities were as follows: September 30, 2023 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (Dollars in thousands) Available for Sale Corporate debt securities $ 20,698 $ 1,652 $ ( 865 ) $ 21,485 Collateralized mortgage obligations 329,465 1,018 ( 2,959 ) 327,524 Mortgage-backed securities 98,445 22 ( 1,311 ) 97,156 Total $ 448,608 $ 2,692 $ ( 5,135 ) $ 446,165 Held to Maturity U.S. Treasury securities and obligations of U.S. Government agencies $ 7,571 $ — $ ( 208 ) $ 7,363 States and political subdivisions 113,786 228 ( 4,723 ) 109,291 Corporate debt securities 12,000 — ( 4,560 ) 7,440 Collateralized mortgage obligations 271,570 — ( 29,507 ) 242,063 Mortgage-backed securities 12,341,650 64 ( 1,873,652 ) 10,468,062 Total $ 12,746,577 $ 292 $ ( 1,912,650 ) $ 10,834,219 December 31, 2022 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (Dollars in thousands) Available for Sale Collateralized mortgage obligations $ 359,251 $ 1,190 $ ( 3,039 ) $ 357,402 Mortgage-backed securities 101,647 93 ( 2,640 ) 99,100 Total $ 460,898 $ 1,283 $ ( 5,679 ) $ 456,502 Held to Maturity States and political subdivisions $ 122,361 $ 868 $ ( 3,255 ) $ 119,974 Corporate debt securities 12,000 — ( 2,520 ) 9,480 Collateralized mortgage obligations 271,727 377 ( 22,922 ) 249,182 Mortgage-backed securities 13,613,415 2,575 ( 1,607,501 ) 12,008,489 Total $ 14,019,503 $ 3,820 $ ( 1,636,198 ) $ 12,387,125
Securities in Continuous Loss Position	Securities with unrealized losses, segregated by length of time, that have been in a continuous loss position were as follows: September 30, 2023 Less than 12 Months 12 Months or More Total Estimated Fair Value Unrealized Losses Estimated Fair Value Unrealized Losses Estimated Fair Value Unrealized Losses (Dollars in thousands) Available for Sale Corporate debt securities $ 7,173 $ ( 865 ) $ — $ — $ 7,173 $ ( 865 ) Collateralized mortgage obligations 44,012 ( 373 ) 116,982 ( 2,586 ) 160,994 ( 2,959 ) Mortgage-backed securities 2,698 ( 55 ) 92,530 ( 1,256 ) 95,228 ( 1,311 ) Total $ 53,883 $ ( 1,293 ) $ 209,512 $ ( 3,842 ) $ 263,395 $ ( 5,135 ) Held to Maturity U.S. Treasury securities and obligations of U.S. Government agencies $ 7,363 $ ( 208 ) $ — $ — $ 7,363 $ ( 208 ) States and political subdivisions 50,902 ( 997 ) 39,698 ( 3,726 ) 90,600 ( 4,723 ) Corporate debt securities — — 7,440 ( 4,560 ) 7,440 ( 4,560 ) Collateralized mortgage obligations 51,009 ( 1,187 ) 191,012 ( 28,320 ) 242,021 ( 29,507 ) Mortgage-backed securities 227,436 ( 7,382 ) 10,235,113 ( 1,866,270 ) 10,462,549 ( 1,873,652 ) Total $ 336,710 $ ( 9,774 ) $ 10,473,263 $ ( 1,902,876 ) $ 10,809,973 $ ( 1,912,650 ) December 31, 2022 Less than 12 Months 12 Months or More Total Estimated Fair Value Unrealized Losses Estimated Fair Value Unrealized Losses Estimated Fair Value Unrealized Losses (Dollars in thousands) Available for Sale Collateralized mortgage obligations $ 61,559 $ ( 3,012 ) $ 99,179 $ ( 27 ) $ 160,738 $ ( 3,039 ) Mortgage-backed securities 95,212 ( 2,627 ) 291 ( 13 ) 95,503 ( 2,640 ) Total $ 156,771 $ ( 5,639 ) $ 99,470 $ ( 40 ) $ 256,241 $ ( 5,679 ) Held to Maturity States and political subdivisions $ 49,782 $ ( 885 ) $ 16,298 $ ( 2,370 ) $ 66,080 $ ( 3,255 ) Corporate debt securities 9,480 ( 2,520 ) — — 9,480 ( 2,520 ) Collateralized mortgage obligations 214,538 ( 22,557 ) 4,358 ( 365 ) 218,896 ( 22,922 ) Mortgage-backed securities 5,276,315 ( 416,053 ) 6,585,470 ( 1,191,448 ) 11,861,785 ( 1,607,501 ) Total $ 5,550,115 $ ( 442,015 ) $ 6,606,126 $ ( 1,194,183 ) $ 12,156,241 $ ( 1,636,198 )
Investment Securities by Contractual Maturity	The table below summarizes the amortized cost and fair value of investment securities at September 30, 2023, by contractual maturity. Actual maturities will differ from contractual maturities because borrowers may have the right to call or prepay obligations at any time with or without call or prepayment penalties. Held to Maturity Available for Sale Amortized Cost Fair Value Amortized Cost Fair Value (Dollars in thousands) Due in one year or less $ 25,590 $ 25,761 $ — $ — Due after one year through five years 49,927 48,679 2,550 2,865 Due after five years through ten years 45,822 39,137 18,148 18,620 Due after ten years 12,018 10,517 — — Subtotal 133,357 124,094 20,698 21,485 Mortgage-backed securities and collateralized mortgage obligations 12,613,220 10,710,125 427,910 424,680 Total $ 12,746,577 $ 10,834,219 $ 448,608 $ 446,165

Loans and Allowance for Credi_2

Loans and Allowance for Credit Losses (Tables)	9 Months Ended
Loans and Allowance for Credit Losses (Tables)	Sep. 30, 2023
Receivables [Abstract]
Types of Loans in Loan Portfolio	The loan portfolio consists of various types of loans and is categorized by major type as follows: September 30, 2023 December 31, 2022 (Dollars in thousands) Residential mortgage loans held for sale $ 10,187 $ 554 Commercial and industrial 2,603,028 2,594,742 Real estate: Construction, land development and other land loans 3,200,479 2,805,438 1-4 family residential (includes home equity) 7,991,904 6,740,670 Commercial real estate (includes multi-family residential) 5,606,837 4,986,211 Farmland 595,182 518,095 Agriculture 206,751 169,938 Consumer and other 306,018 283,559 Total loans held for investment, excluding Warehouse Purchase Program 20,510,199 18,098,653 Warehouse Purchase Program 912,327 740,620 Total loans, including Warehouse Purchase Program $ 21,432,713 $ 18,839,827
Related Party Loans	An analysis of activity with respect to these related party loans is as follows: As of and for the As of and for the 31, 2022 (Dollars in thousands) Beginning balance on January 1 $ 547 $ 6,524 New loans 57 54 Repayments ( 309 ) ( 6,031 ) Ending balance $ 295 $ 547
Aging Analysis of Past Due Loans	An aging analysis of past due loans, segregated by category of loan, is presented below: September 30, 2023 Loans Past Due and Still Accruing 30-89 Days 90 or More Days Total Past Due Loans Nonaccrual Loans Current Loans Total Loans (Dollars in thousands) Construction, land development and other land loans $ 9,238 $ — $ 9,238 $ 7,746 $ 3,183,495 $ 3,200,479 Warehouse Purchase Program loans — — — — 912,327 912,327 Agriculture and agriculture real estate (includes farmland) 3,755 — 3,755 1,511 796,667 801,933 1-4 family (includes home equity) (1) 34,229 — 34,229 23,439 7,944,423 8,002,091 Commercial real estate (includes multi-family residential) 5,974 — 5,974 5,228 5,595,635 5,606,837 Commercial and industrial 51,314 397 51,711 21,787 2,529,530 2,603,028 Consumer and other 493 — 493 18 305,507 306,018 Total $ 105,003 $ 397 $ 105,400 $ 59,729 $ 21,267,584 $ 21,432,713 December 31, 2022 Loans Past Due and Still Accruing 30-89 Days 90 or More Days Total Past Due Loans Nonaccrual Loans Current Loans Total Loans (Dollars in thousands) Construction, land development and other land loans $ 9,976 $ 4,442 $ 14,418 $ 318 $ 2,790,702 $ 2,805,438 Warehouse Purchase Program loans — — — — 740,620 740,620 Agriculture and agriculture real estate (includes farmland) 1,751 — 1,751 421 685,861 688,033 1-4 family (includes home equity) (1) 25,880 7 25,887 14,762 6,700,575 6,741,224 Commercial real estate (includes multi-family residential) 3,176 — 3,176 1,649 4,981,386 4,986,211 Commercial and industrial 10,575 1,468 12,043 2,453 2,580,246 2,594,742 Consumer and other 378 — 378 11 283,170 283,559 Total $ 51,736 $ 5,917 $ 57,653 $ 19,614 $ 18,762,560 $ 18,839,827 (1) Includes $ 10.2 million and $ 554 thousand of residential mortgage loans held for sale at September 30, 2023 and December 31, 2022 , respectively.
Non-performing Assets	The following table presents information regarding nonperforming assets as of the dates indicated: September 30, 2023 December 31, 2022 (Dollars in thousands) Nonaccrual loans (1) (3) $ 59,729 $ 19,614 (2) Accruing loans 90 or more days past due 397 5,917 Total nonperforming loans 60,126 25,531 Repossessed assets 35 — Other real estate 9,320 1,963 Total nonperforming assets $ 69,481 $ 27,494 Nonperforming assets to total loans and other real estate 0.32 % 0.15 % Nonperforming assets to total loans, excluding Warehouse Purchase Program loans, and other real estate 0.34 % 0.15 % Nonaccrual loans to total loans 0.28 % 0.10 % Nonaccrual loans to total loans, excluding Warehouse Purchase Program loans 0.29 % 0.11 % (1) ASU 2022-02 became effective for the Company on January 1, 2023. (2) Includes troubled debt restructurings of $ 4.6 million as of December 31, 2022 . (3) There were no nonperforming Warehouse Purchase Program loans or Warehouse Purchase Program lines of credit for the periods presented.
Recorded Investment and Outstanding Balance for Purchased Credit Deteriorated Loans and Non Purchased Credit Deteriorated Loans	The recorded investment in PCD loans included in the consolidated balance sheet and the related outstanding balance as of the dates indicated are presented in the table below. The outstanding balance represents the total amount owed as of September 30, 2023 and December 31, 2022. September 30, 2023 December 31, 2022 (Dollars in thousands) PCD loans: Outstanding balance $ 620,324 $ 63,383 Discount ( 9,343 ) ( 3,361 ) Recorded investment $ 610,981 $ 60,022 The recorded investment in Non-PCD loans included in the consolidated balance sheet and the related outstanding balance as of the dates indicated are presented in the table below. The outstanding balance represents the total amount owed as of September 30, 2023 and December 31, 2022. September 30, 2023 December 31, 2022 (Dollars in thousands) Non-PCD loans: Outstanding balance $ 1,959,822 $ 1,319,507 Discount ( 21,543 ) ( 2,233 ) Recorded investment $ 1,938,279 $ 1,317,274
Summary of Changes in Accretable Yields of Acquired Loans	Changes in the accretable yield for acquired PCD loans for the three and nine months ended September 30, 2023 and 2022 were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 (Dollars in thousands) Balance at beginning of period $ 10,110 $ 3,993 $ 3,361 $ 4,838 Additions — — 8,336 — Adjustments — — ( 70 ) — Accretion ( 767 ) ( 322 ) ( 2,284 ) ( 1,167 ) Balance at September 30, $ 9,343 $ 3,671 $ 9,343 $ 3,671 Changes in the discount accretion for Non-PCD loans for the three and nine months ended September 30, 2023 and 2022 were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 (Dollars in thousands) Balance at beginning of period $ 23,052 $ 3,734 $ 2,233 $ 8,143 Addition — — 22,593 — Accretion charge-offs ( 1 ) 14 ( 1 ) 14 Accretion ( 1,508 ) ( 912 ) ( 3,282 ) ( 5,321 ) Balance at September 30, $ 21,543 $ 2,836 $ 21,543 $ 2,836
Risk Grade by Category of Loan and Year of Origination/Renewal	The following tables present loans by risk grade, by category of loan and year of origination/renewal at September 30, 2023. Term Loans Amortized Cost Basis by Origination Year 2023 2022 2021 2020 2019 Prior Revolving Loans Revolving Loans Converted to Term Loans Total (Dollars in thousands) Construction, Land Development and Other Land Loans Grade 1 $ — $ — $ — $ — $ — $ — $ — $ — $ — Grade 2 1,136 178 — — — 70 — — 1,384 Grade 3 413,440 1,103,554 495,407 210,484 21,398 171,312 201,230 7,015 2,623,840 Grade 4 40,692 98,550 94,091 35,723 2,396 11,667 5,467 — 288,586 Grade 5 — — 4,399 — 18,678 629 915 — 24,621 Grade 6 — — 6,217 191 230 1,185 — — 7,823 Grade 7 — 928 1,647 3,318 — 1,587 266 — 7,746 Grade 8 — — — — — — — — — Grade 9 — — — — — — — — — PCD Loans 47,107 129,665 30,405 7,458 3,553 6,267 22,024 — 246,479 Total $ 502,375 $ 1,332,875 $ 632,166 $ 257,174 $ 46,255 $ 192,717 $ 229,902 $ 7,015 $ 3,200,479 Current-period gross write-offs $ — $ 77 $ — $ — $ — $ — $ — $ — $ 77 Agriculture and Agriculture Real Estate (includes Farmland) Grade 1 $ 1,002 $ 1,318 $ 323 $ 393 $ 19 $ 391 $ 8,770 $ — $ 12,216 Grade 2 — 75 104 — — 1,073 52 — 1,304 Grade 3 128,543 193,029 87,352 47,367 37,641 101,562 82,906 95 678,495 Grade 4 9,971 16,900 19,557 5,395 451 7,955 22,387 1,008 83,624 Grade 5 70 794 286 — 441 1,466 — — 3,057 Grade 6 — — 116 — — 478 — — 594 Grade 7 — — 1,334 — 15 162 — — 1,511 Grade 8 — — — — — — — — — Grade 9 — — — — — — — — — PCD Loans 216 2,333 1,769 3,793 1,214 3,604 2,914 5,289 21,132 Total $ 139,802 $ 214,449 $ 110,841 $ 56,948 $ 39,781 $ 116,691 $ 117,029 $ 6,392 $ 801,933 Current-period gross write-offs $ — $ — $ — $ 113 $ — $ — $ — $ — $ 113 1-4 Family (includes Home Equity) (1) Grade 1 $ 76 $ 158 $ — $ 110 $ — $ — $ — $ — $ 344 Grade 2 738 1,403 158 249 32 3,162 119 — 5,861 Grade 3 1,066,962 2,011,417 2,165,072 1,065,471 436,951 991,862 93,437 1,463 7,832,635 Grade 4 11,650 20,065 24,273 5,945 13,627 51,076 3,191 — 129,827 Grade 5 — 58 — 122 — 2,496 — — 2,676 Grade 6 — — 224 15 244 1,582 — — 2,065 Grade 7 244 3,984 5,244 3,528 1,904 8,459 76 — 23,439 Grade 8 — — — — — — — — — Grade 9 — — — — — — — — — PCD Loans 175 1,523 515 439 640 1,952 — — 5,244 Total $ 1,079,845 $ 2,038,608 $ 2,195,486 $ 1,075,879 $ 453,398 $ 1,060,589 $ 96,823 $ 1,463 $ 8,002,091 Current-period gross write-offs $ — $ 20 $ 50 $ 26 $ — $ 25 $ — $ — $ 121 Term Loans Amortized Cost Basis by Origination Year 2023 2022 2021 2020 2019 Prior Revolving Loans Revolving Loans Converted to Term Loans Total (Dollars in thousands) Commercial Real Estate (includes Multi-Family Residential) Grade 1 $ — $ — $ — $ — $ — $ — $ 48 $ — $ 48 Grade 2 — 1,439 — 483 — 2,467 — — 4,389 Grade 3 377,792 940,534 685,352 487,881 318,912 1,084,441 85,263 240 3,980,415 Grade 4 32,814 150,750 175,683 179,686 104,998 546,811 14,942 1,127 1,206,811 Grade 5 — — — — 14,988 45,636 1,555 — 62,179 Grade 6 — 934 1,548 11,946 15,938 89,267 — — 119,633 Grade 7 — 827 365 — 3,473 563 — — 5,228 Grade 8 — — — — — — — — — Grade 9 — — — — — — — — — PCD Loans 17,500 47,252 45,997 40,404 8,078 68,523 380 — 228,134 Total $ 428,106 $ 1,141,736 $ 908,945 $ 720,400 $ 466,387 $ 1,837,708 $ 102,188 $ 1,367 $ 5,606,837 Current-period gross write-offs $ — $ 14,975 $ — $ — $ — $ 584 $ — $ — $ 15,559 Commercial and Industrial Grade 1 $ 13,792 $ 11,407 $ 9,334 $ 3,841 $ 1,267 $ 5,054 $ 33,533 $ 43 $ 78,271 Grade 2 708 8,029 253 217 — 3,842 2,438 — 15,487 Grade 3 200,642 281,096 177,474 68,507 43,171 152,826 994,460 684 1,918,860 Grade 4 68,384 20,313 15,982 11,176 22,026 88,864 184,842 478 412,065 Grade 5 3,182 22,373 2,263 1,060 408 470 1,255 6,475 37,486 Grade 6 42 489 275 1,398 1,080 1,111 4,671 111 9,177 Grade 7 4,712 15,360 186 — 77 693 759 — 21,787 Grade 8 — — — — — — — — — Grade 9 — — — — — — — — — PCD Loans 6,410 23,067 11,847 4,755 5,658 1,156 56,805 197 109,895 Total $ 297,872 $ 382,134 $ 217,614 $ 90,954 $ 73,687 $ 254,016 $ 1,278,763 $ 7,988 $ 2,603,028 Current-period gross write-offs $ 10 $ 622 $ 145 $ 45 $ — $ 506 $ 1,875 $ — $ 3,203 Consumer and Other Grade 1 $ 11,930 $ 7,329 $ 3,463 $ 2,396 $ 1,314 $ 4,686 $ 1,873 $ — $ 32,991 Grade 2 12,584 14,202 — — — 2,009 7 — 28,802 Grade 3 61,873 43,988 28,130 28,237 11,606 11,571 49,034 92 234,531 Grade 4 1,926 290 1,191 1,068 1,301 572 3,231 — 9,579 Grade 5 — — — — — — — — — Grade 6 — — — — — — — — — Grade 7 — — — 15 3 — — — 18 Grade 8 — — — — — — — — — Grade 9 — — — — — — — — — PCD Loans — — 41 10 23 — 23 — 97 Total $ 88,313 $ 65,809 $ 32,825 $ 31,726 $ 14,247 $ 18,838 $ 54,168 $ 92 $ 306,018 Current-period gross write-offs $ 3,866 $ 71 $ 4 $ 27 $ 5 $ 20 $ 62 $ 11 $ 4,066 Term Loans Amortized Cost Basis by Origination Year 2023 2022 2021 2020 2019 Prior Revolving Loans Revolving Loans Converted to Term Loans Total (Dollars in thousands) Warehouse Purchase Program Grade 1 $ — $ — $ — $ — $ — $ — $ — $ — $ — Grade 2 — — — — — — — — — Grade 3 912,327 — — — — — — — 912,327 Grade 4 — — — — — — — — — Grade 5 — — — — — — — — — Grade 6 — — — — — — — — — Grade 7 — — — — — — — — — Grade 8 — — — — — — — — — Grade 9 — — — — — — — — — PCD Loans — — — — — — — — — Total $ 912,327 $ — $ — $ — $ — $ — $ — $ — $ 912,327 Current-period gross write-offs $ — $ — $ — $ — $ — $ — $ — $ — $ — Total Grade 1 $ 26,800 $ 20,212 $ 13,120 $ 6,740 $ 2,600 $ 10,131 $ 44,224 $ 43 $ 123,870 Grade 2 15,166 25,326 515 949 32 12,623 2,616 — 57,227 Grade 3 3,161,579 4,573,618 3,638,787 1,907,947 869,679 2,513,574 1,506,330 9,589 18,181,103 Grade 4 165,437 306,868 330,777 238,993 144,799 706,945 234,060 2,613 2,130,492 Grade 5 3,252 23,225 6,948 1,182 34,515 50,697 3,725 6,475 130,019 Grade 6 42 1,423 8,380 13,550 17,492 93,623 4,671 111 139,292 Grade 7 4,956 21,099 8,776 6,861 5,472 11,464 1,101 — 59,729 Grade 8 — — — — — — — — — Grade 9 — — — — — — — — — PCD Loans 71,408 203,840 90,574 56,859 19,166 81,502 82,146 5,486 610,981 Total $ 3,448,640 $ 5,175,611 $ 4,097,877 $ 2,233,081 $ 1,093,755 $ 3,480,559 $ 1,878,873 $ 24,317 $ 21,432,713 Current-period gross write-offs $ 3,876 $ 15,765 $ 199 $ 211 $ 5 $ 1,135 $ 1,937 $ 11 $ 23,139 (1) Includes $ 10.2 million of residential mortgage loans held for sale at September 30, 2023 .
Allowance for Credit Losses on Loans by Category of Loan	The following table details activity in the allowance for credit losses on loans by category of loan for the three and nine months ended September 30, 2023 and 2022. Construction, Land Development and Other Land Loans Agriculture and Agriculture Real Estate (includes Farmland) 1-4 Family (includes Home Equity) Commercial Real Estate (includes Multi-Family Residential) Commercial and Industrial Consumer and Other Total (Dollars in thousands) Allowance for credit losses on loans: Three Months Ended Balance June 30, 2023 $ 91,858 $ 11,254 $ 67,722 $ 86,765 $ 81,970 $ 5,640 $ 345,209 Initial allowance on loans purchased with credit deterioration 1,641 — — 4,290 3,763 — 9,694 Provision for credit losses on loans 1,437 149 3,932 ( 4,554 ) ( 2,455 ) 1,491 — Charge-offs — — ( 20 ) ( 584 ) ( 1,961 ) ( 1,550 ) ( 4,115 ) Recoveries 5 — 98 14 367 223 707 Net (charge-offs) recoveries 5 — 78 ( 570 ) ( 1,594 ) ( 1,327 ) ( 3,408 ) Balance September 30, 2023 $ 94,941 $ 11,403 $ 71,732 $ 85,931 $ 81,684 $ 5,804 $ 351,495 Nine Months Ended Balance December 31, 2022 $ 78,853 $ 7,699 $ 60,795 $ 66,272 $ 62,319 $ 5,638 $ 281,576 Initial allowance on loans purchased with credit deterioration 16,878 2,914 1,590 25,292 30,095 24 76,793 Provision for credit losses ( 758 ) 706 9,059 9,893 ( 10,448 ) 3,532 11,984 Charge-offs ( 77 ) ( 113 ) ( 121 ) ( 15,559 ) ( 3,203 ) ( 4,066 ) ( 23,139 ) Recoveries 45 197 409 33 2,921 676 4,281 Net (charge-offs) recoveries ( 32 ) 84 288 ( 15,526 ) ( 282 ) ( 3,390 ) ( 18,858 ) Balance September 30, 2023 $ 94,941 $ 11,403 $ 71,732 $ 85,931 $ 81,684 $ 5,804 $ 351,495 Allowance for credit losses on loans: Three Months Ended Balance June 30, 2022 $ 63,729 $ 8,338 $ 60,096 $ 70,011 $ 75,694 $ 6,091 $ 283,959 Provision for credit losses 2,454 ( 377 ) ( 1,213 ) ( 2,098 ) ( 37 ) 1,271 — Charge-offs — ( 119 ) ( 59 ) ( 757 ) ( 253 ) ( 1,386 ) ( 2,574 ) Recoveries 4 — 261 — 268 261 794 Net (charge-offs) recoveries 4 ( 119 ) 202 ( 757 ) 15 ( 1,125 ) ( 1,780 ) Balance September 30, 2022 $ 66,187 $ 7,842 $ 59,085 $ 67,156 $ 75,672 $ 6,237 $ 282,179 Nine Months Ended Balance December 31, 2021 $ 58,897 $ 7,759 $ 56,710 $ 75,005 $ 80,412 $ 7,597 $ 286,380 Provision for credit losses 7,711 90 2,228 ( 7,063 ) ( 4,938 ) 1,972 — Charge-offs ( 435 ) ( 274 ) ( 159 ) ( 796 ) ( 917 ) ( 4,061 ) ( 6,642 ) Recoveries 14 267 306 10 1,115 729 2,441 Net (charge-offs) recoveries ( 421 ) ( 7 ) 147 ( 786 ) 198 ( 3,332 ) ( 4,201 ) Balance September 30, 2022 $ 66,187 $ 7,842 $ 59,085 $ 67,156 $ 75,672 $ 6,237 $ 282,179
Rollforward of Allowance for Credit Losses on Off-Balance Sheet Credit Exposures	The following table represents a rollforward of the allowance for credit losses on off-balance sheet credit exposures for the periods shown. Three Months Ended September 30 Nine Months Ended September 30 2023 2022 2023 2022 (Dollars in thousands) Balance at beginning of period $ 36,503 $ 29,947 $ 29,947 $ 29,947 Provision for credit losses on off-balance sheet credit exposures — — 6,556 — Balance at end of period $ 36,503 $ 29,947 $ 36,503 $ 29,947
Schedule of Amortized Cost of Loans Experiencing Financial Difficulty and Modified	The following table displays the amortized cost of loans that were both experiencing financial difficulty and modified during the three and nine months ended September 30, 2023, presented by category of loan and type of modification. Payment Delay Term Extension Interest Rate Reduction Total Percentage of Total Loans Held for Investment (Dollars in thousands) Three Months Ended September 30, 2023 Commercial and industrial $ — $ 5,639 $ — $ 5,639 0.03 % Construction, land development and other land loans — — — — 0.00 % Commercial real estate (includes multi-family residential) — — 6,922 6,922 0.03 % Agriculture — 419 — 419 0.00 % Total $ — $ 6,058 $ 6,922 $ 12,980 0.05 % Nine Months Ended September 30, 2023 Commercial and industrial $ — $ 5,639 $ 292 $ 5,931 0.03 % Construction, land development and other land loans — 6,054 — 6,054 0.03 % Commercial real estate (includes multi-family residential) 1,294 — 6,922 8,216 0.04 % Agriculture — 419 — 419 0.00 % Total $ 1,294 $ 12,112 $ 7,214 $ 20,620 0.10 %
Schedule of Loan Modifications	The following tables describe the modifications made to loans whose borrowers are experiencing financial difficulty: Payment Delay Loan Type Three Months Ended September 30, 2023 Nine Months Ended September 30, 2023 Commercial real estate (includes multi-family residential) ̶̶̶ Short-term principal deferral Term Extension Loan Type Three Months Ended September 30, 2023 Nine Months Ended September 30, 2023 Commercial and industrial Short-term extension Short-term extension Construction, land development and other land loans ̶̶̶ Short-term extension Agriculture Short-term extension Short-term extension Interest Rate Reduction Loan Type Three Months Ended September 30, 2023 Nine Months Ended September 30, 2023 Commercial and industrial ̶̶̶ Reduced contractual interest rate Commercial real estate (includes multi-family residential) Reduced contractual interest rate Reduced contractual interest rate

Fair Value (Tables)

Fair Value (Tables)	9 Months Ended
Fair Value (Tables)	Sep. 30, 2023
Fair Value Disclosures [Abstract]
Fair Value Assets and Liabilities Measured on Recurring Basis	The following tables present fair values for assets and liabilities measured at fair value on a recurring basis: As of September 30, 2023 Level 1 Level 2 Level 3 Total (Dollars in thousands) Assets: Available for sale securities: Corporate debt securities $ — $ 21,485 $ — $ 21,485 Collateralized mortgage obligations — 327,524 — 327,524 Mortgage-backed securities — 97,156 — 97,156 Total $ — $ 446,165 $ — $ 446,165 Derivative financial instruments: Interest rate lock commitments $ — $ 302 $ — $ 302 Forward mortgage-backed securities trades — 240 — 240 Loan customer counterparty — — — — Financial institution counterparty — 5,660 — 5,660 Liabilities: Derivative financial instruments: Interest rate lock commitments $ — $ 35 $ — $ 35 Forward mortgage-backed securities trades — 3 — 3 Loan customer counterparty — 5,699 — 5,699 Financial institution counterparty — — — — As of December 31, 2022 Level 1 Level 2 Level 3 Total (Dollars in thousands) Assets: Available for sale securities: Collateralized mortgage obligations $ — $ 357,402 $ — $ 357,402 Mortgage-backed securities — 99,100 — 99,100 Total available for sale securities $ — $ 456,502 $ — $ 456,502 Derivative financial instruments: Interest rate lock commitments $ — $ 94 $ — $ 94 Forward mortgage-backed securities trades — 31 — 31 Loan customer counterparty — — — — Financial institution counterparty — 5,522 — 5,522 Liabilities: Derivative financial instruments: Interest rate lock commitments $ — $ 6 $ — $ 6 Forward mortgage-backed securities trades — — — — Loan customer counterparty — 5,522 — 5,522 Financial institution counterparty — — — —
Summary of Carrying and Fair Value Information of Financial Instruments	The following tables present carrying and fair value information of financial instruments as of the dates indicated: As of September 30, 2023 Carrying Estimated Fair Value Amount Level 1 Level 2 Level 3 Total (Dollars in thousands) Assets Cash and due from banks $ 512,239 $ 512,239 $ — $ — $ 512,239 Federal funds sold 234 234 — — 234 Held to maturity securities 12,746,577 — 10,834,219 — 10,834,219 Loans held for sale 10,187 — 10,187 — 10,187 Loans held for investment, net of allowance 20,158,704 — — 19,017,863 19,017,863 Loans held for investment - Warehouse Purchase Program 912,327 — 912,327 — 912,327 Other real estate owned 9,320 — 9,320 — 9,320 Liabilities Deposits: Noninterest-bearing $ 10,281,893 $ — $ 10,281,893 $ — $ 10,281,893 Interest-bearing 17,030,907 — 16,984,181 — 16,984,181 Other borrowings 4,250,000 — 4,179,418 — 4,179,418 Securities sold under repurchase agreements 300,714 — 300,662 — 300,662 As of December 31, 2022 Carrying Estimated Fair Value Amount Level 1 Level 2 Level 3 Total (Dollars in thousands) Assets Cash and due from banks $ 423,832 $ 423,832 $ — $ — $ 423,832 Federal funds sold 301 301 — — 301 Held to maturity securities 14,019,503 — 12,387,125 — 12,387,125 Loans held for sale 554 — 554 — 554 Loans held for investment, net of allowance 17,817,077 — — 17,550,309 17,550,309 Loans held for investment - Warehouse Purchase Program 740,620 — 740,620 — 740,620 Other real estate owned 1,963 — 1,963 — 1,963 Liabilities Deposits: Noninterest-bearing $ 10,915,448 $ — $ 10,915,448 $ — $ 10,915,448 Interest-bearing 17,618,083 — 17,563,711 — 17,563,711 Other borrowings 1,850,000 — 1,850,000 — 1,850,000 Securities sold under repurchase agreements 428,134 — 428,061 — 428,061

Goodwill and Core Deposit Int_2

Goodwill and Core Deposit Intangibles (Tables)	9 Months Ended
Goodwill and Core Deposit Intangibles (Tables)	Sep. 30, 2023
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Core Deposit Intangibles	Changes in the carrying amount of the Company’s goodwill and core deposit intangibles for the nine months ended September 30, 2023 and the year ended December 31, 2022 were as follows: Goodwill Core Deposit Intangibles (Dollars in thousands) Balance as of December 31, 2021 $ 3,231,636 $ 61,684 Less: Amortization — ( 10,336 ) Balance as of December 31, 2022 3,231,636 51,348 Less: Amortization — ( 9,117 ) Add: First Bancshares Merger 164,823 25,322 Balance as of September 30, 2023 $ 3,396,459 $ 67,553
Estimated Aggregate Future Amortization Expense for Core Deposit Intangibles	The estimated aggregate future amortization expense for core deposit intangibles remaining as of September 30, 2023 is as follows (dollars in thousands): Remaining 2023 $ 3,559 2024 12,813 2025 11,410 2026 10,376 2027 9,288 Thereafter 20,107 Total $ 67,553

Contractual Obligations and O_2

Contractual Obligations and Off-Balance Sheet Items (Tables)	9 Months Ended
	Sep. 30, 2023
Commitments and Contingencies Disclosure [Abstract]
Summary of Future Cash Payments Associated with Contractual Obligations Pursuant to Subordinated Debentures, Federal Reserve's Bank Term Funding Program and Federal Home Loan Bank Advances	The Company’s future cash payments associated with its contractual obligations pursuant to the Federal Reserve's Bank Term Funding Program (“BTFP”) and Federal Home Loan Bank (“FHLB”) advances as of September 30, 2023 are summarized below. 1 year or less More than 1 year but less than 3 years 3 years or more but less than 5 years 5 years or more Total (Dollars in thousands) Bank Term Funding Program $ 3,102,848 — — — $ 3,102,848 Federal Home Loan Bank advances 1,250,000 — — — 1,250,000 $ 4,352,848 $ — $ — $ — $ 4,352,848
Future Undiscounted Cash Payments Associated with its Operating Leases	The Company’s future undiscounted cash payments associated with its operating leases as of September 30, 2023 are summarized below (dollars in thousands). Remaining 2023 $ 2,696 2024 10,301 2025 9,737 2026 8,592 2027 5,569 2028 2,588 Thereafter 5,283 Total undiscounted lease payments $ 44,766
Summary of Commitments Associated with Outstanding Standby Letters of Credit, Unused Capacity on Warehouse Purchase Program Loans and Commitments to Extend Credit	The Company’s commitments associated with outstanding standby letters of credit, unused capacity on Warehouse Purchase Program loans and commitments to extend credit expiring by period as of September 30, 2023 are summarized below. Since commitments associated with letters of credit, unused capacity of Warehouse Purchase Program loans and commitments to extend credit may expire unused, the amounts shown may not necessarily reflect the actual future cash funding requirements. 1 year or less More than 1 year but less than 3 years 3 years or more but less than 5 years 5 years or more Total (Dollars in thousands) Standby letters of credit $ 72,215 $ 7,456 $ 1,100 $ 26 $ 80,797 Unused capacity on Warehouse Purchase Program loans 1,170,673 — — — 1,170,673 Commitments to extend credit 1,728,337 1,080,668 306,129 1,898,917 5,014,051 Total $ 2,971,225 $ 1,088,124 $ 307,229 $ 1,898,943 $ 6,265,521

Other Comprehensive Income (Tab

Other Comprehensive Income (Tables)	9 Months Ended
Other Comprehensive Income (Tables)	Sep. 30, 2023
Equity [Abstract]
Tax Effects Allocated to Each Component of Other Comprehensive Income (Loss)	The tax effects allocated to each component of other comprehensive income (loss) were as follows: Three Months Ended September 30, 2023 2022 Before Tax Amount Tax Effect Net of Tax Amount Before Tax Amount Tax Effect Net of Tax Amount (Dollars in thousands) Other comprehensive income (loss): Securities available for sale: Change in unrealized gain (loss) during period $ 951 $ ( 200 ) $ 751 $ ( 1,813 ) $ 380 $ ( 1,433 ) Total securities available for sale 951 ( 200 ) 751 ( 1,813 ) 380 ( 1,433 ) Total other comprehensive income (loss) $ 951 $ ( 200 ) $ 751 $ ( 1,813 ) $ 380 $ ( 1,433 ) Nine Months Ended September 30, 2023 2022 Before Tax Amount Tax Effect Net of Tax Amount Before Tax Amount Tax Effect Net of Tax Amount (Dollars in thousands) Other comprehensive income (loss): Securities available for sale: Change in unrealized gain (loss) during period $ 1,953 $ ( 410 ) $ 1,543 $ ( 2,587 ) $ 543 $ ( 2,044 ) Total securities available for sale 1,953 ( 410 ) 1,543 ( 2,587 ) 543 ( 2,044 ) Total other comprehensive income (loss) $ 1,953 $ ( 410 ) $ 1,543 $ ( 2,587 ) $ 543 $ ( 2,044 )
Activity in Accumulated Other Comprehensive Income (Loss) Associated with Securities Available for Sale, Net of Tax	Activity in accumulated other comprehensive income (loss) associated with securities available for sale, net of tax, was as follows: Securities Available Accumulated Other Comprehensive Income (Loss) (Dollars in thousands) Balance at December 31, 2022 $ ( 3,473 ) $ ( 3,473 ) Other comprehensive income 1,543 1,543 Balance at September 30, 2023 $ ( 1,930 ) $ ( 1,930 ) Balance at December 31, 2021 $ 1,809 $ 1,809 Other comprehensive loss ( 2,044 ) ( 2,044 ) Balance at September 30, 2022 $ ( 235 ) $ ( 235 )

Derivative Financial Instrume_2

Derivative Financial Instruments (Tables)	9 Months Ended
Derivative Financial Instruments (Tables)	Sep. 30, 2023
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Notional Balances and Fair Value of Derivative Positions	The following table provides the outstanding notional balances and fair values of outstanding derivative positions at September 30, 2023 and December 31, 2022. September 30, 2023 December 31, 2022 Outstanding Asset Liability Derivative Outstanding Asset Liability Derivative (Dollars in thousands) Interest rate lock commitments $ 19,296 $ 302 $ 35 $ 4,599 $ 94 $ 6 Forward mortgage-backed securities trades 28,250 240 3 5,250 31 — Commercial loan interest rate swaps and caps: Loan customer counterparty 67,535 — 5,699 93,214 — 5,522 Financial institution counterparty 67,535 5,660 — 93,214 5,522 —
Schedule of Weighted Average Received and Paid Interest Rates for Interest Rate Swaps Outstanding	The commercial loan customer counterparty weighted average received and paid interest rates for interest rate swaps outstanding at September 30, 2023 and December 31, 2022 are presented in the following table. Weighted-Average Interest Rate September 30, 2023 December 31, 2022 Received Paid Received Paid Loan customer counterparty 3.07 % 6.79 % 3.05 % 5.18 %
Schedule of Income (Loss) from Derivatives Not Designated as Hedging Instruments	Income (loss) for the three and nine months ended September 30, 2023 and 2022 was as follows: Three Months Ended September 30, Nine Months Ended September 30, Derivatives not designated as hedging instruments 2023 2022 2023 2022 (Dollars in thousands) Interest rate lock commitments $ ( 11 ) $ ( 264 ) $ 103 $ ( 269 ) Forward mortgage-backed securities trades 510 343 668 822

Income Per Common Share - Sched

Income Per Common Share - Schedule of Earnings Per Share, Basic and Diluted (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Earnings Per Share [Abstract]
Net income	$ 112,208	$ 135,820	$ 323,840	$ 386,636
Basic, Weighted average shares outstanding (in shares)	93,720	91,209	92,628	91,710
Basic	$ 1.2	$ 1.49	$ 3.5	$ 4.22
Diluted, Weighted average shares outstanding (in shares)	93,720	91,209	92,628	91,710
Diluted	$ 1.2	$ 1.49	$ 3.5	$ 4.22

Income Per Common Share - Addit

Income Per Common Share - Additional Information (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Earnings Per Share [Abstract]
Number of options outstanding	0		0
Antidilutive Securities excluded from computation of earnings per share, amount	0	0	0	0

New Accounting Standards - Addi

New Accounting Standards - Additional Information (Details)	9 Months Ended
New Accounting Standards - Additional Information (Details)	Sep. 30, 2023	Dec. 31, 2022
Accounting Standards Update and Change in Accounting Principle [Abstract]
Interest rate swaps and loans portfolio description of index rate basis	as the index rate
Percentage of interest rate swap which used LIBOR as an index rate		88.20%
Percentage of loan portfolio which used LIBOR as an index rate		1.50%

Securities - Schedule of Amorti

Securities - Schedule of Amortized Cost and Fair Value of Investment Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Marketable Securities [Line Items]
Available for Sale, Amortized Cost	$ 448,608	$ 460,898
Available for Sale, Gross Unrealized Gains	2,692	1,283
Available for Sale, Gross Unrealized Losses	(5,135)	(5,679)
Available for Sale	446,165	456,502
Held to Maturity, Amortized Cost	12,746,577	14,019,503
Held to Maturity, Gross Unrealized Gains	292	3,820
Held to Maturity, Gross Unrealized Losses	(1,912,650)	(1,636,198)
Held to Maturity	10,834,219	12,387,125
U.S. Treasury Securities and Obligations of U.S. Government Agencies [Member]
Marketable Securities [Line Items]
Held to Maturity, Amortized Cost	7,571
Held to Maturity, Gross Unrealized Losses	(208)
Held to Maturity	7,363
States and Political Subdivisions [Member]
Marketable Securities [Line Items]
Held to Maturity, Amortized Cost	113,786	122,361
Held to Maturity, Gross Unrealized Gains	228	868
Held to Maturity, Gross Unrealized Losses	(4,723)	(3,255)
Held to Maturity	109,291	119,974
Corporate Debt Securities [Member]
Marketable Securities [Line Items]
Available for Sale, Amortized Cost	20,698
Available for Sale, Gross Unrealized Gains	1,652
Available for Sale, Gross Unrealized Losses	(865)
Available for Sale	21,485
Held to Maturity, Amortized Cost	12,000	12,000
Held to Maturity, Gross Unrealized Losses	(4,560)	(2,520)
Held to Maturity	7,440	9,480
Collateralized Mortgage Obligations [Member]
Marketable Securities [Line Items]
Available for Sale, Amortized Cost	329,465	359,251
Available for Sale, Gross Unrealized Gains	1,018	1,190
Available for Sale, Gross Unrealized Losses	(2,959)	(3,039)
Available for Sale	327,524	357,402
Held to Maturity, Amortized Cost	271,570	271,727
Held to Maturity, Gross Unrealized Gains		377
Held to Maturity, Gross Unrealized Losses	(29,507)	(22,922)
Held to Maturity	242,063	249,182
Mortgage-backed Securities [Member]
Marketable Securities [Line Items]
Available for Sale, Amortized Cost	98,445	101,647
Available for Sale, Gross Unrealized Gains	22	93
Available for Sale, Gross Unrealized Losses	(1,311)	(2,640)
Available for Sale	97,156	99,100
Held to Maturity, Amortized Cost	12,341,650	13,613,415
Held to Maturity, Gross Unrealized Gains	64	2,575
Held to Maturity, Gross Unrealized Losses	(1,873,652)	(1,607,501)
Held to Maturity	$ 10,468,062	$ 12,008,489

Securities - Additional Informa

Securities - Additional Information (Details)	3 Months Ended		9 Months Ended		12 Months Ended
Securities - Additional Information (Details)	Sep. 30, 2023 USD ($) Security	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($) Segment Security	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($) Security
Schedule Of Held To Maturity Securities [Line Items]
Number of Investment Securities Segments \| Segment			2
Credit losses			$ 0
Municipal securities percentage of securities portfolio	0.90%		0.90%
Securities in Unrealized Loss Positions Qualitative Disclosure Number of Positions Greater Than or Equal to One Year \| Security	947		947		174
Gain (loss) on sale of securities	$ 0	$ 0	$ 0	$ 0
Available for Sale Securities, Amortized Cost Basis	448,608,000		448,608,000		$ 460,898,000
Debt Securities, Available-for-Sale	446,165,000		446,165,000		456,502,000
Collateralized Securities [Member]
Schedule Of Held To Maturity Securities [Line Items]
Available for Sale Securities, Amortized Cost Basis	10,330,000,000		10,330,000,000		7,870,000,000
Debt Securities, Available-for-Sale	$ 8,750,000,000		$ 8,750,000,000		$ 6,900,000,000
Securities Concentration Risk [Member] \| Stockholders' Equity, Total [Member] \| Other Than U.S. Government and Agencies [Member]
Schedule Of Held To Maturity Securities [Line Items]
Concentration Risk, Percentage			10%		10%

Securities - Securities in Cont

Securities - Securities in Continuous Loss Position (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Schedule Of Available For Sale Securities [Line Items]
Available for Sale, Estimated Fair Value, Less than 12 Months	$ 53,883	$ 156,771
Available for Sale, Unrealized Losses, Less than 12 Months	(1,293)	(5,639)
Available for Sale, Estimated Fair Value, 12 Months or More	209,512	99,470
Available for Sale, Unrealized Losses, 12 Months or More	(3,842)	(40)
Available for Sale, Estimated Fair Value, Total	263,395	256,241
Available for Sale, Unrealized Losses, Total	(5,135)	(5,679)
Held to Maturity, Estimated Fair Value, Less than 12 Months	336,710	5,550,115
Held to Maturity, Unrealized Losses, Less than 12 Months	(9,774)	(442,015)
Held to Maturity, Estimated Fair Value, 12 Months or More	10,473,263	6,606,126
Held to Maturity, Unrealized Losses, 12 Months or More	(1,902,876)	(1,194,183)
Held to Maturity, Estimated Fair Value, Total	10,809,973	12,156,241
Held to Maturity, Unrealized Losses, Total	(1,912,650)	(1,636,198)
U.S. Treasury Securities and Obligations of U.S. Government Agencies [Member]
Schedule Of Available For Sale Securities [Line Items]
Held to Maturity, Estimated Fair Value, Less than 12 Months	7,363
Held to Maturity, Unrealized Losses, Less than 12 Months	(208)
Held to Maturity, Estimated Fair Value, Total	7,363
Held to Maturity, Unrealized Losses, Total	(208)
States and Political Subdivisions [Member]
Schedule Of Available For Sale Securities [Line Items]
Held to Maturity, Estimated Fair Value, Less than 12 Months	50,902	49,782
Held to Maturity, Unrealized Losses, Less than 12 Months	(997)	(885)
Held to Maturity, Estimated Fair Value, 12 Months or More	39,698	16,298
Held to Maturity, Unrealized Losses, 12 Months or More	(3,726)	(2,370)
Held to Maturity, Estimated Fair Value, Total	90,600	66,080
Held to Maturity, Unrealized Losses, Total	(4,723)	(3,255)
Corporate Debt Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Available for Sale, Estimated Fair Value, Less than 12 Months	7,173
Available for Sale, Unrealized Losses, Less than 12 Months	(865)
Available for Sale, Estimated Fair Value, Total	7,173
Available for Sale, Unrealized Losses, Total	(865)
Held to Maturity, Estimated Fair Value, Less than 12 Months		9,480
Held to Maturity, Unrealized Losses, Less than 12 Months		(2,520)
Held to Maturity, Estimated Fair Value, 12 Months or More	7,440
Held to Maturity, Unrealized Losses, 12 Months or More	(4,560)
Held to Maturity, Estimated Fair Value, Total	7,440	9,480
Held to Maturity, Unrealized Losses, Total	(4,560)	(2,520)
Collateralized Mortgage Obligations [Member]
Schedule Of Available For Sale Securities [Line Items]
Available for Sale, Estimated Fair Value, Less than 12 Months	44,012	61,559
Available for Sale, Unrealized Losses, Less than 12 Months	(373)	(3,012)
Available for Sale, Estimated Fair Value, 12 Months or More	116,982	99,179
Available for Sale, Unrealized Losses, 12 Months or More	(2,586)	(27)
Available for Sale, Estimated Fair Value, Total	160,994	160,738
Available for Sale, Unrealized Losses, Total	(2,959)	(3,039)
Held to Maturity, Estimated Fair Value, Less than 12 Months	51,009	214,538
Held to Maturity, Unrealized Losses, Less than 12 Months	(1,187)	(22,557)
Held to Maturity, Estimated Fair Value, 12 Months or More	191,012	4,358
Held to Maturity, Unrealized Losses, 12 Months or More	(28,320)	(365)
Held to Maturity, Estimated Fair Value, Total	242,021	218,896
Held to Maturity, Unrealized Losses, Total	(29,507)	(22,922)
Mortgage-backed Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Available for Sale, Estimated Fair Value, Less than 12 Months	2,698	95,212
Available for Sale, Unrealized Losses, Less than 12 Months	(55)	(2,627)
Available for Sale, Estimated Fair Value, 12 Months or More	92,530	291
Available for Sale, Unrealized Losses, 12 Months or More	(1,256)	(13)
Available for Sale, Estimated Fair Value, Total	95,228	95,503
Available for Sale, Unrealized Losses, Total	(1,311)	(2,640)
Held to Maturity, Estimated Fair Value, Less than 12 Months	227,436	5,276,315
Held to Maturity, Unrealized Losses, Less than 12 Months	(7,382)	(416,053)
Held to Maturity, Estimated Fair Value, 12 Months or More	10,235,113	6,585,470
Held to Maturity, Unrealized Losses, 12 Months or More	(1,866,270)	(1,191,448)
Held to Maturity, Estimated Fair Value, Total	10,462,549	11,861,785
Held to Maturity, Unrealized Losses, Total	$ (1,873,652)	$ (1,607,501)

Securities - Investment Securit

Securities - Investment Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Investments, Debt and Equity Securities [Abstract]
Held to Maturity, amortized cost, due in one year or less	$ 25,590
Held to Maturity, amortized cost, due after one year through five years	49,927
Held to Maturity, amortized cost, due after five years through ten years	45,822
Held to Maturity, amortized cost, due after ten years	12,018
Held to Maturity, amortized cost, subtotal	133,357
Held to Maturity, amortized cost, mortgage-backed securities and collateralized mortgage obligations	12,613,220
Held to Maturity, Amortized Cost	12,746,577	$ 14,019,503
Held to Maturity, fair value, due in one year or less	25,761
Held to Maturity, fair value, due after one year through five years	48,679
Held to Maturity, fair value, due after five years through ten years	39,137
Held to Maturity, fair value, due after ten years	10,517
Held to Maturity, fair value, subtotal	124,094
Held to Maturity, fair value, mortgage-backed securities and collateralized mortgage obligations	10,710,125
Held to Maturity, fair value, total	10,834,219	12,387,125
Available for Sale, amortized cost, due after one year through five years	2,550
Available for Sale, amortized cost, due after five years through ten years	18,148
Available for Sale, amortized cost, subtotal	20,698
Available for Sale, amortized cost, mortgage-backed securities and collateralized mortgage obligations	427,910
Available for Sale, Amortized Cost	448,608	460,898
Available for Sale, fair value, due after one year through five years	2,865
Available for Sale, fair value, due after five years through ten years	18,620
Available for Sale, fair value, subtotal	21,485
Available for Sale, fair value, mortgage-backed securities and collateralized mortgage obligations	424,680
Available for Sale securities, at fair value	$ 446,165	$ 456,502

Loans and Allowance for Credi_3

Loans and Allowance for Credit Losses - Types of Loans in Loan Portfolio (Details) - USD ($) $ in Thousands		Sep. 30, 2023	Dec. 31, 2022
Accounts Notes And Loans Receivable [Line Items]
Loans held for sale		$ 10,187	$ 554
Loans held for investment		20,510,199	18,098,653
Total loans, including Warehouse Purchase Program		21,432,713	18,839,827
Residential Mortgage Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans held for sale		10,187	554
Commercial Real Estate (Includes Multi-Family Residential) [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans, including Warehouse Purchase Program		15,559
Warehouse Purchase Program [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment		912,327	740,620
Total loans, including Warehouse Purchase Program		912,327	740,620
Commercial and Industrial [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment		2,603,028	2,594,742
Total loans, including Warehouse Purchase Program		2,603,028	2,594,742
Real Estate [Member] \| Construction, Land Development and Other Land Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment		3,200,479	2,805,438
Total loans, including Warehouse Purchase Program		3,200,479	2,805,438
Real Estate [Member] \| 1-4 Family [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment		7,991,904	6,740,670
Total loans, including Warehouse Purchase Program	[1]	8,002,091	6,741,224
Real Estate [Member] \| Commercial Real Estate (Includes Multi-Family Residential) [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment		5,606,837	4,986,211
Total loans, including Warehouse Purchase Program		5,606,837	4,986,211
Real Estate [Member] \| Farmland [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment		595,182	518,095
Agriculture [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment		206,751	169,938
Consumer and Other [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment		306,018	283,559
Total loans, including Warehouse Purchase Program		$ 306,018	$ 283,559

[1] Includes $ 10.2 million and $ 554 thousand of residential mortgage loans held for sale at September 30, 2023 and December 31, 2022 , respectively.

Loans and Allowance for Credi_4

Loans and Allowance for Credit Losses - Additional Information (Details)	3 Months Ended			9 Months Ended
	Sep. 30, 2023 USD ($)	Jun. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($) Contract	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)	Jun. 30, 2022 USD ($)	Dec. 31, 2021 USD ($)
Accounts Notes And Loans Receivable [Line Items]
Percentage of Loans Related to Single Industry on Loans	10%			10%		10%
Percentage of real estate loans aggregating to company loan portfolio, excluding Warehouse Purchase Program loans	81.90%			81.90%		80.30%
Loans and Leases Receivable, Related Parties	$ 295,000			$ 295,000		$ 547,000		$ 6,524,000
Loans held for investment	$ 20,510,199,000			$ 20,510,199,000		$ 18,098,653,000
Financing Receivable Ratio of Nonperforming Loans to All Loans and Other Real Estate	0.32%			0.32%		0.15%
Loans and leases receivable, nonaccrual loans	$ 59,700,000			$ 59,700,000		$ 19,600,000
Financing Receivable, Allowance for Credit Losses on Loans	$ 351,500,000			$ 351,500,000		$ 281,600,000
Allowance for Credit Losses as Percentage of Loans	1.64%			1.64%		1.49%
Provision for credit losses			$ 0	$ 11,984,000	$ 0
Provision for credit losses				18,540,000
Increase in allowance for credit losses for loans				$ (69,900,000)
Decrease in allowance for credit losses for loans, percentage				24.80%
Net charge-offs	$ 3,408,000		1,780,000	$ 18,858,000	4,201,000
General reserve	12,500			16,200,000
Allowance for credit losses on off-balance sheet credit exposures	36,503,000	$ 36,503,000	29,947,000	36,503,000	29,947,000	$ 29,947,000	$ 29,947,000	$ 29,947,000
Commitments expected to fund	2,480,000,000			2,480,000,000
Nonaccrual loans	59,729,000			$ 59,729,000		19,614,000
Financing receivable, modifications, number of contract \| Contract				0
Restructured loans charge-off					0
First Bancshares of Texas, Inc. [Member]
Accounts Notes And Loans Receivable [Line Items]
Provision for credit losses		12,000,000
Merger [Member]
Accounts Notes And Loans Receivable [Line Items]
Net charge-offs	9,700,000			$ 76,800,000
Troubled Debt Restructuring [Member]
Accounts Notes And Loans Receivable [Line Items]
Allowance for credit losses on off-balance sheet credit exposures						29,900,000
Nonaccrual loans			$ 806,000		$ 806,000
Troubled Debt Restructuring [Member] \| First Bancshares of Texas, Inc. [Member]
Accounts Notes And Loans Receivable [Line Items]
Provision for credit losses		$ 6,500,000
PCD Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Net charge-offs	298,000
Nonperforming Financial Instruments [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	$ 69,500,000			69,500,000		$ 27,500,000
Commercial Real Estate Loan [Member]
Accounts Notes And Loans Receivable [Line Items]
Net charge-offs				$ 15,000,000

Loans and Allowance for Credi_5

Loans and Allowance for Credit Losses - Related Party Loans (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Receivables [Abstract]
Beginning balance on January 1	$ 547	$ 6,524
New loans	57	54
Repayments	(309)	(6,031)
Ending balance	$ 295	$ 547

Loans and Allowance for Credi_6

Loans and Allowance for Credit Losses - Aging Analysis of Past Due Loans (Details) - USD ($) $ in Thousands		Sep. 30, 2023	Dec. 31, 2022
Accounts Notes And Loans Receivable [Line Items]
Loans past due and still accruing		$ 21,267,584	$ 18,762,560
Nonaccrual loans		59,729	19,614
Total loans		21,432,713	18,839,827
Financing Receivables, 30 to 89 Days Past Due [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans past due and still accruing		105,003	51,736
Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans past due and still accruing		397	5,917
Financing Receivables Past Due Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans past due and still accruing		105,400	57,653
Warehouse Purchase Program Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans past due and still accruing		912,327	740,620
Total loans		912,327	740,620
Agriculture [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans past due and still accruing		796,667	685,861
Nonaccrual loans		1,511	421
Total loans		801,933	688,033
Agriculture [Member] \| Financing Receivables, 30 to 89 Days Past Due [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans past due and still accruing		3,755	1,751
Agriculture [Member] \| Financing Receivables Past Due Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans past due and still accruing		3,755	1,751
Commercial Real Estate (Includes Multi-Family Residential) [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans		15,559
Real Estate [Member] \| Construction, Land Development and Other Land Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans past due and still accruing		3,183,495	2,790,702
Nonaccrual loans		7,746	318
Total loans		3,200,479	2,805,438
Real Estate [Member] \| Construction, Land Development and Other Land Loans [Member] \| Financing Receivables, 30 to 89 Days Past Due [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans past due and still accruing		9,238	9,976
Real Estate [Member] \| Construction, Land Development and Other Land Loans [Member] \| Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans past due and still accruing			4,442
Real Estate [Member] \| Construction, Land Development and Other Land Loans [Member] \| Financing Receivables Past Due Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans past due and still accruing		9,238	14,418
Real Estate [Member] \| Agriculture [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans		801,933
Real Estate [Member] \| 1-4 Family Residential (Includes Home Equity) [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans past due and still accruing	[1]	7,944,423	6,700,575
Nonaccrual loans	[1]	23,439	14,762
Total loans	[1]	8,002,091	6,741,224
Real Estate [Member] \| 1-4 Family Residential (Includes Home Equity) [Member] \| Financing Receivables, 30 to 89 Days Past Due [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans past due and still accruing	[1]	34,229	25,880
Real Estate [Member] \| 1-4 Family Residential (Includes Home Equity) [Member] \| Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans past due and still accruing	[1]		7
Real Estate [Member] \| 1-4 Family Residential (Includes Home Equity) [Member] \| Financing Receivables Past Due Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans past due and still accruing	[1]	34,229	25,887
Real Estate [Member] \| Commercial Real Estate (Includes Multi-Family Residential) [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans past due and still accruing		5,595,635	4,981,386
Nonaccrual loans		5,228	1,649
Total loans		5,606,837	4,986,211
Real Estate [Member] \| Commercial Real Estate (Includes Multi-Family Residential) [Member] \| Financing Receivables, 30 to 89 Days Past Due [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans past due and still accruing		5,974	3,176
Real Estate [Member] \| Commercial Real Estate (Includes Multi-Family Residential) [Member] \| Financing Receivables Past Due Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans past due and still accruing		5,974	3,176
Commercial and Industrial [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans past due and still accruing		2,529,530	2,580,246
Nonaccrual loans		21,787	2,453
Total loans		2,603,028	2,594,742
Commercial and Industrial [Member] \| Financing Receivables, 30 to 89 Days Past Due [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans past due and still accruing		51,314	10,575
Commercial and Industrial [Member] \| Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans past due and still accruing		397	1,468
Commercial and Industrial [Member] \| Financing Receivables Past Due Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans past due and still accruing		51,711	12,043
Consumer and Other [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans past due and still accruing		305,507	283,170
Nonaccrual loans		18	11
Total loans		306,018	283,559
Consumer and Other [Member] \| Financing Receivables, 30 to 89 Days Past Due [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans past due and still accruing		493	378
Consumer and Other [Member] \| Financing Receivables Past Due Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans past due and still accruing		$ 493	$ 378

[1] Includes $ 10.2 million and $ 554 thousand of residential mortgage loans held for sale at September 30, 2023 and December 31, 2022 , respectively.

Loans and Allowance for Credi_7

Loans and Allowance for Credit Losses - Aging Analysis of Past Due Loans (Parenthetical) (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Accounts Notes And Loans Receivable [Line Items]
Loans held for sale	$ 10,187	$ 554
Residential Mortgage Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans held for sale	$ 10,187	$ 554

Loans and Allowance for Credi_8

Loans and Allowance for Credit Losses - Nonperforming Assets (Details) - USD ($) $ in Thousands		Sep. 30, 2023	Dec. 31, 2022
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment		$ 20,510,199	$ 18,098,653
Other real estate owned		$ 9,320	$ 1,963
Nonperforming assets to total loans and other real estate		0.32%	0.15%
Nonperforming assets to total loans, excluding Warehouse Purchase Program loans, and other real estate		0.34%	0.15%
Nonaccrual loans to total loans		0.28%	0.10%
Nonaccrual loans to total loans, excluding Warehouse Purchase Program loans		0.29%	0.11%
Nonperforming Financial Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment		$ 60,126	$ 25,531
Repossessed assets		35
Other real estate owned		9,320	1,963
Total nonperforming assets		69,481	27,494
Nonperforming Financial Loans [Member] \| Finance Receivable Nonaccrual Status [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	[1],[2],[3]	59,729	19,614
Nonperforming Financial Loans [Member] \| Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment		$ 397	$ 5,917

[1] ASU 2022-02 became effective for the Company on January 1, 2023. Includes troubled debt restructurings of $ 4.6 million as of December 31, 2022 . There were no nonperforming Warehouse Purchase Program loans or Warehouse Purchase Program lines of credit for the periods presented.

Loans and Allowance for Credi_9

Loans and Allowance for Credit Losses - Nonperforming Assets (Parenthetical) (Details) - USD ($)		Sep. 30, 2023	Dec. 31, 2022
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment		$ 20,510,199,000	$ 18,098,653,000
Nonperforming Financial Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment		60,126,000	25,531,000
Nonperforming Financial Loans [Member] \| Finance Receivable Nonaccrual Status [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment	[1],[2],[3]	59,729,000	19,614,000
Troubled Debt Restructuring [Member] \| Nonperforming Financial Loans [Member] \| Finance Receivable Nonaccrual Status [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment			4,600,000
Troubled Debt Restructuring [Member] \| Nonperforming Financial Loans [Member] \| Finance Receivable Nonaccrual Status [Member] \| Warehouse Purchase Program [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans held for investment		$ 0	$ 0

[1] ASU 2022-02 became effective for the Company on January 1, 2023. Includes troubled debt restructurings of $ 4.6 million as of December 31, 2022 . There were no nonperforming Warehouse Purchase Program loans or Warehouse Purchase Program lines of credit for the periods presented.

Loans and Allowance for Cred_10

Loans and Allowance for Credit Losses - Recorded Investment and Outstanding Balance for Purchased Credit Deteriorated Loans and Non Purchased Credit Deteriorated Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
PCD Loans [Member]
Purchased And Non Purchased Credit Impaired Loans [Line Items]
Outstanding balance	$ 620,324	$ 63,383
Discount	(9,343)	(3,361)
Recorded investment	610,981	60,022
Non-PCD Loans [Member]
Purchased And Non Purchased Credit Impaired Loans [Line Items]
Outstanding balance	1,959,822	1,319,507
Discount	(21,543)	(2,233)
Recorded investment	$ 1,938,279	$ 1,317,274

Loans and Allowance for Cred_11

Loans and Allowance for Credit Losses - Summary of Changes in Accretable Yields of Acquired Loans (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
PCD Loans [Member]
Changes In Accretable Yield for PCI And Non PCI Loans [Line Items]
Balance at beginning of period	$ 10,110	$ 3,993	$ 3,361	$ 4,838
Addition			8,336
Adjustments			(70)
Accretion	(767)	(322)	(2,284)	(1,167)
Balance at September 30,	9,343	3,671	9,343	3,671
Non-PCD Loans [Member]
Changes In Accretable Yield for PCI And Non PCI Loans [Line Items]
Balance at beginning of period	23,052	3,734	2,233	8,143
Addition			22,593
Accretion charge-offs	1	(14)	1	(14)
Accretion	(1,508)	(912)	(3,282)	(5,321)
Balance at September 30,	$ 21,543	$ 2,836	$ 21,543	$ 2,836

Loans and Allowance for Cred_12

Loans and Allowance for Credit Losses - Risk Grade by Category of Loan and Year of Origination/Renewal (Details) - USD ($) $ in Thousands		Sep. 30, 2023	Dec. 31, 2022
Financing Receivable Impaired [Line Items]
2023		$ 3,448,640
2022		5,175,611
2021		4,097,877
2020		2,233,081
2019		1,093,755
Prior		3,480,559
Revolving Loans		1,878,873
Revolving Loans Converted to Term Loans		24,317
Total loans		21,432,713	$ 18,839,827
Current-period gross write-offs, 2023		3,876
Current-period gross write-offs, 2022		15,765
Current-period gross write-offs, 2021		199
Current-period gross write-offs, 2020		211
Current-period gross write-offs, 2019		5
Current-period gross write-offs, Prior		1,135
Current-period gross write-offs, Revolving Loans		1,937
Current-period gross write-offs, Revolving Loans Converted to Term Loans		11
Current-period gross write-offs, Total		23,139
PCD Loans [Member]
Financing Receivable Impaired [Line Items]
2023		71,408
2022		203,840
2021		90,574
2020		56,859
2019		19,166
Prior		81,502
Revolving Loans		82,146
Revolving Loans Converted to Term Loans		5,486
Total loans		610,981
Agriculture [Member]
Financing Receivable Impaired [Line Items]
Total loans		801,933	688,033
Commercial Real Estate (Includes Multi-Family Residential) [Member]
Financing Receivable Impaired [Line Items]
Total loans		15,559
Current-period gross write-offs, 2022		14,975
Current-period gross write-offs, Prior		584
Warehouse Purchase Program [Member]
Financing Receivable Impaired [Line Items]
2023		912,327
Total loans		912,327	740,620
Real Estate [Member] \| Construction, Land Development and Other Land Loans [Member]
Financing Receivable Impaired [Line Items]
2023		502,375
2022		1,332,875
2021		632,166
2020		257,174
2019		46,255
Prior		192,717
Revolving Loans		229,902
Revolving Loans Converted to Term Loans		7,015
Total loans		3,200,479	2,805,438
Current-period gross write-offs, 2022		77
Current-period gross write-offs, Total		77
Real Estate [Member] \| Construction, Land Development and Other Land Loans [Member] \| PCD Loans [Member]
Financing Receivable Impaired [Line Items]
2023		47,107
2022		129,665
2021		30,405
2020		7,458
2019		3,553
Prior		6,267
Revolving Loans		22,024
Total loans		246,479
Real Estate [Member] \| Agriculture [Member]
Financing Receivable Impaired [Line Items]
2023		139,802
2022		214,449
2021		110,841
2020		56,948
2019		39,781
Prior		116,691
Revolving Loans		117,029
Revolving Loans Converted to Term Loans		6,392
Total loans		801,933
Current-period gross write-offs, 2020		113
Current-period gross write-offs, Total		113
Real Estate [Member] \| Agriculture [Member] \| PCD Loans [Member]
Financing Receivable Impaired [Line Items]
2023		216
2022		2,333
2021		1,769
2020		3,793
2019		1,214
Prior		3,604
Revolving Loans		2,914
Revolving Loans Converted to Term Loans		5,289
Total loans		21,132
Real Estate [Member] \| 1-4 Family [Member]
Financing Receivable Impaired [Line Items]
2023		1,079,845
2022		2,038,608
2021		2,195,486
2020		1,075,879
2019		453,398
Prior		1,060,589
Revolving Loans		96,823
Revolving Loans Converted to Term Loans		1,463
Total loans	[1]	8,002,091	6,741,224
Current-period gross write-offs, 2022		20
Current-period gross write-offs, 2021		50
Current-period gross write-offs, 2020		26
Current-period gross write-offs, Prior		25
Current-period gross write-offs, Total		121
Real Estate [Member] \| 1-4 Family [Member] \| PCD Loans [Member]
Financing Receivable Impaired [Line Items]
2023		175
2022		1,523
2021		515
2020		439
2019		640
Prior		1,952
Total loans		5,244
Real Estate [Member] \| Commercial Real Estate (Includes Multi-Family Residential) [Member]
Financing Receivable Impaired [Line Items]
2023		428,106
2022		1,141,736
2021		908,945
2020		720,400
2019		466,387
Prior		1,837,708
Revolving Loans		102,188
Revolving Loans Converted to Term Loans		1,367
Total loans		5,606,837	4,986,211
Real Estate [Member] \| Commercial Real Estate (Includes Multi-Family Residential) [Member] \| PCD Loans [Member]
Financing Receivable Impaired [Line Items]
2023		17,500
2022		47,252
2021		45,997
2020		40,404
2019		8,078
Prior		68,523
Revolving Loans		380
Total loans		228,134
Commercial and Industrial [Member]
Financing Receivable Impaired [Line Items]
2023		297,872
2022		382,134
2021		217,614
2020		90,954
2019		73,687
Prior		254,016
Revolving Loans		1,278,763
Revolving Loans Converted to Term Loans		7,988
Total loans		2,603,028	2,594,742
Current-period gross write-offs, 2023		3,866
Current-period gross write-offs, 2022		71
Current-period gross write-offs, 2021		4
Current-period gross write-offs, 2020		27
Current-period gross write-offs, Prior		20
Current-period gross write-offs, Revolving Loans		62
Current-period gross write-offs, Revolving Loans Converted to Term Loans		11
Current-period gross write-offs, Total		4,066
Commercial and Industrial [Member] \| PCD Loans [Member]
Financing Receivable Impaired [Line Items]
2023		6,410
2022		23,067
2021		11,847
2020		4,755
2019		5,658
Prior		1,156
Revolving Loans		56,805
Revolving Loans Converted to Term Loans		197
Total loans		109,895
Consumer and Other [Member]
Financing Receivable Impaired [Line Items]
2023		88,313
2022		65,809
2021		32,825
2020		31,726
2019		14,247
Prior		18,838
Revolving Loans		54,168
Revolving Loans Converted to Term Loans		92
Total loans		306,018	$ 283,559
Current-period gross write-offs, 2023		10
Current-period gross write-offs, 2022		622
Current-period gross write-offs, 2021		145
Current-period gross write-offs, 2020		45
Current-period gross write-offs, 2019		5
Current-period gross write-offs, Prior		506
Current-period gross write-offs, Revolving Loans		1,875
Current-period gross write-offs, Total		3,203
Consumer and Other [Member] \| PCD Loans [Member]
Financing Receivable Impaired [Line Items]
2021		41
2020		10
2019		23
Revolving Loans		23
Total loans		97
Grade 1 [Member]
Financing Receivable Impaired [Line Items]
2023		26,800
2022		20,212
2021		13,120
2020		6,740
2019		2,600
Prior		10,131
Revolving Loans		44,224
Revolving Loans Converted to Term Loans		43
Total loans		123,870
Grade 1 [Member] \| Real Estate [Member] \| Agriculture [Member]
Financing Receivable Impaired [Line Items]
2023		1,002
2022		1,318
2021		323
2020		393
2019		19
Prior		391
Revolving Loans		8,770
Total loans		12,216
Grade 1 [Member] \| Real Estate [Member] \| 1-4 Family [Member]
Financing Receivable Impaired [Line Items]
2023		76
2022		158
2020		110
Total loans		344
Grade 1 [Member] \| Real Estate [Member] \| Commercial Real Estate (Includes Multi-Family Residential) [Member]
Financing Receivable Impaired [Line Items]
Revolving Loans		48
Total loans		48
Grade 1 [Member] \| Commercial and Industrial [Member]
Financing Receivable Impaired [Line Items]
2023		13,792
2022		11,407
2021		9,334
2020		3,841
2019		1,267
Prior		5,054
Revolving Loans		33,533
Revolving Loans Converted to Term Loans		43
Total loans		78,271
Grade 1 [Member] \| Consumer and Other [Member]
Financing Receivable Impaired [Line Items]
2023		11,930
2022		7,329
2021		3,463
2020		2,396
2019		1,314
Prior		4,686
Revolving Loans		1,873
Total loans		32,991
Grade 2 [Member]
Financing Receivable Impaired [Line Items]
2023		15,166
2022		25,326
2021		515
2020		949
2019		32
Prior		12,623
Revolving Loans		2,616
Total loans		57,227
Grade 2 [Member] \| Real Estate [Member] \| Construction, Land Development and Other Land Loans [Member]
Financing Receivable Impaired [Line Items]
2023		1,136
2022		178
Prior		70
Total loans		1,384
Grade 2 [Member] \| Real Estate [Member] \| Agriculture [Member]
Financing Receivable Impaired [Line Items]
2022		75
2021		104
Prior		1,073
Revolving Loans		52
Total loans		1,304
Grade 2 [Member] \| Real Estate [Member] \| 1-4 Family [Member]
Financing Receivable Impaired [Line Items]
2023		738
2022		1,403
2021		158
2020		249
2019		32
Prior		3,162
Revolving Loans		119
Total loans		5,861
Grade 2 [Member] \| Real Estate [Member] \| Commercial Real Estate (Includes Multi-Family Residential) [Member]
Financing Receivable Impaired [Line Items]
2022		1,439
2020		483
Prior		2,467
Total loans		4,389
Grade 2 [Member] \| Commercial and Industrial [Member]
Financing Receivable Impaired [Line Items]
2023		708
2022		8,029
2021		253
2020		217
Prior		3,842
Revolving Loans		2,438
Total loans		15,487
Grade 2 [Member] \| Consumer and Other [Member]
Financing Receivable Impaired [Line Items]
2023		12,584
2022		14,202
Prior		2,009
Revolving Loans		7
Total loans		28,802
Grade 3 [Member]
Financing Receivable Impaired [Line Items]
2023		3,161,579
2022		4,573,618
2021		3,638,787
2020		1,907,947
2019		869,679
Prior		2,513,574
Revolving Loans		1,506,330
Revolving Loans Converted to Term Loans		9,589
Total loans		18,181,103
Grade 3 [Member] \| Warehouse Purchase Program [Member]
Financing Receivable Impaired [Line Items]
2023		912,327
Total loans		912,327
Grade 3 [Member] \| Real Estate [Member] \| Construction, Land Development and Other Land Loans [Member]
Financing Receivable Impaired [Line Items]
2023		413,440
2022		1,103,554
2021		495,407
2020		210,484
2019		21,398
Prior		171,312
Revolving Loans		201,230
Revolving Loans Converted to Term Loans		7,015
Total loans		2,623,840
Grade 3 [Member] \| Real Estate [Member] \| Agriculture [Member]
Financing Receivable Impaired [Line Items]
2023		128,543
2022		193,029
2021		87,352
2020		47,367
2019		37,641
Prior		101,562
Revolving Loans		82,906
Revolving Loans Converted to Term Loans		95
Total loans		678,495
Grade 3 [Member] \| Real Estate [Member] \| 1-4 Family [Member]
Financing Receivable Impaired [Line Items]
2023		1,066,962
2022		2,011,417
2021		2,165,072
2020		1,065,471
2019		436,951
Prior		991,862
Revolving Loans		93,437
Revolving Loans Converted to Term Loans		1,463
Total loans		7,832,635
Grade 3 [Member] \| Real Estate [Member] \| Commercial Real Estate (Includes Multi-Family Residential) [Member]
Financing Receivable Impaired [Line Items]
2023		377,792
2022		940,534
2021		685,352
2020		487,881
2019		318,912
Prior		1,084,441
Revolving Loans		85,263
Revolving Loans Converted to Term Loans		240
Total loans		3,980,415
Grade 3 [Member] \| Commercial and Industrial [Member]
Financing Receivable Impaired [Line Items]
2023		200,642
2022		281,096
2021		177,474
2020		68,507
2019		43,171
Prior		152,826
Revolving Loans		994,460
Revolving Loans Converted to Term Loans		684
Total loans		1,918,860
Grade 3 [Member] \| Consumer and Other [Member]
Financing Receivable Impaired [Line Items]
2023		61,873
2022		43,988
2021		28,130
2020		28,237
2019		11,606
Prior		11,571
Revolving Loans		49,034
Revolving Loans Converted to Term Loans		92
Total loans		234,531
Grade 4 [Member]
Financing Receivable Impaired [Line Items]
2023		165,437
2022		306,868
2021		330,777
2020		238,993
2019		144,799
Prior		706,945
Revolving Loans		234,060
Revolving Loans Converted to Term Loans		2,613
Grade 4 [Member] \| Real Estate [Member] \| Construction, Land Development and Other Land Loans [Member]
Financing Receivable Impaired [Line Items]
2023		40,692
2022		98,550
2021		94,091
2020		35,723
2019		2,396
Prior		11,667
Revolving Loans		5,467
Total loans		288,586
Grade 4 [Member] \| Real Estate [Member] \| Agriculture [Member]
Financing Receivable Impaired [Line Items]
2023		11,650
2022		20,065
2021		24,273
2020		5,945
2019		13,627
Prior		51,076
Revolving Loans		3,191
Revolving Loans Converted to Term Loans		1,008
Total loans		129,827
Grade 4 [Member] \| Real Estate [Member] \| 1-4 Family [Member]
Financing Receivable Impaired [Line Items]
2023		9,971
2022		16,900
2021		19,557
2020		5,395
2019		451
Prior		7,955
Revolving Loans		22,387
Total loans		83,624
Grade 4 [Member] \| Real Estate [Member] \| Commercial Real Estate (Includes Multi-Family Residential) [Member]
Financing Receivable Impaired [Line Items]
2023		32,814
2022		150,750
2021		175,683
2020		179,686
2019		104,998
Prior		546,811
Revolving Loans		14,942
Revolving Loans Converted to Term Loans		1,127
Total loans		1,206,811
Grade 4 [Member] \| Commercial and Industrial [Member]
Financing Receivable Impaired [Line Items]
2023		68,384
2022		20,313
2021		15,982
2020		11,176
2019		22,026
Prior		88,864
Revolving Loans		184,842
Revolving Loans Converted to Term Loans		478
Total loans		412,065
Grade 4 [Member] \| Consumer and Other [Member]
Financing Receivable Impaired [Line Items]
2023		1,926
2022		290
2021		1,191
2020		1,068
2019		1,301
Prior		572
Revolving Loans		3,231
Total loans		9,579
Grade 5 [Member]
Financing Receivable Impaired [Line Items]
2023		3,252
2022		23,225
2021		6,948
2020		1,182
2019		34,515
Prior		50,697
Revolving Loans		3,725
Revolving Loans Converted to Term Loans		6,475
Total loans		130,019
Grade 5 [Member] \| Commercial Real Estate (Includes Multi-Family Residential) [Member]
Financing Receivable Impaired [Line Items]
2019		15,938
Total loans		119,633
Grade 5 [Member] \| Real Estate [Member] \| Construction, Land Development and Other Land Loans [Member]
Financing Receivable Impaired [Line Items]
2021		4,399
2019		18,678
Prior		629
Revolving Loans		915
Total loans		24,621
Grade 5 [Member] \| Real Estate [Member] \| Agriculture [Member]
Financing Receivable Impaired [Line Items]
2023		70
2022		794
2021		286
2019		441
Prior		1,466
Total loans		3,057
Grade 5 [Member] \| Real Estate [Member] \| 1-4 Family [Member]
Financing Receivable Impaired [Line Items]
2022		58
2020		122
Prior		2,496
Total loans		2,676
Grade 5 [Member] \| Real Estate [Member] \| Commercial Real Estate (Includes Multi-Family Residential) [Member]
Financing Receivable Impaired [Line Items]
2019		14,988
Prior		45,636
Revolving Loans		1,555
Total loans		62,179
Grade 5 [Member] \| Commercial and Industrial [Member]
Financing Receivable Impaired [Line Items]
2023		3,182
2022		22,373
2021		2,263
2020		1,060
2019		408
Prior		470
Revolving Loans		1,255
Revolving Loans Converted to Term Loans		6,475
Total loans		37,486
Grade 6 [Member]
Financing Receivable Impaired [Line Items]
2023		42
2022		1,423
2021		8,380
2020		13,550
2019		17,492
Prior		93,623
Revolving Loans		4,671
Revolving Loans Converted to Term Loans		111
Total loans		139,292
Grade 6 [Member] \| Commercial Real Estate (Includes Multi-Family Residential) [Member]
Financing Receivable Impaired [Line Items]
2022		934
2021		1,548
2020		11,946
Prior		89,267
Grade 6 [Member] \| Real Estate [Member] \| Construction, Land Development and Other Land Loans [Member]
Financing Receivable Impaired [Line Items]
2021		6,217
2020		191
2019		230
Prior		1,185
Total loans		7,823
Grade 6 [Member] \| Real Estate [Member] \| Agriculture [Member]
Financing Receivable Impaired [Line Items]
2023
2022
2021		116
Prior		478
Total loans		594
Grade 6 [Member] \| Real Estate [Member] \| 1-4 Family [Member]
Financing Receivable Impaired [Line Items]
2021		224
2020		15
2019		244
Prior		1,582
Total loans		2,065
Grade 6 [Member] \| Commercial and Industrial [Member]
Financing Receivable Impaired [Line Items]
2023		42
2022		489
2021		275
2020		1,398
2019		1,080
Prior		1,111
Revolving Loans		4,671
Revolving Loans Converted to Term Loans		111
Total loans		9,177
Grade 7 [Member]
Financing Receivable Impaired [Line Items]
2023		4,956
2022		21,099
2021		8,776
2020		6,861
2019		5,472
Prior		11,464
Revolving Loans		1,101
Total loans		59,729
Grade 7 [Member] \| Real Estate [Member] \| Construction, Land Development and Other Land Loans [Member]
Financing Receivable Impaired [Line Items]
2022		928
2021		1,647
2020		3,318
Prior		1,587
Revolving Loans		266
Total loans		7,746
Grade 7 [Member] \| Real Estate [Member] \| Agriculture [Member]
Financing Receivable Impaired [Line Items]
2021		1,334
2019		15
Prior		162
Total loans		1,511
Grade 7 [Member] \| Real Estate [Member] \| 1-4 Family [Member]
Financing Receivable Impaired [Line Items]
2023		244
2022		3,984
2021		5,244
2020		3,528
2019		1,904
Prior		8,459
Revolving Loans		76
Total loans		23,439
Grade 7 [Member] \| Real Estate [Member] \| Commercial Real Estate (Includes Multi-Family Residential) [Member]
Financing Receivable Impaired [Line Items]
2022		827
2021		365
2019		3,473
Prior		563
Total loans		5,228
Grade 7 [Member] \| Commercial and Industrial [Member]
Financing Receivable Impaired [Line Items]
2023		4,712
2022		15,360
2021		186
2019		77
Prior		693
Revolving Loans		759
Total loans		21,787
Grade 7 [Member] \| Consumer and Other [Member]
Financing Receivable Impaired [Line Items]
2020		15
2019		3
Total loans		$ 18

[1] Includes $ 10.2 million and $ 554 thousand of residential mortgage loans held for sale at September 30, 2023 and December 31, 2022 , respectively.

Loans and Allowance for Cred_13

Loans and Allowance for Credit Losses - Risk Grade by Category of Loan and Year of Origination/Renewal (Parenthetical) (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Financing Receivable Impaired [Line Items]
Loans held for sale	$ 10,187	$ 554
Residential Mortgage Loans [Member]
Financing Receivable Impaired [Line Items]
Loans held for sale	$ 10,187	$ 554

Loans and Allowance for Cred_14

Loans and Allowance for Credit Losses - Allowance for Credit Losses on Loans by Category of Loan (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for credit losses, beginning balance	$ 345,209,000	$ 283,959,000	$ 281,576,000	$ 286,380,000
Initial allowance on loans purchased with credit deterioration	9,694,000		76,793,000
Provision for credit losses		0	11,984,000	0
Charge-offs	(4,115,000)	(2,574,000)	(23,139,000)	(6,642,000)
Recoveries	707,000	794,000	4,281,000	2,441,000
Net (charge-offs) recoveries	(3,408,000)	(1,780,000)	(18,858,000)	(4,201,000)
Allowance for credit losses, ending balance	351,495,000	282,179,000	351,495,000	282,179,000
Agriculture [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for credit losses, beginning balance	11,254,000	8,338,000	7,699,000	7,759,000
Initial allowance on loans purchased with credit deterioration			2,914,000
Provision for credit losses	149,000	(377,000)	706,000	90,000
Charge-offs		(119,000)	(113,000)	(274,000)
Recoveries			197,000	267,000
Net (charge-offs) recoveries		119,000	(84,000)	7,000
Allowance for credit losses, ending balance	11,403,000	7,842,000	11,403,000	7,842,000
Real Estate [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for credit losses, beginning balance			281,576,000
Allowance for credit losses, ending balance	351,495,000		351,495,000
Real Estate [Member] \| Construction, Land Development and Other Land Loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for credit losses, beginning balance	91,858,000	63,729,000	78,853,000	58,897,000
Initial allowance on loans purchased with credit deterioration	1,641,000		16,878,000
Provision for credit losses	1,437,000	2,454,000	(758,000)	7,711,000
Charge-offs			(77,000)	(435,000)
Recoveries	5,000	4,000	45,000	14,000
Net (charge-offs) recoveries	5,000	4,000	(32,000)	(421,000)
Allowance for credit losses, ending balance	94,941,000	66,187,000	94,941,000	66,187,000
Real Estate [Member] \| 1-4 Family [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for credit losses, beginning balance	67,722,000	60,096,000	60,795,000	56,710,000
Initial allowance on loans purchased with credit deterioration			1,590,000
Provision for credit losses	3,932,000	1,213,000	9,059,000	2,228,000
Charge-offs	(20,000)	(59,000)	(121,000)	(159,000)
Recoveries	98,000	261,000	409,000	306,000
Net (charge-offs) recoveries	78,000	202,000	288,000	(147,000)
Allowance for credit losses, ending balance	71,732,000	59,085,000	71,732,000	59,085,000
Real Estate [Member] \| Commercial Real Estate (Includes Multi-Family Residential) [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for credit losses, beginning balance	86,765,000	70,011,000	66,272,000	75,005,000
Initial allowance on loans purchased with credit deterioration	4,290,000		25,292,000
Provision for credit losses	4,554,000	2,098,000	9,893,000	(7,063,000)
Charge-offs	(584,000)	(757,000)	(15,559,000)	(796,000)
Recoveries	14,000		33,000	10,000
Net (charge-offs) recoveries	(570,000)	(757,000)	(15,526,000)	(786,000)
Allowance for credit losses, ending balance	85,931,000	67,156,000	85,931,000	67,156,000
Commercial and Industrial [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for credit losses, beginning balance	81,970,000	75,694,000	62,319,000	80,412,000
Initial allowance on loans purchased with credit deterioration	3,763,000		30,095,000
Provision for credit losses	(2,455,000)	(37,000)	(10,448,000)	(4,938,000)
Charge-offs	(1,961,000)	(253,000)	(3,203,000)	(917,000)
Recoveries	367,000	268,000	2,921,000	1,115,000
Net (charge-offs) recoveries	(1,594,000)	15,000	(282,000)	198,000
Allowance for credit losses, ending balance	81,684,000	75,672,000	81,684,000	75,672,000
Consumer and Other [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for credit losses, beginning balance	5,640,000	6,091,000	5,638,000	7,597,000
Initial allowance on loans purchased with credit deterioration			24,000
Provision for credit losses	1,491,000	1,271,000	3,532,000	1,972,000
Charge-offs	(1,550,000)	(1,386,000)	(4,066,000)	(4,061,000)
Recoveries	223,000	261,000	676,000	729,000
Net (charge-offs) recoveries	(1,327,000)	(1,125,000)	(3,390,000)	(3,332,000)
Allowance for credit losses, ending balance	$ 5,804,000	$ 6,237,000	$ 5,804,000	$ 6,237,000

Loans and Allowance for Cred_15

Loans and Allowance for Credit Losses - Rollforward of Allowance for Credit Losses on Off-Balance Sheet Credit Exposures (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2023 USD ($)
Off-Balance-Sheet, Credit Loss, Liability [Abstract]
Allowance for credit losses on off-balance sheet credit exposures, Beginning Balance	$ 29,947
Provision for credit losses on off-balance sheet credit exposures	6,556
Allowance for credit losses on off-balance sheet credit exposures, Ending Balance	$ 36,503

Loans and Allowance for Cred_16

Loans and Allowance for Credit Losses - Schedule of Amortized Cost of Loans Experiencing Financial Difficulty and Modified (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2023
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost	$ 12,980	$ 20,620
Percentage of total loans held for investment	0.05%	0.10%
Payment Delay [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost		$ 1,294
Term Extension [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost	$ 6,058	12,112
Interest Rate Reduction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost	6,922	7,214
Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost	$ 6,922	$ 8,216
Percentage of total loans held for investment	0.03%	0.04%
Real Estate [Member] \| Payment Delay [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost		$ 1,294
Real Estate [Member] \| Interest Rate Reduction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost	$ 6,922	6,922
Commercial and Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost	$ 5,639	$ 5,931
Percentage of total loans held for investment	0.03%	0.03%
Commercial and Industrial [Member] \| Term Extension [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost	$ 5,639	$ 5,639
Commercial and Industrial [Member] \| Interest Rate Reduction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost		292
Construction, Land Development and Other Land Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost		$ 6,054
Percentage of total loans held for investment	0%	0.03%
Construction, Land Development and Other Land Loans [Member] \| Term Extension [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost		$ 6,054
Agriculture [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost	$ 419	$ 419
Percentage of total loans held for investment	0%	0%
Agriculture [Member] \| Term Extension [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost	$ 419	$ 419

Loans and Allowance for Cred_17

Loans and Allowance for Credit Losses - Schedule of Loan Modifications (Details)	3 Months Ended	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2023
Commercial and Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial Effect on Term Extension	Short-term extension	Short-term extension
Financial Effect on Interest Rate Reduction		Reduced contractual interest rate
Construction, Land Development and Other Land Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial Effect on Term Extension		Short-term extension
Agriculture [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial Effect on Term Extension	Short-term extension	Short-term extension
Commercial Real Estate (Includes Multi-Family Residential) [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial Effect on Payment Delay		Short-term principal deferral
Financial Effect on Interest Rate Reduction	Reduced contractual interest rate	Reduced contractual interest rate

Fair Value - Fair Value Assets

Fair Value - Fair Value Assets and Liabilities Measured on Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Available for sale securities:
Available for sale securities, at fair value	$ 446,165	$ 456,502
Corporate Debt Securities [Member]
Available for sale securities:
Available for sale securities, at fair value	21,485
Fair Value, Measurements, Recurring [Member]
Available for sale securities:
Available for sale securities, at fair value	446,165	456,502
Fair Value, Measurements, Recurring [Member] \| Loan Customer Counterparty [Member]
Derivative financial instruments:
Derivative financial instruments, liabilities at fair value	5,699	5,522
Fair Value, Measurements, Recurring [Member] \| Financial Institution Counterparty [Member]
Derivative financial instruments:
Derivative financial instruments, assets at fair value	5,660	5,522
Fair Value, Measurements, Recurring [Member] \| Interest Rate Lock Commitments [Member]
Derivative financial instruments:
Derivative financial instruments, assets at fair value	302	94
Derivative financial instruments:
Derivative financial instruments, liabilities at fair value	35	6
Fair Value, Measurements, Recurring [Member] \| Forward Mortgage-Backed Securities Trades [Member]
Derivative financial instruments:
Derivative financial instruments, assets at fair value	240	31
Derivative financial instruments:
Derivative financial instruments, liabilities at fair value	3
Fair Value, Measurements, Recurring [Member] \| Corporate Debt Securities [Member]
Available for sale securities:
Available for sale securities, at fair value	21,485
Fair Value, Measurements, Recurring [Member] \| Level 2 [Member]
Available for sale securities:
Available for sale securities, at fair value	446,165	456,502
Fair Value, Measurements, Recurring [Member] \| Level 2 [Member] \| Loan Customer Counterparty [Member]
Derivative financial instruments:
Derivative financial instruments, liabilities at fair value	5,699	5,522
Fair Value, Measurements, Recurring [Member] \| Level 2 [Member] \| Financial Institution Counterparty [Member]
Derivative financial instruments:
Derivative financial instruments, assets at fair value	5,660	5,522
Fair Value, Measurements, Recurring [Member] \| Level 2 [Member] \| Interest Rate Lock Commitments [Member]
Derivative financial instruments:
Derivative financial instruments, assets at fair value	302	94
Derivative financial instruments:
Derivative financial instruments, liabilities at fair value	35	6
Fair Value, Measurements, Recurring [Member] \| Level 2 [Member] \| Forward Mortgage-Backed Securities Trades [Member]
Derivative financial instruments:
Derivative financial instruments, assets at fair value	240	31
Derivative financial instruments:
Derivative financial instruments, liabilities at fair value	3
Fair Value, Measurements, Recurring [Member] \| Level 2 [Member] \| Corporate Debt Securities [Member]
Available for sale securities:
Available for sale securities, at fair value	21,485
Fair Value, Measurements, Recurring [Member] \| Collateralized Mortgage Obligations [Member]
Available for sale securities:
Available for sale securities, at fair value	327,524	357,402
Fair Value, Measurements, Recurring [Member] \| Collateralized Mortgage Obligations [Member] \| Level 2 [Member]
Available for sale securities:
Available for sale securities, at fair value	327,524	357,402
Fair Value, Measurements, Recurring [Member] \| Mortgage-backed Securities [Member]
Available for sale securities:
Available for sale securities, at fair value	97,156	99,100
Fair Value, Measurements, Recurring [Member] \| Mortgage-backed Securities [Member] \| Level 2 [Member]
Available for sale securities:
Available for sale securities, at fair value	$ 97,156	$ 99,100

Fair Value - Additional Informa

Fair Value - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2023
Fair Value Disclosures [Abstract]
Other real estate, additions	$ 8.6	$ 10.2
Real estate owned outstanding	8.2	8.4
Additions to impaired loans	13.7	36.3
Impaired loans outstanding	$ 13.7	$ 20.3

Fair Value - Summary of Carryin

Fair Value - Summary of Carrying and Fair Value Information of Financial Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Assets
Cash and due from banks	$ 512,239	$ 423,832
Federal funds sold	234	301
Held to maturity securities	10,834,219	12,387,125
Loans held for sale	10,187	554
Loans held for investment	20,510,199	18,098,653
Other real estate owned	9,320	1,963
Liabilities
Noninterest-bearing	10,281,893	10,915,448
Interest-bearing	17,030,907	17,618,083
Other borrowings	4,250,000	1,850,000
Securities sold under repurchase agreements	300,714	428,134
Carrying Amount [Member]
Assets
Cash and due from banks	512,239	423,832
Federal funds sold	234	301
Held to maturity securities	12,746,577	14,019,503
Loans held for sale	10,187	554
Loans held for investment, net of allowance	20,158,704	17,817,077
Loans held for investment	912,327	740,620
Other real estate owned	9,320	1,963
Liabilities
Noninterest-bearing	10,281,893	10,915,448
Interest-bearing	17,030,907	17,618,083
Other borrowings	4,250,000	1,850,000
Securities sold under repurchase agreements	300,714	428,134
Estimated Fair Value [Member]
Assets
Cash and due from banks	512,239	423,832
Federal funds sold	234	301
Held to maturity securities	10,834,219	12,387,125
Loans held for sale	10,187	554
Loans held for investment, net of allowance	19,017,863	17,550,309
Loans held for investment	912,327	740,620
Other real estate owned	9,320	1,963
Liabilities
Noninterest-bearing	10,281,893	10,915,448
Interest-bearing	16,984,181	17,563,711
Other borrowings	4,179,418	1,850,000
Securities sold under repurchase agreements	300,662	428,061
Estimated Fair Value [Member] \| Level 1 [Member]
Assets
Cash and due from banks	512,239	423,832
Federal funds sold	234	301
Estimated Fair Value [Member] \| Level 2 [Member]
Assets
Held to maturity securities	10,834,219	12,387,125
Loans held for sale	10,187	554
Loans held for investment	912,327	740,620
Other real estate owned	9,320	1,963
Liabilities
Noninterest-bearing	10,281,893	10,915,448
Interest-bearing	16,984,181	17,563,711
Other borrowings	4,179,418	1,850,000
Securities sold under repurchase agreements	300,662	428,061
Estimated Fair Value [Member] \| Level 3 [Member]
Assets
Loans held for investment, net of allowance	$ 19,017,863	$ 17,550,309

Goodwill and Core Deposit Int_3

Goodwill and Core Deposit Intangibles - Goodwill and Core Deposit Intangibles (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill, Beginning balance			$ 3,231,636	$ 3,231,636	$ 3,231,636
Goodwill, First Bancshares Merger			164,823
Goodwill, Ending balance	$ 3,396,459		3,396,459		3,231,636
Core Deposit Intangibles, Beginning balance			51,348	61,684	61,684
Core Deposit Intangibles, Amortization	(3,576)	$ (2,577)	(9,117)	$ (7,778)	(10,336)
Core Deposit Intangibles, First Bancshares Merger			25,322
Core Deposit Intangibles, Ending balance	$ 67,553		$ 67,553		$ 51,348

Goodwill and Core Deposit Int_4

Goodwill and Core Deposit Intangibles - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Schedule Of Intangible Assets And Goodwill [Line Items]
Impairment recorded on goodwill and core deposit intangibles			$ 0
Amortization expense related to intangible assets	$ 3,576,000	$ 2,577,000	$ 9,117,000	$ 7,778,000	$ 10,336,000
Minimum [Member]
Schedule Of Intangible Assets And Goodwill [Line Items]
Finite-lived intangible assets, useful life	10 years		10 years
Maximum [Member]
Schedule Of Intangible Assets And Goodwill [Line Items]
Finite-lived intangible assets, useful life	15 years		15 years

Goodwill and Core Deposit Int_5

Goodwill and Core Deposit Intangibles - Estimated Aggregate Future Amortization Expense for Core Deposit Intangibles (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022	Dec. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Remaining 2023	$ 3,559
2024	12,813
2025	11,410
2026	10,376
2027	9,288
Thereafter	20,107
Total	$ 67,553	$ 51,348	$ 61,684

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023 USD ($) Plan shares	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($) Plan shares	Sep. 30, 2022 USD ($)	Mar. 03, 2020 shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of stock-based employee compensation plans \| Plan	1		1
Total unrecognized compensation expense related to stock-based compensation arrangements \| $	$ 9.9		$ 9.9
Weighted-average period of cost expected to be recognized			1 year 11 months 26 days
Number of shares outstanding	0		0
Restricted Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense \| $	$ 3.1	$ 2.9	$ 9.1	$ 8.5
2020 Stock Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common shares authorized for issuance					2,500,000
2020 Stock Incentive Plan [Member] \| Restricted Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share issued			505,593
Shares vested			65,932

Contractual Obligations and O_3

Contractual Obligations and Off-Balance Sheet Items - Summary of Future Cash Payments Associated with Contractual Obligations Pursuant to Subordinated Debentures, Federal Reserve's Bank Term Funding Program and Federal Home Loan Bank Advances (Details) - Guarantee Obligations [Member] $ in Thousands	Sep. 30, 2023 USD ($)
Contractual Obligations And Off Balance Sheet Items [Line Items]
1 year or less	$ 2,971,225
More than 1 year but less than 3 years	1,088,124
3 years or more but less than 5 years	307,229
5 years or more	1,898,943
Total	6,265,521
Payment Guarantee [Member]
Contractual Obligations And Off Balance Sheet Items [Line Items]
1 year or less	4,352,848
Total	4,352,848
Payment Guarantee [Member] \| Bank Term Funding Program [Member]
Contractual Obligations And Off Balance Sheet Items [Line Items]
1 year or less	3,102,848
Total	3,102,848
Payment Guarantee [Member] \| Federal Home Loan Bank Advances [Member]
Contractual Obligations And Off Balance Sheet Items [Line Items]
1 year or less	1,250,000
Total	$ 1,250,000

Contractual Obligations and O_4

Contractual Obligations and Off-Balance Sheet Items - Additional Information (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($) SubleaseArrangement	Sep. 30, 2022 USD ($)	Jun. 30, 2023 USD ($)	Dec. 31, 2022 USD ($)	Jun. 30, 2022 USD ($)	Dec. 31, 2021 USD ($)
Contractual Obligations And Off Balance Sheet Items [Line Items]
Operating lease, right-of-use asset	$ 38,600		$ 38,600
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Other assets		Other assets
Operating Lease, Liability, Statement of Financial Position [Extensible Enumeration]	Other liabilities		Other liabilities
Number of sublease arrangement \| SubleaseArrangement			1
Sublease income	$ 816	$ 807	$ 2,300	$ 2,400
Operating lease, weighted average remaining lease term	4 years 2 months 12 days		4 years 2 months 12 days
Operating lease, weighted average discount rate, percent	2%		2%
Operating lease, payments	$ 3,100	2,700	$ 9,000	8,100
Right-of-Use asset obtained in exchange for operating lease liability			3,200
Allowance for credit losses on off-balance sheet credit exposures	36,503	$ 29,947	36,503	$ 29,947	$ 36,503	$ 29,947	$ 29,947	$ 29,947
Merger [Member]
Contractual Obligations And Off Balance Sheet Items [Line Items]
Right-of-Use asset obtained in exchange for operating lease liability			2,700
Bank Term Funding Program [Member]
Contractual Obligations And Off Balance Sheet Items [Line Items]
Interest payable	$ 102,800		$ 102,800
Minimum [Member]
Contractual Obligations And Off Balance Sheet Items [Line Items]
Lessee operating lease remaining lease term	1 year		1 year
Maximum [Member]
Contractual Obligations And Off Balance Sheet Items [Line Items]
Lessee operating lease remaining lease term	15 years		15 years

Contractual Obligations and O_5

Contractual Obligations and Off-Balance Sheet Items - Future Undiscounted Cash Payments Associated with its Operating Leases (Details) $ in Thousands	Sep. 30, 2023 USD ($)
Leases [Abstract]
Remaining 2023	$ 2,696
2024	10,301
2025	9,737
2026	8,592
2027	5,569
2028	2,588
Thereafter	5,283
Total undiscounted lease payments	$ 44,766

Contractual Obligations and O_6

Contractual Obligations and Off-Balance Sheet Items - Summary of Commitments Associated with Outstanding Standby Letters of Credit and Commitments to Extend Credit (Details) - Guarantee Obligations [Member] $ in Thousands	Sep. 30, 2023 USD ($)
Contractual Obligations And Off Balance Sheet Items [Line Items]
1 year or less	$ 2,971,225
More than 1 year but less than 3 years	1,088,124
3 years or more but less than 5 years	307,229
5 years or more	1,898,943
Total	6,265,521
Standby Letters of Credit [Member]
Contractual Obligations And Off Balance Sheet Items [Line Items]
1 year or less	72,215
More than 1 year but less than 3 years	7,456
3 years or more but less than 5 years	1,100
5 years or more	26
Total	80,797
Unused capacity on Warehouse Purchase Program loans [Member]
Contractual Obligations And Off Balance Sheet Items [Line Items]
1 year or less	1,170,673
Total	1,170,673
Commitments to Extend Credit [Member]
Contractual Obligations And Off Balance Sheet Items [Line Items]
1 year or less	1,728,337
More than 1 year but less than 3 years	1,080,668
3 years or more but less than 5 years	306,129
5 years or more	1,898,917
Total	$ 5,014,051

Other Comprehensive Income - Ta

Other Comprehensive Income - Tax Effects Allocated to Each Component of Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Equity [Abstract]
Change in unrealized gain (loss) during period, before tax amount	$ 951	$ (1,813)	$ 1,953	$ (2,587)
Change in unrealized gain (loss) during period, tax effect	(200)	380	(410)	543
Change in unrealized gain (loss) during period, net of tax amount	751	(1,433)	1,543	(2,044)
Total securities available for sale, before tax amount	951	(1,813)	1,953	(2,587)
Total securities available for sale, tax effect	(200)	380	(410)	543
Total securities available for sale, net of tax amount	751	(1,433)	1,543	(2,044)
Total other comprehensive income (loss), before tax amount	951	(1,813)	1,953	(2,587)
Total other comprehensive income (loss), tax effect	(200)	380	(410)	543
Other comprehensive income (loss), net of tax	$ 751	$ (1,433)	$ 1,543	$ (2,044)

Other Comprehensive Income - Ac

Other Comprehensive Income - Activity in Accumulated Other Comprehensive Income (Loss) Associated with Securities Available for Sale, Net of Tax (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Beginning balance, accumulated other comprehensive income			$ (3,473)	$ 1,809
Other comprehensive income (loss)	$ 751	$ (1,433)	1,543	(2,044)
Ending balance, accumulated other comprehensive income	(1,930)	(235)	(1,930)	(235)
Accumulated Net Investment Gain (Loss) Attributable to Parent [Member]
Beginning balance, accumulated other comprehensive income			(3,473)	1,809
Other comprehensive income (loss)			1,543	(2,044)
Ending balance, accumulated other comprehensive income	$ (1,930)	$ (235)	$ (1,930)	$ (235)

Derivative Financial Instrume_3

Derivative Financial Instruments - Schedule of Notional Balances and Fair Value of Derivative Positions (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Interest Rate Lock Commitments [Member]
Derivatives Fair Value [Line Items]
Outstanding Notional Balance	$ 19,296	$ 4,599
Derivative financial instruments, assets at fair value	302	94
Derivative financial instruments, liabilities at fair value	35	6
Forward Mortgage-Backed Securities Trades [Member]
Derivatives Fair Value [Line Items]
Outstanding Notional Balance	28,250	5,250
Derivative financial instruments, assets at fair value	240	31
Derivative financial instruments, liabilities at fair value	3
Commercial Loan Interest Rate Swaps and Caps [Member] \| Loan Customer Counterparty [Member]
Derivatives Fair Value [Line Items]
Outstanding Notional Balance	67,535	93,214
Derivative financial instruments, liabilities at fair value	5,699	5,522
Commercial Loan Interest Rate Swaps and Caps [Member] \| Financial Institution Counterparty [Member]
Derivatives Fair Value [Line Items]
Outstanding Notional Balance	67,535	93,214
Derivative financial instruments, assets at fair value	$ 5,660	$ 5,522

Derivative Financial Instrume_4

Derivative Financial Instruments - Schedule of Weighted Average Received and Paid Interest Rates for Interest Rate Swaps Outstanding (Details) - Commercial Loan Interest Rate Swaps and Caps [Member] - Loan Customer Counterparty [Member]	Sep. 30, 2023	Dec. 31, 2022
Derivative [Line Items]
Weighted-Average Interest Rate Received	0.0307	0.0305
Weighted-Average Interest Rate Paid	0.0679	0.0518

Derivative Financial Instrume_5

Derivative Financial Instruments - Additional Information (Details) - Interest Rate Swap [Member] - USD ($)	Sep. 30, 2023	Dec. 31, 2022
Derivative [Line Items]
Credit exposure	$ 5,700,000	$ 5,500,000
Cash collateral pledged	0	$ 0
Financial Institution Counterparty [Member]
Derivative [Line Items]
Credit exposure	$ 0

Derivative Financial Instrume_6

Derivative Financial Instruments - Schedule of Income (Loss) from Derivatives (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Interest Rate Lock Commitments [Member]
Derivative Instruments Gain Loss [Line Items]
Derivatives not designated as hedging instruments	$ (11)	$ 264	$ 103	$ (269)
Forward Mortgage-Backed Securities Trades [Member]
Derivative Instruments Gain Loss [Line Items]
Derivatives not designated as hedging instruments	$ 510	$ 343	$ 668	$ 822

Acquisitions - Additional Infor

Acquisitions - Additional Information (Details)			3 Months Ended			9 Months Ended
Acquisitions - Additional Information (Details)	May 31, 2023 Office	Oct. 11, 2022 USD ($) Office shares	Sep. 30, 2023 USD ($) $ / shares	Jun. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($) $ / shares shares	Sep. 30, 2022 USD ($)	Mar. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Oct. 07, 2022 $ / shares	Dec. 31, 2021 USD ($)
Business Acquisition [Line Items]
Goodwill			$ 3,396,459,000			$ 3,396,459,000			$ 3,231,636,000		$ 3,231,636,000
Core deposit intangibles			67,553,000			67,553,000			51,348,000		$ 61,684,000
Total assets			39,295,684,000			39,295,684,000			37,689,829,000
Loans			21,081,218,000			21,081,218,000			18,558,251,000
Total deposits			27,312,800,000			27,312,800,000			$ 28,533,531,000
Merger related expenses			1,104,000			14,855,000
Provision for credit losses						18,540,000
Provision for credit losses on loans					$ 0	11,984,000	$ 0
Provision for credit losses on off-balance sheet credit exposures						$ 6,556,000
First Bancshares of Texas, Inc. [Member]
Business Acquisition [Line Items]
Business acquisition, equity interest issued or issuable, number of shares \| shares						3,583,370
Payments to acquire businesses in cash						$ 91,500,000
Goodwill			$ 164,800,000			$ 164,800,000
Total assets								$ 2,140,000,000
Loans								1,650,000,000
Total deposits								$ 1,710,000,000
Business acquisition, closing share price \| $ / shares			$ 62.62			$ 62.62
Provision for credit losses on loans				$ 12,000,000
First Bancshares of Texas, Inc. [Member] \| West, North and Central Texas [Member]
Business Acquisition [Line Items]
Number of full-service banking offices \| Office	16
Lone Star State Bancshares Inc [Member]
Business Acquisition [Line Items]
Business acquisition, equity interest issued or issuable, number of shares \| shares		2,376,182
Payments to acquire businesses in cash		$ 64,100,000
Total assets			$ 1,270,000,000			$ 1,270,000,000
Loans			1,100,000,000			1,100,000,000
Total deposits			$ 1,110,000,000			$ 1,110,000,000
Business acquisition, closing share price \| $ / shares										$ 69.27
Total consideration		$ 228,700,000
Lone Star State Bancshares Inc [Member] \| West Texas [Member]
Business Acquisition [Line Items]
Number of banking offices \| Office		5