Atmos Energy (ATO) 10-Q2 Aug 232023 Q3 Quarterly reportFinancial data

Company Profile

Cover Page

Cover Page - shares	9 Months Ended
Cover Page - shares	Jun. 30, 2023	Jul. 28, 2023
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2023
Document Transition Report	false
Entity File Number	1-10042
Entity Registrant Name	Atmos Energy Corp
Entity Incorporation, State or Country Code	TX
Entity Tax Identification Number	75-1743247
Entity Address, Address Line One	1800 Three Lincoln Centre
Entity Address, Address Line Two	5430 LBJ Freeway
Entity Address, City or Town	Dallas
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	75240
City Area Code	972
Local Phone Number	934-9227
Title of 12(b) Security	Common stock
Trading Symbol	ATO
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding (in shares)		148,462,481
Entity Central Index Key	0000731802
Current Fiscal Year End Date	--09-30
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q3
Amendment Flag	false

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2023	Sep. 30, 2022
ASSETS
Property, plant and equipment	$ 22,224,360	$ 20,238,139
Less accumulated depreciation and amortization	3,206,019	2,997,900
Net property, plant and equipment	19,018,341	17,240,239
Current assets
Cash and cash equivalents	56,237	51,554
Restricted cash and cash equivalents	1,876	0
Cash and cash equivalents and restricted cash and cash equivalents	58,113	51,554
Accounts receivable, net (See Note 5)	330,827	363,708
Gas stored underground	211,041	357,941
Other current assets (See Note 8)	288,945	2,274,490
Total current assets	888,926	3,047,693
Securitized intangible asset, net (See Note 9)	93,600	0
Goodwill	731,257	731,257
Deferred charges and other assets (See Note 8)	1,039,405	1,173,800
Total assets	21,771,529	22,192,989
Shareholders’ equity
Common stock, no par value (stated at $0.005 per share); 200,000,000 shares authorized; issued and outstanding: June 30, 2023 — 147,304,538 shares; September 30, 2022 — 140,896,598 shares	737	704
Additional paid-in capital	6,537,820	5,838,118
Accumulated other comprehensive income	404,403	369,112
Retained earnings	3,659,421	3,211,157
Shareholders’ equity	10,602,381	9,419,091
Long-term debt, net	6,553,618	5,760,647
Securitized long-term debt (See Note 9)	89,027	0
Total capitalization	17,245,026	15,179,738
Current liabilities
Accounts payable and accrued liabilities	327,890	496,019
Other current liabilities	698,918	720,157
Short-term debt	0	184,967
Current maturities of long-term debt	1,540	2,201,457
Current maturities of securitized long-term debt (See Note 9)	5,973	0
Total current liabilities	1,034,321	3,602,600
Deferred income taxes	2,205,291	1,999,505
Regulatory excess deferred taxes	277,506	385,213
Regulatory cost of removal obligation	487,996	487,631
Deferred credits and other liabilities	521,389	538,302
Total capitalization and liabilities	$ 21,771,529	$ 22,192,989

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Jun. 30, 2023	Sep. 30, 2022
Statement of Financial Position [Abstract]
Common stock stated value (USD per share)	$ 0.005	$ 0.005
Common stock authorized (in shares)	200,000,000	200,000,000
Common stock issued (in shares)	147,304,538	140,896,598
Common stock outstanding (in shares)	147,304,538	140,896,598

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Operating revenues	$ 662,733	$ 816,429	$ 3,687,715	$ 3,479,034
Purchased gas cost	44,550	249,159	1,449,010	1,491,700
Operation and maintenance expense	195,049	182,325	574,781	504,787
Depreciation and amortization expense	150,726	134,231	445,063	395,461
Taxes, other than income	103,155	96,127	305,784	271,506
Operating income	169,253	154,587	913,077	815,580
Other non-operating income	16,170	13,263	54,767	27,178
Interest charges	31,334	26,190	105,464	74,969
Income before income taxes	154,089	141,660	862,380	767,789
Income tax expense	16,282	13,113	95,042	65,034
Net income	$ 137,807	$ 128,547	$ 767,338	$ 702,755
Basic net income per share (USD per share)	$ 0.94	$ 0.92	$ 5.33	$ 5.13
Diluted net income per share (USD per share)	0.94	0.92	5.33	5.12
Cash dividends per share (USD per share)	$ 0.74	$ 0.68	$ 2.22	$ 2.04
Basic weighted average shares outstanding (in shares)	146,051	139,881	143,938	136,799
Diluted weighted average shares outstanding (in shares)	146,067	140,227	143,998	137,055
Other comprehensive income (loss), net of tax
Net unrealized holding gains (losses) on available-for-sale securities	$ (121)	$ (106)	$ 100	$ (336)
Cash flow hedges:
Amortization and unrealized gains (losses) on interest rate agreements	43,527	159,737	35,191	235,743
Net current-period other comprehensive income (loss)	43,406	159,631	35,291	235,407
Total comprehensive income	181,213	288,178	802,629	938,162
Distribution segment
Operating revenues	615,259	772,497	3,554,389	3,353,800
Pipeline and storage segment
Operating revenues	47,474	43,932	133,326	125,234
Purchased gas cost
Purchased gas cost	44,550	249,159	1,449,010	1,491,700
Operating Segments \| Distribution segment
Operating revenues	616,067	773,311	3,556,703	3,356,279
Purchased gas cost	206,048	390,559	1,896,986	1,881,212
Operation and maintenance expense	138,351	133,654	426,173	378,479
Depreciation and amortization expense	107,809	97,106	319,783	286,515
Taxes, other than income	92,180	85,933	275,002	242,214
Operating income	71,679	66,059	638,759	567,859
Other non-operating income	6,695	6,708	20,934	9,173
Interest charges	16,146	12,341	60,405	36,046
Income before income taxes	62,228	60,426	599,288	540,986
Income tax expense	2,589	3,025	56,707	35,163
Net income	59,639	57,401	542,581	505,823
Operating Segments \| Pipeline and storage segment
Operating revenues	208,225	183,412	579,278	510,077
Purchased gas cost	(194)	(1,347)	(431)	(3,075)
Operation and maintenance expense	56,953	48,912	149,329	127,193
Depreciation and amortization expense	42,917	37,125	125,280	108,946
Taxes, other than income	10,975	10,194	30,782	29,292
Operating income	97,574	88,528	274,318	247,721
Other non-operating income	9,475	6,555	33,833	18,005
Interest charges	15,188	13,849	45,059	38,923
Income before income taxes	91,861	81,234	263,092	226,803
Income tax expense	13,693	10,088	38,335	29,871
Net income	78,168	71,146	224,757	196,932
Operating Segments \| Purchased gas cost \| Distribution segment
Purchased gas cost	206,048	390,559	1,896,986	1,881,212
Operating Segments \| Purchased gas cost \| Pipeline and storage segment
Purchased gas cost	(194)	(1,347)	(431)	(3,075)
Intersegment eliminations
Operating revenues	(161,559)	(140,294)	(448,266)	(387,322)
Purchased gas cost	(161,304)	(140,053)	(447,545)	(386,437)
Operation and maintenance expense	(255)	(241)	(721)	(885)
Depreciation and amortization expense	0	0	0	0
Taxes, other than income	0	0	0	0
Operating income	0	0	0	0
Other non-operating income	0	0	0	0
Interest charges	0	0	0	0
Income before income taxes	0	0	0	0
Income tax expense	0	0	0	0
Net income	0	0	0	0
Intersegment eliminations \| Distribution segment
Operating revenues	808	814	2,314	2,479
Intersegment eliminations \| Pipeline and storage segment
Operating revenues	160,751	139,480	445,952	384,843
Intersegment eliminations \| Purchased gas cost
Purchased gas cost	$ (161,304)	$ (140,053)	$ (447,545)	$ (386,437)

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Income Statement [Abstract]
Net unrealized holding gains (losses) on available-for-sale securities, tax	$ (35)	$ (31)	$ 29	$ (98)
Amortization and unrealized gains (losses) on interest rate agreements, tax	$ 12,580	$ 46,168	$ 10,171	$ 68,136

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Cash Flows From Operating Activities
Net income	$ 767,338	$ 702,755
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization expense	445,063	395,461
Deferred income taxes	75,407	40,899
Other	(38,360)	(15,941)
Net assets / liabilities from risk management activities	(1,545)	(7,167)
Net change in Winter Storm Uri current regulatory asset (See Note 8)	2,021,889	0
Net change in other operating assets and liabilities	(48,284)	(186,691)
Net cash provided by operating activities	3,221,508	929,316
Cash Flows From Investing Activities
Capital expenditures	(2,083,486)	(1,726,039)
Debt and equity securities activities, net	(7,302)	3,594
Other, net	13,469	7,876
Net cash used in investing activities	(2,077,319)	(1,714,569)
Cash Flows From Financing Activities
Net decrease in short-term debt	(184,967)	0
Net proceeds from equity issuances	671,630	675,320
Issuance of common stock through stock purchase and employee retirement plans	11,660	11,670
Proceeds from issuance of long-term debt	797,258	798,802
Proceeds from issuance of securitized long-term debt by AEK	95,000	0
Proceeds from term loan	2,020,000	0
Repayment of term loan	(2,020,000)	0
Repayment of long-term debt	(2,200,000)	(200,000)
Cash dividends paid	(319,074)	(279,256)
Debt issuance costs	(7,864)	(8,196)
Securitized debt issuance costs	(1,273)	0
Other	0	(1,735)
Net cash provided by (used in) financing activities	(1,137,630)	996,605
Net increase in cash and cash equivalents and restricted cash and cash equivalents	6,559	211,352
Cash and cash equivalents and restricted cash and cash equivalents at beginning of period	51,554	116,723
Cash and cash equivalents and restricted cash and cash equivalents at end of period	$ 58,113	$ 328,075

Nature of Business

Nature of Business	9 Months Ended
Nature of Business	Jun. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Business	Nature of Business Atmos Energy Corporation (“Atmos Energy” or the “Company”) and its subsidiaries are engaged in the regulated natural gas distribution and pipeline and storage businesses. Our distribution business is subject to federal and state regulation and/or regulation by local authorities in each of the states in which our regulated divisions and subsidiaries operate. Our distribution business delivers natural gas through sales and transportation arrangements to over 3.3 million residential, commercial, public authority and industrial customers through our six regulated distribution divisions, which at June 30, 2023, covered service areas located in eight states. Our pipeline and storage business, which is also subject to federal and state regulations, includes the transportation of natural gas to our Texas and Louisiana distribution systems and the management of our underground storage facilities used to support our distribution business in various states.

Unaudited Financial Information

Unaudited Financial Information	9 Months Ended
Unaudited Financial Information	Jun. 30, 2023
Accounting Policies [Abstract]
Unaudited Financial Information	Unaudited Financial Information These consolidated interim-period financial statements have been prepared in accordance with accounting principles generally accepted in the United States on the same basis as those used for the Company’s audited consolidated financial statements included in our Annual Report on Form 10-K for the fiscal year ended September 30, 2022. In the opinion of management, all material adjustments (consisting of normal recurring accruals) necessary for a fair presentation have been made to the unaudited consolidated interim-period financial statements. These consolidated interim-period financial statements are condensed as permitted by the instructions to Form 10-Q and should be read in conjunction with the audited consolidated financial statements of Atmos Energy Corporation included in our Annual Report on Form 10-K for the fiscal year ended September 30, 2022. Because of seasonal and other factors, the results of operations for the nine-month period ended June 30, 2023 are not indicative of our results of operations for the full 2023 fiscal year, which ends September 30, 2023. No events have occurred subsequent to the balance sheet date that would require recognition or disclosure in the condensed consolidated financial statements. Significant accounting policies Except as noted below related to our policies regarding restricted cash and cash equivalents and securitized intangible asset, our accounting policies are described in Note 2 to the consolidated financial statements in our Annual Report on Form 10-K for the fiscal year ended September 30, 2022. During the second quarter of fiscal 2023, we completed our annual goodwill impairment assessment using a qualitative assessment, as permitted under U.S. GAAP. We test for goodwill at the reporting unit level on an annual basis and between annual tests if an event occurs or circumstances change that would more likely than not reduce the fair value of the reporting unit. Based on the assessment performed, we determined that our goodwill was not impaired. Restricted cash and cash equivalents Restricted cash and cash equivalents consists of funds that are contractually or legally restricted as to usage or withdrawal and have been presented separately from cash and cash equivalents on our condensed consolidated balance sheets. Restricted cash and cash equivalents accounts were established for payment of Securitized Utility Tariff Bonds issuance costs and payment of debt service on those bonds as well as certain ongoing costs of Atmos Energy Kansas Securitization I, LLC (AEK). Securitized intangible asset Our securitized intangible asset represents the Securitized Utility Tariff Property that AEK acquired from Atmos Energy in the third quarter of fiscal 2023 as part of a securitization transaction. This transaction is discussed in further detail in Notes 8 and 9 to the condensed consolidated financial statements. The securitized intangible asset is stated at cost, net of accumulated amortization, and is amortized over the life of the asset in proportion to the pattern of economic benefit based on expected future undiscounted cash flows. At the end of its life, this securitized intangible asset will have no residual value. We review amortizable intangible assets for impairment whenever events or changes in circumstances indicate that the carrying amount of such assets may not be recoverable. If such a review should indicate that the carrying amount of amortizable intangible assets is not recoverable, we reduce the carrying amount of such assets to fair value. Regulatory assets and liabilities Accounting principles generally accepted in the United States require cost-based, rate-regulated entities that meet certain criteria to reflect the authorized recovery of costs due to regulatory decisions in their financial statements. As a result, certain costs are permitted to be capitalized rather than expensed because they can be recovered through rates. We record certain costs as regulatory assets when future recovery through customer rates is considered probable. Regulatory liabilities are recorded when it is probable that revenues will be reduced for amounts that will be credited to customers through the ratemaking process. Substantially all of our regulatory assets are recorded as a component of other current assets and deferred charges and other assets and our regulatory liabilities are recorded as a component of other current liabilities and deferred credits and other liabilities. Deferred gas costs are recorded either in other current assets or liabilities. Significant regulatory assets and liabilities as of June 30, 2023 and September 30, 2022 included the following: June 30, September 30, (In thousands) Regulatory assets: Pension and postretirement benefit costs $ 22,941 $ 31,122 Infrastructure mechanisms (1) 218,999 235,972 Winter Storm Uri incremental costs (2) 32,441 2,109,454 Deferred gas costs 48,649 119,742 Regulatory excess deferred taxes (3) 47,252 47,311 Recoverable loss on reacquired debt 3,280 3,406 Deferred pipeline record collection costs 52,588 36,898 Other 16,430 21,467 $ 442,580 $ 2,605,372 Regulatory liabilities: Regulatory excess deferred taxes (3) $ 425,440 $ 545,021 Regulatory cost of removal obligation 574,098 568,307 Deferred gas costs 34,933 28,834 Asset retirement obligation 5,737 5,737 APT annual adjustment mechanism 42,797 31,138 Pension and postretirement benefit costs 141,032 156,857 Other 27,055 23,013 $ 1,251,092 $ 1,358,907 (1) Infrastructure mechanisms in Texas, Louisiana and Tennessee allow for the deferral of all eligible expenses associated with capital expenditures incurred pursuant to these rules, including the recording of interest on deferred expenses until the next rate proceeding (rate case or annual rate filing), at which time investment and costs would be recoverable through base rates. (2) Includes extraordinary gas costs incurred during Winter Storm Uri and certain related carrying costs. See Note 8 to the condensed consolidated financial statements for further information. (3) Regulatory excess deferred taxes represent changes in our net deferred tax liability related to our cost of service ratemaking due to the enactment of Tax Cuts and Jobs Act of 2017 (the "TCJA") and a Kansas legislative change enacted in fiscal 2020. See Note 12 to the condensed consolidated financial statements for further information.

Segment Information

Segment Information	9 Months Ended
Segment Information	Jun. 30, 2023
Segment Reporting [Abstract]
Segment Information	Segment Information We manage and review our consolidated operations through the following reportable segments: • The distribution segment is primarily comprised of our regulated natural gas distribution and related sales operations in eight states. • The pipeline and storage segment is comprised primarily of the pipeline and storage operations of our Atmos Pipeline-Texas division and our natural gas transmission operations in Louisiana. The accounting policies of the segments are the same as those described in the summary of significant accounting policies found in our Annual Report on Form 10-K for the fiscal year ended September 30, 2022. Income statements and capital expenditures for the three and nine months ended June 30, 2023 and 2022 by segment are presented in the following tables: Three Months Ended June 30, 2023 Distribution Pipeline and Storage Eliminations Consolidated (In thousands) Operating revenues from external parties $ 615,259 $ 47,474 $ — $ 662,733 Intersegment revenues 808 160,751 (161,559) — Total operating revenues 616,067 208,225 (161,559) 662,733 Purchased gas cost 206,048 (194) (161,304) 44,550 Operation and maintenance expense 138,351 56,953 (255) 195,049 Depreciation and amortization expense 107,809 42,917 — 150,726 Taxes, other than income 92,180 10,975 — 103,155 Operating income 71,679 97,574 — 169,253 Other non-operating income 6,695 9,475 — 16,170 Interest charges 16,146 15,188 — 31,334 Income before income taxes 62,228 91,861 — 154,089 Income tax expense 2,589 13,693 — 16,282 Net income $ 59,639 $ 78,168 $ — $ 137,807 Capital expenditures $ 512,585 $ 155,552 $ — $ 668,137 Three Months Ended June 30, 2022 Distribution Pipeline and Storage Eliminations Consolidated (In thousands) Operating revenues from external parties $ 772,497 $ 43,932 $ — $ 816,429 Intersegment revenues 814 139,480 (140,294) — Total operating revenues 773,311 183,412 (140,294) 816,429 Purchased gas cost 390,559 (1,347) (140,053) 249,159 Operation and maintenance expense 133,654 48,912 (241) 182,325 Depreciation and amortization expense 97,106 37,125 — 134,231 Taxes, other than income 85,933 10,194 — 96,127 Operating income 66,059 88,528 — 154,587 Other non-operating income 6,708 6,555 — 13,263 Interest charges 12,341 13,849 — 26,190 Income before income taxes 60,426 81,234 — 141,660 Income tax expense 3,025 10,088 — 13,113 Net income $ 57,401 $ 71,146 $ — $ 128,547 Capital expenditures $ 417,244 $ 118,766 $ — $ 536,010 Nine Months Ended June 30, 2023 Distribution Pipeline and Storage Eliminations Consolidated (In thousands) Operating revenues from external parties $ 3,554,389 $ 133,326 $ — $ 3,687,715 Intersegment revenues 2,314 445,952 (448,266) — Total operating revenues 3,556,703 579,278 (448,266) 3,687,715 Purchased gas cost 1,896,986 (431) (447,545) 1,449,010 Operation and maintenance expense 426,173 149,329 (721) 574,781 Depreciation and amortization expense 319,783 125,280 — 445,063 Taxes, other than income 275,002 30,782 — 305,784 Operating income 638,759 274,318 — 913,077 Other non-operating income 20,934 33,833 — 54,767 Interest charges 60,405 45,059 — 105,464 Income before income taxes 599,288 263,092 — 862,380 Income tax expense 56,707 38,335 — 95,042 Net income $ 542,581 $ 224,757 $ — $ 767,338 Capital expenditures $ 1,381,118 $ 702,368 $ — $ 2,083,486 Nine Months Ended June 30, 2022 Distribution Pipeline and Storage Eliminations Consolidated (In thousands) Operating revenues from external parties $ 3,353,800 $ 125,234 $ — $ 3,479,034 Intersegment revenues 2,479 384,843 (387,322) — Total operating revenues 3,356,279 510,077 (387,322) 3,479,034 Purchased gas cost 1,881,212 (3,075) (386,437) 1,491,700 Operation and maintenance expense 378,479 127,193 (885) 504,787 Depreciation and amortization expense 286,515 108,946 — 395,461 Taxes, other than income 242,214 29,292 — 271,506 Operating income 567,859 247,721 — 815,580 Other non-operating income 9,173 18,005 — 27,178 Interest charges 36,046 38,923 — 74,969 Income before income taxes 540,986 226,803 — 767,789 Income tax expense 35,163 29,871 — 65,034 Net income $ 505,823 $ 196,932 $ — $ 702,755 Capital expenditures $ 1,217,094 $ 508,945 $ — $ 1,726,039 Balance sheet information at June 30, 2023 and September 30, 2022 by segment is presented in the following tables: June 30, 2023 Distribution Pipeline and Storage Eliminations Consolidated (In thousands) Net property, plant and equipment $ 13,938,357 $ 5,079,984 $ — $ 19,018,341 Total assets $ 21,015,851 $ 5,369,445 $ (4,613,767) $ 21,771,529 September 30, 2022 Distribution Pipeline and Storage Eliminations Consolidated (In thousands) Net property, plant and equipment $ 12,723,532 $ 4,516,707 $ — $ 17,240,239 Total assets $ 21,424,586 $ 4,797,206 $ (4,028,803) $ 22,192,989

Earnings Per Share

Earnings Per Share	9 Months Ended
Earnings Per Share	Jun. 30, 2023
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share We use the two-class method of computing earnings per share because we have participating securities in the form of non-vested restricted stock units with a nonforfeitable right to dividend equivalents, for which vesting is predicated solely on the passage of time. The calculation of earnings per share using the two-class method excludes income attributable to these participating securities from the numerator and excludes the dilutive impact of those shares from the denominator. Basic weighted average shares outstanding is calculated based upon the weighted average number of common shares outstanding during the periods presented. Also, this calculation includes fully vested stock awards that have not yet been issued as common stock. Additionally, the weighted average shares outstanding for diluted EPS includes the incremental effects of the forward sale agreements, discussed in Note 7 to the condensed consolidated financial statements, when the impact is dilutive. Basic and diluted earnings per share for the three and nine months ended June 30, 2023 and 2022 are calculated as follows: Three Months Ended June 30 Nine Months Ended June 30 2023 2022 2023 2022 (In thousands, except per share amounts) Basic Earnings Per Share Net income $ 137,807 $ 128,547 $ 767,338 $ 702,755 Less: Income allocated to participating securities 83 79 482 465 Income available to common shareholders $ 137,724 $ 128,468 $ 766,856 $ 702,290 Basic weighted average shares outstanding 146,051 139,881 143,938 136,799 Net income per share — Basic $ 0.94 $ 0.92 $ 5.33 $ 5.13 Diluted Earnings Per Share Income available to common shareholders $ 137,724 $ 128,468 $ 766,856 $ 702,290 Effect of dilutive shares — — — — Income available to common shareholders $ 137,724 $ 128,468 $ 766,856 $ 702,290 Basic weighted average shares outstanding 146,051 139,881 143,938 136,799 Dilutive shares 16 346 60 256 Diluted weighted average shares outstanding 146,067 140,227 143,998 137,055 Net income per share — Diluted $ 0.94 $ 0.92 $ 5.33 $ 5.12

Revenue and Accounts Receivable

Revenue and Accounts Receivable	9 Months Ended
Revenue and Accounts Receivable	Jun. 30, 2023
Revenue from Contract with Customer [Abstract]
Revenue and Accounts Receivable	Revenue and Accounts Receivable Revenue Our revenue recognition policy is fully described in Note 2 to the consolidated financial statements in our Annual Report on Form 10-K for the fiscal year ended September 30, 2022. The following tables disaggregate our revenue from contracts with customers by customer type and segment and provide a reconciliation to total operating revenues, including intersegment revenues, for the three and nine months ended June 30, 2023 and 2022. Three Months Ended June 30, 2023 Three Months Ended June 30, 2022 Distribution Pipeline and Storage Distribution Pipeline and Storage (In thousands) Gas sales revenues: Residential $ 380,099 $ — $ 441,806 $ — Commercial 165,930 — 231,309 — Industrial 23,533 — 57,045 — Public authority and other 8,562 — 13,080 — Total gas sales revenues 578,124 — 743,240 — Transportation revenues 27,988 212,322 27,216 186,405 Miscellaneous revenues 2,706 4,397 2,453 3,104 Revenues from contracts with customers 608,818 216,719 772,909 189,509 Alternative revenue program revenues (1) 6,772 (8,494) (77) (6,097) Other revenues 477 — 479 — Total operating revenues $ 616,067 $ 208,225 $ 773,311 $ 183,412 Nine Months Ended June 30, 2023 Nine Months Ended June 30, 2022 Distribution Pipeline and Storage Distribution Pipeline and Storage (In thousands) Gas sales revenues: Residential $ 2,276,240 $ — $ 2,108,349 $ — Commercial 953,409 — 910,400 — Industrial 127,792 — 160,098 — Public authority and other 54,074 — 54,668 — Total gas sales revenues 3,411,515 — 3,233,515 — Transportation revenues 93,661 597,822 87,886 514,114 Miscellaneous revenues 7,650 8,271 7,732 11,931 Revenues from contracts with customers 3,512,826 606,093 3,329,133 526,045 Alternative revenue program revenues (1) 42,360 (26,815) 25,663 (15,968) Other revenues 1,517 — 1,483 — Total operating revenues $ 3,556,703 $ 579,278 $ 3,356,279 $ 510,077 (1) In our distribution segment, we have weather-normalization adjustment mechanisms that serve to mitigate the effects of weather on our revenue. Additionally, APT has a regulatory mechanism that requires that APT shares with its tariffed customers 75% of the difference between the total non-tariffed revenues earned during a test period and a revenue benchmark. Accounts receivable and allowance for uncollectible accounts Accounts receivable arise from natural gas sales to residential, commercial, industrial, public authority and other customers. Our accounts receivable balance includes unbilled amounts which represent a customer’s consumption of gas from the date of the last cycle billing through the last day of the month. Our policy related to the accounting for our accounts receivable and allowance for uncollectible accounts is fully described in Note 2 to the consolidated financial statements in our Annual Report on Form 10-K for the fiscal year ended September 30, 2022. During the nine months ended June 30, 2023, there were no material changes to this policy. Rollforwards of our allowance for uncollectible accounts for the three and nine months ended June 30, 2023 and 2022 are presented in the table below. The allowance excludes the gas cost portion of customers’ bills for approximately 81 percent of our customers as we have the ability to collect these gas costs through our gas cost recovery mechanisms in most of our jurisdictions. Three Months Ended June 30, 2023 (In thousands) Beginning balance, March 31, 2023 $ 52,751 Current period provisions 1,758 Write-offs charged against allowance (5,902) Recoveries of amounts previously written off 294 Ending balance, June 30, 2023 $ 48,901 Three Months Ended June 30, 2022 (In thousands) Beginning balance, March 31, 2022 $ 62,213 Current period provisions 5,657 Write-offs charged against allowance (7,430) Recoveries of amounts previously written off 328 Ending balance, June 30, 2022 $ 60,768 Nine Months Ended June 30, 2023 (In thousands) Beginning balance, September 30, 2022 $ 49,993 Current period provisions 22,000 Write-offs charged against allowance (24,656) Recoveries of amounts previously written off 1,564 Ending balance, June 30, 2023 $ 48,901 Nine Months Ended June 30, 2022 (In thousands) Beginning balance, September 30, 2021 $ 64,471 Current period provisions 17,733 Write-offs charged against allowance (22,888) Recoveries of amounts previously written off 1,452 Ending balance, June 30, 2022 $ 60,768

Debt

Debt	9 Months Ended
Debt	Jun. 30, 2023
Debt Disclosure [Abstract]
Debt	DebtThe nature and terms of our debt instruments and credit facilities are described in detail in Note 7 to the consolidated financial statements in our Annual Report on Form 10-K for the fiscal year ended September 30, 2022. Other than as described below, there were no material changes in the terms of our debt instruments during the nine months ended June 30, 2023. Long-term debt at June 30, 2023 and September 30, 2022 consisted of the following: June 30, 2023 September 30, 2022 (In thousands) Unsecured 0.625% Senior Notes, due March 2023 $ — $ 1,100,000 Unsecured 3.00% Senior Notes, due June 2027 500,000 500,000 Unsecured 2.625% Senior Notes, due September 2029 500,000 500,000 Unsecured 1.50% Senior Notes, due January 2031 600,000 600,000 Unsecured 5.45% Senior Notes, due October 2032 300,000 — Unsecured 5.95% Senior Notes, due October 2034 200,000 200,000 Unsecured 5.50% Senior Notes, due June 2041 400,000 400,000 Unsecured 4.15% Senior Notes, due January 2043 500,000 500,000 Unsecured 4.125% Senior Notes, due October 2044 750,000 750,000 Unsecured 4.30% Senior Notes, due October 2048 600,000 600,000 Unsecured 4.125% Senior Notes, due March 2049 450,000 450,000 Unsecured 3.375% Senior Notes, due September 2049 500,000 500,000 Unsecured 2.85% Senior Notes, due February 2052 600,000 600,000 Unsecured 5.75% Senior Notes, due October 2052 500,000 — Floating-rate Senior Notes, due March 2023 — 1,100,000 Medium-term note Series A, 1995-1, 6.67%, due December 2025 10,000 10,000 Unsecured 6.75% Debentures, due July 2028 150,000 150,000 Finance lease obligations 50,766 51,850 Total long-term debt 6,610,766 8,011,850 Less: Original issue discount on unsecured senior notes and debentures 6,188 3,704 Debt issuance cost 49,420 46,042 Current maturities of long-term debt 1,540 2,201,457 Total long-term debt, net $ 6,553,618 $ 5,760,647 On October 3, 2022, we completed a public offering of $500 million of 5.75% senior notes due October 2052, with an effective interest rate of 4.50%, after giving effect to the offering costs and settlement of our interest rate swaps, and $300 million of 5.45% senior notes due October 2032, with an effective interest rate of 5.57%, after giving effect to the offering costs. The net proceeds from the offering, after the underwriting discount and offering expenses, of $789.4 million were used for general corporate purposes. Short-term debt We utilize short-term debt to provide cost-effective, short-term financing until it can be replaced with a balance of long-term debt and equity financing that achieves the Company’s desired capital structure. Our short-term borrowing requirements are driven primarily by construction work in progress and the seasonal nature of the natural gas business. Our short-term borrowing requirements are satisfied through a combination of a $1.5 billion commercial paper program and four committed revolving credit facilities with third-party lenders that provide $2.5 billion of total working capital funding. Our commercial paper program is supported by a five-year unsecured $1.5 billion credit facility that expires on March 31, 2027. This facility bears interest at a base rate or at a SOFR-based rate for the applicable interest period, plus a margin ranging from zero percent to 0.25 percent for base rate advances or a margin ranging from 0.75 percent to 1.25 percent for SOFR-based advances, based on the Company’s credit ratings. Additionally, the facility contains a $250 million accordion feature, which provides the opportunity to increase the total committed loan to $1.75 billion. At June 30, 2023, there were no amounts outstanding under our commercial paper program. At September 30, 2022, there was $185.0 million outstanding under our commercial paper program. We also have a $900 million three-year unsecured revolving credit facility, which expires March 31, 2025 and is used to provide additional working capital funding. This facility bears interest at a base rate or at a SOFR-based rate for the applicable interest period, plus a margin ranging from zero percent to 0.25 percent for base rate advances or a margin ranging from 0.75 percent to 1.25 percent for SOFR-based advances, based on the Company's credit ratings. Additionally, the facility contains a $100 million accordion feature, which provides the opportunity to increase the total committed loan to $1.0 billion. At June 30, 2023 and September 30, 2022, there were no borrowings outstanding under this facility. Additionally, we have a $50 million 364-day unsecured facility, which was renewed April 1, 2023 and is used to provide working capital funding. There were no borrowings outstanding under this facility as of June 30, 2023 and September 30, 2022. Finally, we have a $50 million 364-day unsecured revolving credit facility, which was renewed March 31, 2023 and is used to issue letters of credit and to provide working capital funding. At June 30, 2023, there were no borrowings outstanding under this facility; however, outstanding letters of credit reduced the total amount available to us to $44.4 million. On March 3, 2023, we entered into a term loan agreement for a $2.02 billion senior unsecured term loan facility that would have matured December 31, 2023. The proceeds from the facility, along with cash on hand, were used to repay at maturity on March 9, 2023 our outstanding $1.1 billion senior notes and $1.1 billion floating-rate senior notes. Under the terms of the facility, we were required to prepay the facility prior to maturity upon receiving proceeds from the issuance of certain securities that were part of a utility recovery securitization transaction authorized by the state of Texas. On March 23, 2023, we received those proceeds (see Note 8), and on March 24, 2023 we prepaid the term loan facility, thus terminating the term loan agreement and all obligations thereunder. Debt covenants The availability of funds under these credit facilities is subject to conditions specified in the respective credit agreements, all of which we currently satisfy. These conditions include our compliance with financial covenants and the continued accuracy of representations and warranties contained in these agreements. We are required by the financial covenants in each of these facilities to maintain, at the end of each fiscal quarter, a ratio of total-debt-to-total-capitalization of no greater than 70 percent. At June 30, 2023, our total-debt-to-total-capitalization ratio, as defined in the agreements, was 39 percent. In addition, both the interest margin and the fee that we pay on unused amounts under certain of these facilities are subject to adjustment depending upon our credit ratings. These credit facilities and our public indentures contain usual and customary covenants for our business, including covenants substantially limiting liens, substantial asset sales and mergers. Additionally, our public debt indentures relating to our senior notes and debentures, as well as certain of our revolving credit agreements, each contain a default provision that is triggered if outstanding indebtedness arising out of any other credit agreements in amounts ranging from in excess of $15 million to in excess of $100 million becomes due by acceleration or if not paid at maturity. We were in compliance with all of our debt covenants as of June 30, 2023. If we were unable to comply with our debt covenants, we would likely be required to repay our outstanding balances on demand, provide additional collateral or take other corrective actions.

Shareholders' Equity

Shareholders' Equity	9 Months Ended
Shareholders' Equity	Jun. 30, 2023
Equity [Abstract]
Shareholders' Equity	Shareholders' Equity The following tables present a reconciliation of changes in stockholders' equity for the three and nine months ended June 30, 2023 and 2022. Common stock Additional Accumulated Retained Total Number of Stated (In thousands, except share and per share data) Balance, September 30, 2022 140,896,598 $ 704 $ 5,838,118 $ 369,112 $ 3,211,157 $ 9,419,091 Net income — — — — 271,860 271,860 Other comprehensive income — — — 22,218 — 22,218 Cash dividends ($0.74 per share) — — — — (104,552) (104,552) Common stock issued: Public and other stock offerings 2,147,210 11 223,768 — — 223,779 Stock-based compensation plans 111,953 1 3,877 — — 3,878 Balance, December 31, 2022 143,155,761 716 6,065,763 391,330 3,378,465 9,836,274 Net income — — — — 357,671 357,671 Other comprehensive loss — — — (30,333) — (30,333) Cash dividends ($0.74 per share) — — — — (106,173) (106,173) Common stock issued: Public and other stock offerings 1,316,930 6 143,808 — — 143,814 Stock-based compensation plans 11,959 — 3,952 — — 3,952 Balance, March 31, 2023 144,484,650 722 6,213,523 360,997 3,629,963 10,205,205 Net income — — — — 137,807 137,807 Other comprehensive income — — — 43,406 — 43,406 Cash dividends ($0.74 per share) — — — — (108,349) (108,349) Common stock issued: Public and other stock offerings 2,754,533 15 315,682 — — 315,697 Stock-based compensation plans 65,355 — 8,615 — — 8,615 Balance, June 30, 2023 147,304,538 $ 737 $ 6,537,820 $ 404,403 $ 3,659,421 $ 10,602,381 Common stock Additional Accumulated Retained Total Number of Stated (In thousands, except share and per share data) Balance, September 30, 2021 132,419,754 $ 662 $ 5,023,751 $ 69,803 $ 2,812,673 $ 7,906,889 Net income — — — — 249,209 249,209 Other comprehensive loss — — — (45,947) — (45,947) Cash dividends ($0.68 per share) — — — — (90,411) (90,411) Common stock issued: Public and other stock offerings 2,730,115 13 265,848 — — 265,861 Stock-based compensation plans 275,212 2 3,942 — — 3,944 Balance, December 31, 2021 135,425,081 677 5,293,541 23,856 2,971,471 8,289,545 Net income — — — — 324,999 324,999 Other comprehensive income — — — 121,723 — 121,723 Cash dividends ($0.68 per share) — — — — (93,533) (93,533) Common stock issued: Public and other stock offerings 3,509,116 18 336,451 — — 336,469 Stock-based compensation plans 77,832 — 4,028 — — 4,028 Balance, March 31, 2022 139,012,029 695 5,634,020 145,579 3,202,937 8,983,231 Net income — — — — 128,547 128,547 Other comprehensive income — — — 159,631 — 159,631 Cash dividends ($0.68 per share) — — — — (95,312) (95,312) Common stock issued: Public and other stock offerings 801,952 4 84,656 — — 84,660 Stock-based compensation plans 74,775 — 7,414 — — 7,414 Balance, June 30, 2022 139,888,756 $ 699 $ 5,726,090 $ 305,210 $ 3,236,172 $ 9,268,171 Shelf Registration, At-the-Market Equity Sales Program and Equity Issuances On March 31, 2023, we filed a shelf registration statement with the Securities and Exchange Commission (SEC) that allows us to issue up to $5.0 billion in common stock and/or debt securities, which expires March 31, 2026. This shelf registration statement replaced our previous shelf registration statement which was filed on June 29, 2021. At June 30, 2023, $4.0 billion of securities were available for issuance under this shelf registration statement. On March 31, 2023, we filed a prospectus supplement under the shelf registration statement relating to an at-the-market (ATM) equity sales program under which we may issue and sell shares of our common stock up to an aggregate offering price of $1.0 billion through March 31, 2026 (including shares of common stock that may be sold pursuant to forward sale agreements entered into concurrently with the ATM equity sales program). This ATM equity sales program replaced our previous ATM equity sales program, filed on March 23, 2022. During the nine months ended June 30, 2023, we executed forward sales under our ATM equity sales program with various forward sellers who borrowed and sold 4,116,489 shares of our common stock at an aggregate price of $485.7 million. During the nine months ended June 30, 2023, we also settled forward sale agreements with respect to 6,116,848 shares that had been borrowed and sold by various forward sellers under the ATM program for net proceeds of $671.6 million. As of June 30, 2023, $771.3 million of equity was available for issuance under our existing ATM program. Additionally, we had $589.5 million in available proceeds from outstanding forward sale agreements, as detailed below. Maturity Shares Available Net Proceeds Available Forward Price March 28, 2024 2,099,709 $ 247,295 $ 117.78 June 28, 2024 927,939 108,946 $ 117.41 September 30, 2024 1,133,978 132,104 $ 116.50 December 31, 2024 864,175 101,138 $ 117.03 Total 5,025,801 $ 589,483 $ 117.29 Accumulated Other Comprehensive Income (Loss) We record deferred gains (losses) in AOCI related to available-for-sale debt securities and interest rate agreement cash flow hedges. Deferred gains (losses) for our available-for-sale debt securities are recognized in earnings upon settlement, while deferred gains (losses) related to our interest rate agreement cash flow hedges are recognized in earnings on a straight-line basis over the life of the related financing. The following tables provide the components of our accumulated other comprehensive income (loss) balances, net of the related tax effects allocated to each component of other comprehensive income (loss). Available- Interest Rate Total (In thousands) September 30, 2022 $ (495) $ 369,607 $ 369,112 Other comprehensive income before reclassifications 100 36,781 36,881 Amounts reclassified from accumulated other comprehensive income — (1,590) (1,590) Net current-period other comprehensive income 100 35,191 35,291 June 30, 2023 $ (395) $ 404,798 $ 404,403 Available- Interest Rate Total (In thousands) September 30, 2021 $ 47 $ 69,756 $ 69,803 Other comprehensive income (loss) before reclassifications (336) 233,511 233,175 Amounts reclassified from accumulated other comprehensive income — 2,232 2,232 Net current-period other comprehensive income (loss) (336) 235,743 235,407 June 30, 2022 $ (289) $ 305,499 $ 305,210

Winter Storm Uri

Winter Storm Uri	9 Months Ended
Winter Storm Uri	Jun. 30, 2023
Unusual or Infrequent Items, or Both [Abstract]
Winter Storm Uri	Winter Storm Uri Overview As described in Note 9 to the consolidated financial statements in our Annual Report on Form 10-K for the fiscal year ended September 30, 2022, a historic winter storm impacted supply, market pricing and demand for natural gas in our service territories in mid-February 2021. During this time, the governors of Kansas and Texas each declared a state of emergency, and certain regulatory agencies issued emergency orders that impacted the utility and natural gas industries, including statewide utilities curtailment programs and orders encouraging or requiring jurisdictional natural gas utilities to work to ensure customers were provided with safe and reliable natural gas service. Due to the historic nature of this winter storm, we experienced unforeseeable and unprecedented market pricing for gas costs, which resulted in aggregated natural gas purchases during the month of February of approximately $2.3 billion. These gas costs were paid using funds received from a public offering of debt securities completed in March 2021 of $2.2 billion. On March 3, 2023, we entered into a term loan agreement for a $2.02 billion senior unsecured term loan facility and used the proceeds, along with cash on hand, to repay at maturity the outstanding $2.2 billion senior notes that matured on March 9, 2023. Regulatory Asset Accounting Our purchased gas costs are recoverable through purchased gas cost adjustment mechanisms in each state where we operate. Due to the unprecedented level of purchased gas costs incurred during Winter Storm Uri, the Kansas Corporation Commission (KCC) and the Railroad Commission of Texas (RRC) issued orders authorizing natural gas utilities to record a regulatory asset to account for the extraordinary costs associated with the winter storm. Pursuant to these orders, we recorded a regulatory asset for incremental costs, including certain carrying costs, incurred in Kansas and Texas. As of June 30, 2023, the regulatory assets related to costs incurred in Kansas and in Texas have been relieved as discussed below. Additionally, pursuant to a separate regulatory order issued by the RRC, we have deferred $32.4 million in carrying costs incurred after September 1, 2022, which we anticipate recovering in future regulatory filings. We have recorded the regulatory asset for Texas as a long-term asset in deferred charges and other assets as of June 30, 2023. Securitization Proceedings To minimize the impact on the customer bill by extending the recovery periods for these unprecedented purchased gas costs, the Kansas and Texas State Legislatures each enacted securitization legislation during fiscal 2021, as described in further detail in Note 9 to the consolidated financial statements in our Annual Report on Form 10-K for the fiscal year ended September 30, 2022. Kansas The KCC issued a financing order on October 25, 2022, which authorized us to securitize, through the issuance of bonds, the qualified extraordinary costs associated with the winter storm. As part of the order, we created AEK, a special-purpose, wholly-owned subsidiary of Atmos Energy, and filed a registration statement with the SEC for the purpose of issuing securitized utility tariff bonds. The registration statement was declared effective on June 8, 2023. As discussed in Note 9 to the condensed consolidated financial statements, AEK issued $95 million of Securitized Utility Tariff Bonds and used the proceeds from the issuance to purchase the Securitized Utility Tariff Property from Atmos Energy for $92.3 million. As a result of this transaction, Atmos Energy relieved $92.3 million of a regulatory asset related to costs incurred in Kansas that was recorded in deferred charges and other assets. Texas On February 8, 2022, the RRC issued a Financing Order that authorized the Texas Public Financing Authority (TPFA) to issue customer rate relief bonds to securitize the costs that were approved in the Final Determination over a period not to exceed 30 years. The TPFA authorized the creation of the Texas Natural Gas Securitization Finance Corporation (the Finance Corporation) as an issuing financing entity for the purpose of issuing customer rate relief bonds. On March 23, 2023, the Finance Corporation issued $3.5 billion in customer rate relief bonds with varying scheduled final maturities from 12 to 18 years. The bonds are obligations of the Finance Corporation, payable from the customer rate relief charges and other bond collateral, and are not an obligation of Atmos Energy. When we begin collecting the customer rate relief charges on October 1, 2023, such property shall be solely owned by the Finance Corporation and not available to pay creditors of Atmos Energy. On March 23, 2023, we received proceeds from the Finance Corporation in the amount of $2.02 billion, and we relieved $2.02 billion in regulatory assets related to costs incurred in Texas. U.S. GAAP does not provide comprehensive recognition and measurement guidance for many forms of government assistance received by business entities. Accordingly, we have accounted for the proceeds received from the Finance Corporation by analogy to International Accounting Standards No. 20, "Accounting for Government Grants and Disclosure of Government Assistance" consistent with a grant related to income. The proceeds received and the corresponding derecognition of the deferred regulatory asset have been reflected in purchased gas cost and interest charges in our condensed consolidated statements of comprehensive income. As the proceeds reflect the recovery of the regulatory asset, there was no impact to earnings. The proceeds are reflected in our condensed consolidated statements of cash flow as an increase in operating cash flow. As discussed in Note 6 to the condensed consolidated financial statements, we used the proceeds from the Finance Corporation to repay a term loan facility.

Variable Interest Entity

Variable Interest Entity	9 Months Ended
Variable Interest Entity	Jun. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Variable Interest Entity	Variable Interest EntityAEK is a special-purpose, wholly-owned subsidiary of Atmos Energy that was formed for the purpose of issuing securitized bonds to recover extraordinary costs incurred during Winter Storm Uri. On June 20, 2023, AEK completed a public offering of $95 million of 5.155% Series 2023-A Senior Secured Securitized Utility Tariff Bonds with a term of 10 years and semi-annual payments of principal and interest. The net proceeds from the offering, after the underwriting discount and offering expenses, of $93.7 million were primarily used to purchase the Securitized Utility Tariff Property from Atmos Energy for $92.3 million. The bonds are governed by an indenture between AEK and the indenture trustee. The indenture contains certain covenants that restrict AEK's ability to sell, transfer, convey, exchange or otherwise dispose of its assets. AEK's assets cannot be used to settle Atmos Energy's obligations, and the holders of the Securitized Utility Tariff Bonds have no recourse against Atmos Energy. See Note 8 to the condensed consolidated financial statements for additional information about the securitization transaction. Because AEK's equity at risk is less than 1% of its total assets, it is considered to be a variable interest entity. Atmos Energy has the power to direct the most significant financial and operating activities of AEK, including billing, collections and remittance of customer cash receipts to enable AEK to service the principal and interest payments due under the Securitized Utility Tariff Bonds. Atmos Energy also has the obligation to absorb losses and rights to receive returns from AEK. Therefore, Atmos Energy is the primary beneficiary of AEK, and as a result, AEK is included in the condensed consolidated financial statements of Atmos Energy. No gain or loss was recognized upon initial consolidation. The Securitized Utility Tariff Property that was acquired by AEK is classified as a securitized intangible asset on our condensed consolidated balance sheets. This securitized intangible asset will be amortized over 10 years, the estimated period needed to collect the required amounts from Atmos Energy's customers to service the Securitized Utility Tariff Bonds, with a weighted average amortization period of 5.31 years. The amortization expense related to the securitized intangible asset will be included in depreciation and amortization expense in our condensed consolidated statements of comprehensive income. We did not record amortization expense related to the securitized intangible asset for the three and nine months ended June 30, 2023 as billing did not begin until July 1, 2023. The following table summarizes the impact of AEK on our condensed consolidated balance sheet, for the period indicated: June 30, 2023 (In thousands) Restricted cash and cash equivalents $ 1,876 Securitized intangible asset, net $ 93,600 Current maturities of securitized long-term debt $ 5,973 Securitized long-term debt $ 89,027 There were no material impacts to the condensed consolidated statements of comprehensive income for the three and nine months ended June 30, 2023. The following table summarizes the maturities of the securitized long-term debt and the amortization expense related to the securitized intangible asset expected to be recognized in our consolidated statements of comprehensive income: Maturities of Securitized Long-Term Debt Amortization Expense of Securitized Intangible Asset For the fiscal year ending: (In thousands) 2023 $ — $ 2,368 2024 9,922 8,073 2025 8,207 8,121 2026 8,635 8,545 2027 9,086 8,991 Thereafter 59,150 57,502 Total $ 95,000 $ 93,600 The securitized long-term debt is recorded at carrying value. The fair value of the securitized long-term debt is determined using third party market value quotations, which are considered Level 2 fair value measurements for debt instruments where fair value is determined using the most recent available quoted market price. The carrying value and fair value of the securitized long-term debt as of June 30, 2023 is $95.0 million and $94.2 million.

Interim Pension and Other Postr

Interim Pension and Other Postretirement Benefit Plan Information	9 Months Ended
	Jun. 30, 2023
Retirement Benefits, Description [Abstract]
Interim Pension and Other Postretirement Benefit Plan Information	Interim Pension and Other Postretirement Benefit Plan Information The components of our net periodic pension cost for our pension and other postretirement benefit plans for the three and nine months ended June 30, 2023 and 2022 are presented in the following tables. Most of these costs are recoverable through our tariff rates. A portion of these costs is capitalized into our rate base or deferred as a regulatory asset or liability. The remaining costs are recorded as a component of operation and maintenance expense or other non-operating expense. In the third quarter of fiscal 2023, due to the retirement of certain executives, we recognized a settlement charge of $1.0 million associated with our Supplemental Executive Retirement Plan and revalued the net periodic pension cost for the remainder of fiscal 2023. The revaluation of the net periodic pension cost for our Supplemental Executive Retirement Plan resulted in a decrease in the discount rate, effective April 30, 2023, to 5.21% from 5.71%, which will decrease our net periodic pension cost by approximately $0.1 million for the remainder of the fiscal year. Three Months Ended June 30 Pension Benefits Other Benefits 2023 2022 2023 2022 (In thousands) Components of net periodic pension cost: Service cost $ 2,915 $ 4,323 $ 1,546 $ 2,559 Interest cost (1) 7,265 5,063 3,478 2,683 Expected return on assets (1) (7,278) (7,383) (2,804) (3,312) Amortization of prior service cost (credit) (1) (30) (58) (3,285) (3,308) Amortization of actuarial (gain) loss (1) 178 1,951 (1,863) — Settlements (1) 1,030 — — — Net periodic pension cost $ 4,080 $ 3,896 $ (2,928) $ (1,378) Nine Months Ended June 30 Pension Benefits Other Benefits 2023 2022 2023 2022 (In thousands) Components of net periodic pension cost: Service cost $ 8,731 $ 12,970 $ 4,637 $ 7,676 Interest cost (1) 21,915 15,190 10,433 8,050 Expected return on assets (1) (21,835) (22,149) (8,411) (9,937) Amortization of prior service cost (credit) (1) (91) (174) (9,856) (9,925) Amortization of actuarial (gain) loss (1) 506 5,853 (5,589) — Settlements (1) 1,030 — — — Net periodic pension cost $ 10,256 $ 11,690 $ (8,786) $ (4,136) (1) The components of net periodic cost other than the service cost component are included in the line item other non-operating expense in the condensed consolidated statements of comprehensive income or are capitalized on the condensed consolidated balance sheets as a regulatory asset or liability, as described in Note 2 to the consolidated financial statements in our Annual Report on Form 10-K for the fiscal year ended September 30, 2022. We made a voluntary contribution of $8.0 million to our pension plan during the third quarter of fiscal 2023. For the nine months ended June 30, 2023 we contributed $9.9 million to our postretirement medical plan. We anticipate contributing a total of between $12 million and $15 million to our postretirement medical plan during fiscal 2023.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
Commitments and Contingencies	Jun. 30, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Litigation and Environmental Matters In the normal course of business, we are subject to various legal and regulatory proceedings. For such matters, we record liabilities when they are considered probable and estimable, based on currently available facts, our historical experience and our estimates of the ultimate outcome or resolution of the liability in the future. While the outcome of these proceedings is uncertain and a loss in excess of the amount we have accrued is possible though not reasonably estimable, it is the opinion of management that any amounts exceeding the accruals will not have a material adverse impact on our financial position, results of operations or cash flows. We are a party to various other litigation and environmental-related matters or claims that have arisen in the ordinary course of our business. While the results of such litigation and response actions to such environmental-related matters or claims cannot be predicted with certainty, we continue to believe the final outcome of such litigation and matters or claims will not have a material adverse effect on our financial condition, results of operations or cash flows. Purchase Commitments Our distribution divisions maintain supply contracts with several vendors that generally cover a period of up to one year. Commitments for estimated base gas volumes are established under these contracts on a monthly basis at contractually negotiated prices. Commitments for incremental daily purchases are made as necessary during the month in accordance with the terms of the individual contract. Our Mid-Tex Division also maintains a limited number of long-term supply contracts to ensure a reliable source of gas for our customers in its service area, which obligate it to purchase specified volumes at prices under contracts indexed to natural gas hubs or fixed price contracts. These purchase commitment contracts are detailed in our Annual Report on Form 10-K for the fiscal year ended September 30, 2022. At June 30, 2023, we were committed to purchase 70.9 Bcf within one year and 91.7 Bcf within two Rate Regulatory Proceedings As of June 30, 2023, routine rate regulatory proceedings were in progress in several of our service areas, which are discussed in further detail below in Management’s Discussion and Analysis — Recent Ratemaking Developments . Except for these proceedings, there were no material changes to rate regulatory proceedings for the nine months ended June 30, 2023.

Income Taxes

Income Taxes	9 Months Ended
Income Taxes	Jun. 30, 2023
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Income Tax Expense Our interim effective tax rates reflect the estimated annual effective tax rates for the fiscal years ended September 30, 2023 and 2022, adjusted for tax expense associated with certain discrete items. The effective tax rates for the three months ended June 30, 2023 and 2022 were 10.6% and 9.3% and for the nine months ended June 30, 2023 and 2022 were 11.0% and 8.5%. These effective tax rates differ from the federal statutory tax rate of 21% primarily due to the amortization of excess deferred federal income tax liabilities, tax credits, state income taxes and other permanent book-to-tax differences. These adjustments have a relative impact on the effective tax rate proportionally to pretax income or loss. Regulatory Excess Deferred Taxes Regulatory excess net deferred taxes represent changes in our net deferred tax liability related to our cost of service ratemaking due to the enactment of the Tax Cuts and Jobs Act of 2017 (the TCJA) and a Kansas legislative change enacted in fiscal 2020. Currently, the regulatory excess net deferred tax liability of $378.2 million is being returned over various periods. Of this amount, $320.7 million is being returned to customers over 35 - 60 months. An additional $54.5 million is being returned to customers on a provisional basis over 15 - 69 years until our regulators establish the final refund periods. The refund of the remaining $3.0 million will be addressed in future rate proceedings. As of June 30, 2023 and September 30, 2022, $147.9 million and $159.8 million is recorded in other current liabilities.

Financial Instruments

Financial Instruments	9 Months Ended
Financial Instruments	Jun. 30, 2023
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Financial Instruments	Financial Instruments We currently use financial instruments to mitigate commodity price risk and interest rate risk. The objectives and strategies for using financial instruments and the related accounting for these financial instruments are fully described in Notes 2 and 15 to the consolidated financial statements in our Annual Report on Form 10-K for the fiscal year ended September 30, 2022. During the nine months ended June 30, 2023, there were no material changes in our objectives, strategies and accounting for using financial instruments. Our financial instruments do not contain any credit-risk-related or other contingent features that could cause payments to be accelerated when our financial instruments are in net liability positions. The following summarizes those objectives and strategies. Commodity Risk Management Activities Our purchased gas cost adjustment mechanisms essentially insulate our distribution segment from commodity price risk; however, our customers are exposed to the effects of volatile natural gas prices. We manage this exposure through a combination of physical storage, fixed-price forward contracts and financial instruments, primarily over-the-counter swap and option contracts, in an effort to minimize the impact of natural gas price volatility on our customers during the winter heating season. We typically seek to hedge between 25 and 50 percent of anticipated heating season gas purchases using financial instruments. For the 2022-2023 heating season (generally October through March), in the jurisdictions where we are permitted to utilize financial instruments, we hedged approximately 32 percent, or 17.7 Bcf, of the winter flowing gas requirements. We have not designated these financial instruments as hedges for accounting purposes. Interest Rate Risk Management Activities We manage interest rate risk by periodically entering into financial instruments to effectively fix the Treasury yield component of the interest cost associated with anticipated financings. In March and April 2023, we entered into forward starting interest rate swaps to effectively fix the Treasury yield component associated with $250 million of planned issuances of unsecured senior notes in fiscal 2024. These swaps were designated as cash flow hedges at the time the agreements were executed. The following table summarizes our existing forward starting interest rate swaps as of June 30, 2023. Planned Debt Issuance Date Amount Hedged (In thousands) Fiscal 2024 $ 700,000 Fiscal 2025 600,000 Fiscal 2026 300,000 $ 1,600,000 Quantitative Disclosures Related to Financial Instruments The following tables present detailed information concerning the impact of financial instruments on our condensed consolidated balance sheet and statements of comprehensive income. As of June 30, 2023, our financial instruments were comprised of both long and short commodity positions. A long position is a contract to purchase the commodity, while a short position is a contract to sell the commodity. As of June 30, 2023, we had 19,735 MMcf of net long commodity contracts outstanding. These contracts have not been designated as hedges. Financial Instruments on the Balance Sheet The following tables present the fair value and balance sheet classification of our financial instruments as of June 30, 2023 and September 30, 2022. The gross amounts of recognized assets and liabilities are netted within our condensed consolidated balance sheets to the extent that we have netting arrangements with our counterparties. However, as of June 30, 2023 and September 30, 2022, no gross amounts and no cash collateral were netted within our consolidated balance sheet. June 30, 2023 Balance Sheet Location Assets Liabilities (In thousands) Designated As Hedges: Interest rate contracts Other current assets / $ 123,716 $ — Interest rate contracts Deferred charges and other assets / 278,771 — Total 402,487 — Not Designated As Hedges: Commodity contracts Other current assets / 2,811 (9,752) Commodity contracts Deferred charges and other assets / 678 (503) Total 3,489 (10,255) Gross / Net Financial Instruments $ 405,976 $ (10,255) September 30, 2022 Balance Sheet Location Assets Liabilities (In thousands) Designated As Hedges: Interest rate contracts Deferred charges and other assets / $ 355,075 $ — Total 355,075 — Not Designated As Hedges: Commodity contracts Other current assets / 26,207 (3,000) Commodity contracts Deferred charges and other assets / 709 (1,129) Total 26,916 (4,129) Gross / Net Financial Instruments $ 381,991 $ (4,129) Impact of Financial Instruments on the Statement of Comprehensive Income Cash Flow Hedges As discussed above, our distribution segment has interest rate agreements, which we designated as cash flow hedges at the time the agreements were executed. The net (gain) loss on settled interest rate agreements reclassified from AOCI into interest charges on our condensed consolidated statements of comprehensive income for the three months ended June 30, 2023 and 2022 was $(0.7) million and $1.0 million and for the nine months ended June 30, 2023 and 2022 was $(2.1) million and $2.9 million. The following table summarizes the gains and losses arising from hedging transactions that were recognized as a component of other comprehensive income (loss), net of taxes, for the three and nine months ended June 30, 2023 and 2022. Three Months Ended June 30 Nine Months Ended June 30 2023 2022 2023 2022 (In thousands) Increase in fair value: Interest rate agreements $ 44,057 $ 158,993 $ 36,781 $ 233,511 Recognition of (gains) losses in earnings due to settlements: Interest rate agreements (530) 744 (1,590) 2,232 Total other comprehensive income from hedging, net of tax $ 43,527 $ 159,737 $ 35,191 $ 235,743 Deferred gains (losses) recorded in AOCI associated with our interest rate agreements are recognized in earnings as they are amortized over the terms of the underlying debt instruments. As of June 30, 2023, we had $92.6 million of net realized gains in AOCI associated with our interest rate agreements. The following amounts, net of deferred taxes, represent the expected recognition in earnings of the deferred net gains recorded in AOCI associated with our interest rate agreements, based upon the fair values of these agreements at the date of settlement. The remaining amortization periods for these settled amounts extend through fiscal 2053. However, the table below does not include the expected recognition in earnings of our outstanding interest rate swaps as those instruments have not yet settled. Interest Rate (In thousands) Next twelve months $ 2,120 Thereafter 90,437 Total $ 92,557 Financial Instruments Not Designated as Hedges As discussed above, commodity contracts which are used in our distribution segment are not designated as hedges. However, there is no earnings impact on our distribution segment as a result of the use of these financial instruments because the gains and losses arising from the use of these financial instruments are recognized in the consolidated statement of comprehensive income as a component of purchased gas cost when the related costs are recovered through our rates and recognized in revenue. Accordingly, the impact of these financial instruments is excluded from this presentation.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
Fair Value Measurements	Jun. 30, 2023
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements We report certain assets and liabilities at fair value, which is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (exit price). We record cash and cash equivalents, restricted cash and cash equivalents, accounts receivable, accounts payable, and short-term debt at carrying value, which substantially approximates fair value due to the short-term nature of these assets and liabilities. For other financial assets and liabilities, we primarily use quoted market prices and other observable market pricing information to minimize the use of unobservable pricing inputs in our measurements when determining fair value. The methods used to determine fair value for our assets and liabilities are fully described in Note 2 to the consolidated financial statements in our Annual Report on Form 10-K for the fiscal year ended September 30, 2022. During the nine months ended June 30, 2023, there were no changes in these methods. Fair value measurements also apply to the valuation of our pension and postretirement plan assets. Current accounting guidance requires employers to annually disclose information about fair value measurements of the assets of a defined benefit pension or other postretirement plan. The fair value of these assets is presented in Note 10 to the consolidated financial statements in our Annual Report on Form 10-K for the fiscal year ended September 30, 2022. Quantitative Disclosures Financial Instruments The classification of our fair value measurements requires judgment regarding the degree to which market data is observable or corroborated by observable market data. Authoritative accounting literature establishes a fair value hierarchy that prioritizes the inputs used to measure fair value based on observable and unobservable data. The hierarchy categorizes the inputs into three levels, with the highest priority given to unadjusted quoted prices in active markets for identical assets and liabilities (Level 1), with the lowest priority given to unobservable inputs (Level 3). The following tables summarize, by level within the fair value hierarchy, our assets and liabilities that were accounted for at fair value on a recurring basis as of June 30, 2023 and September 30, 2022. Assets and liabilities are categorized in their entirety based on the lowest level of input that is significant to the fair value measurement. Quoted Significant Other Observable Inputs (Level 2) (1) Significant Netting and June 30, 2023 (In thousands) Assets: Financial instruments $ — $ 405,976 $ — $ — $ 405,976 Debt and equity securities Registered investment companies 27,569 — — — 27,569 Bond mutual funds 37,267 — — — 37,267 Bonds (2) — 34,058 — — 34,058 Money market funds — 5,485 — — 5,485 Total debt and equity securities 64,836 39,543 — — 104,379 Total assets $ 64,836 $ 445,519 $ — $ — $ 510,355 Liabilities: Financial instruments $ — $ 10,255 $ — $ — $ 10,255 Quoted Significant Other Observable Inputs (Level 2) (1) Significant Netting and September 30, 2022 (In thousands) Assets: Financial instruments $ — $ 381,991 $ — $ — $ 381,991 Debt and equity securities Registered investment companies 26,367 — — — 26,367 Bond mutual funds 32,367 — — — 32,367 Bonds (2) — 33,433 — — 33,433 Money market funds — 3,845 — — 3,845 Total debt and equity securities 58,734 37,278 — — 96,012 Total assets $ 58,734 $ 419,269 $ — $ — $ 478,003 Liabilities: Financial instruments $ — $ 4,129 $ — $ — $ 4,129 (1) Our Level 2 measurements consist of over-the-counter options and swaps, which are valued using a market-based approach in which observable market prices are adjusted for criteria specific to each instrument, such as the strike price, notional amount or basis differences, municipal and corporate bonds, which are valued based on the most recent available quoted market prices and money market funds that are valued at cost. (2) Our investments in bonds are considered available-for-sale debt securities in accordance with current accounting guidance. Debt and equity securities are comprised of our available-for-sale debt securities and our equity securities. As described in Note 2 to the consolidated financial statements in our Annual Report on Form 10-K for the fiscal year ended September 30, 2022, we evaluate the performance of our available-for-sale debt securities on an investment by investment basis for impairment, taking into consideration the investment’s purpose, volatility, current returns and any intent to sell the security. As of June 30, 2023, no allowance for credit losses was recorded for our available-for-sale debt securities. At June 30, 2023 and September 30, 2022, the amortized cost of our available-for-sale debt securities was $34.6 million and $34.1 million. At June 30, 2023, we maintained investments in bonds that have contractual maturity dates ranging from July 2023 through September 2026. Other Fair Value Measures Our long-term debt is recorded at carrying value. The fair value of our long-term debt, excluding finance leases, is determined using third party market value quotations, which are considered Level 1 fair value measurements for debt instruments with a recent, observable trade or Level 2 fair value measurements for debt instruments where fair value is determined using the most recent available quoted market price. The carrying value of our finance leases materially approximates fair value. The following table presents the carrying value and fair value of our long-term debt, excluding finance leases, debt issuance costs and original issue premium or discount, as of June 30, 2023 and September 30, 2022: June 30, 2023 September 30, 2022 (In thousands) Carrying Amount $ 6,560,000 $ 7,960,000 Fair Value $ 5,760,036 $ 6,918,843

Concentration of Credit Risk

Concentration of Credit Risk	9 Months Ended
Concentration of Credit Risk	Jun. 30, 2023
Risks and Uncertainties [Abstract]
Concentration of Credit Risk	Concentration of Credit RiskInformation regarding our concentration of credit risk is disclosed in Note 17 to the consolidated financial statements in our Annual Report on Form 10-K for the fiscal year ended September 30, 2022. During the nine months ended June 30, 2023, there were no material changes in our concentration of credit risk.

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
Pay vs Performance Disclosure - USD ($) $ in Thousands	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Jun. 30, 2023	Jun. 30, 2022
Pay vs Performance Disclosure
Net income	$ 137,807	$ 357,671	$ 271,860	$ 128,547	$ 324,999	$ 249,209	$ 767,338	$ 702,755

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
Insider Trading Arrangements	Jun. 30, 2023
Trading Arrangements, by Individual
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

Unaudited Financial Informati_2

Unaudited Financial Information (Policies)	9 Months Ended
Unaudited Financial Information (Policies)	Jun. 30, 2023
Accounting Policies [Abstract]
Restricted cash and cash equivalents	Restricted cash and cash equivalents Restricted cash and cash equivalents consists of funds that are contractually or legally restricted as to usage or withdrawal and have been presented separately from cash and cash equivalents on our condensed consolidated balance sheets. Restricted cash and cash equivalents accounts were established for payment of Securitized Utility Tariff Bonds issuance costs and payment of debt service on those bonds as well as certain ongoing costs of Atmos Energy Kansas Securitization I, LLC (AEK).
Securitized intangible asset	Securitized intangible asset Our securitized intangible asset represents the Securitized Utility Tariff Property that AEK acquired from Atmos Energy in the third quarter of fiscal 2023 as part of a securitization transaction. This transaction is discussed in further detail in Notes 8 and 9 to the condensed consolidated financial statements. The securitized intangible asset is stated at cost, net of accumulated amortization, and is amortized over the life of the asset in proportion to the pattern of economic benefit based on expected future undiscounted cash flows. At the end of its life, this securitized intangible asset will have no residual value. We review amortizable intangible assets for impairment whenever events or changes in circumstances indicate that the carrying amount of such assets may not be recoverable. If such a review should indicate that the carrying amount of amortizable intangible assets is not recoverable, we reduce the carrying amount of such assets to fair value.
Regulatory assets and liabilities	Regulatory assets and liabilities Accounting principles generally accepted in the United States require cost-based, rate-regulated entities that meet certain criteria to reflect the authorized recovery of costs due to regulatory decisions in their financial statements. As a result, certain costs are permitted to be capitalized rather than expensed because they can be recovered through rates. We record certain costs as regulatory assets when future recovery through customer rates is considered probable. Regulatory liabilities are recorded when it is probable that revenues will be reduced for amounts that will be credited to customers through the ratemaking process. Substantially all of our regulatory assets are recorded as a component of other current assets and deferred charges and other assets and our regulatory liabilities are recorded as a component of other current liabilities and deferred credits and other liabilities. Deferred gas costs are recorded either in other current assets or liabilities.
Earnings per share	We use the two-class method of computing earnings per share because we have participating securities in the form of non-vested restricted stock units with a nonforfeitable right to dividend equivalents, for which vesting is predicated solely on the passage of time. The calculation of earnings per share using the two-class method excludes income attributable to these participating securities from the numerator and excludes the dilutive impact of those shares from the denominator. Basic weighted average shares outstanding is calculated based upon the weighted average number of common shares outstanding during the periods presented. Also, this calculation includes fully vested stock awards that have not yet been issued as common stock. Additionally, the weighted average shares outstanding for diluted EPS includes the incremental effects of the forward sale agreements, discussed in Note 7 to the condensed consolidated financial statements, when the impact is dilutive.
Fair value measurement	Fair Value MeasurementsWe report certain assets and liabilities at fair value, which is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (exit price). We record cash and cash equivalents, restricted cash and cash equivalents, accounts receivable, accounts payable, and short-term debt at carrying value, which substantially approximates fair value due to the short-term nature of these assets and liabilities. For other financial assets and liabilities, we primarily use quoted market prices and other observable market pricing information to minimize the use of unobservable pricing inputs in our measurements when determining fair value. The methods used to determine fair value for our assets and liabilities are fully described in Note 2 to the consolidated financial statements in our Annual Report on Form 10-K for the fiscal year ended September 30, 2022. During the nine months ended June 30, 2023, there were no changes in these methods.

Unaudited Financial Informati_3

Unaudited Financial Information (Tables)	9 Months Ended
Unaudited Financial Information (Tables)	Jun. 30, 2023
Accounting Policies [Abstract]
Schedule of Regulatory Assets	Significant regulatory assets and liabilities as of June 30, 2023 and September 30, 2022 included the following: June 30, September 30, (In thousands) Regulatory assets: Pension and postretirement benefit costs $ 22,941 $ 31,122 Infrastructure mechanisms (1) 218,999 235,972 Winter Storm Uri incremental costs (2) 32,441 2,109,454 Deferred gas costs 48,649 119,742 Regulatory excess deferred taxes (3) 47,252 47,311 Recoverable loss on reacquired debt 3,280 3,406 Deferred pipeline record collection costs 52,588 36,898 Other 16,430 21,467 $ 442,580 $ 2,605,372 Regulatory liabilities: Regulatory excess deferred taxes (3) $ 425,440 $ 545,021 Regulatory cost of removal obligation 574,098 568,307 Deferred gas costs 34,933 28,834 Asset retirement obligation 5,737 5,737 APT annual adjustment mechanism 42,797 31,138 Pension and postretirement benefit costs 141,032 156,857 Other 27,055 23,013 $ 1,251,092 $ 1,358,907 (1) Infrastructure mechanisms in Texas, Louisiana and Tennessee allow for the deferral of all eligible expenses associated with capital expenditures incurred pursuant to these rules, including the recording of interest on deferred expenses until the next rate proceeding (rate case or annual rate filing), at which time investment and costs would be recoverable through base rates. (2) Includes extraordinary gas costs incurred during Winter Storm Uri and certain related carrying costs. See Note 8 to the condensed consolidated financial statements for further information. (3) Regulatory excess deferred taxes represent changes in our net deferred tax liability related to our cost of service ratemaking due to the enactment of Tax Cuts and Jobs Act of 2017 (the "TCJA") and a Kansas legislative change enacted in fiscal 2020. See Note 12 to the condensed consolidated financial statements for further information.
Schedule of Regulatory Liabilities	Significant regulatory assets and liabilities as of June 30, 2023 and September 30, 2022 included the following: June 30, September 30, (In thousands) Regulatory assets: Pension and postretirement benefit costs $ 22,941 $ 31,122 Infrastructure mechanisms (1) 218,999 235,972 Winter Storm Uri incremental costs (2) 32,441 2,109,454 Deferred gas costs 48,649 119,742 Regulatory excess deferred taxes (3) 47,252 47,311 Recoverable loss on reacquired debt 3,280 3,406 Deferred pipeline record collection costs 52,588 36,898 Other 16,430 21,467 $ 442,580 $ 2,605,372 Regulatory liabilities: Regulatory excess deferred taxes (3) $ 425,440 $ 545,021 Regulatory cost of removal obligation 574,098 568,307 Deferred gas costs 34,933 28,834 Asset retirement obligation 5,737 5,737 APT annual adjustment mechanism 42,797 31,138 Pension and postretirement benefit costs 141,032 156,857 Other 27,055 23,013 $ 1,251,092 $ 1,358,907 (1) Infrastructure mechanisms in Texas, Louisiana and Tennessee allow for the deferral of all eligible expenses associated with capital expenditures incurred pursuant to these rules, including the recording of interest on deferred expenses until the next rate proceeding (rate case or annual rate filing), at which time investment and costs would be recoverable through base rates. (2) Includes extraordinary gas costs incurred during Winter Storm Uri and certain related carrying costs. See Note 8 to the condensed consolidated financial statements for further information. (3) Regulatory excess deferred taxes represent changes in our net deferred tax liability related to our cost of service ratemaking due to the enactment of Tax Cuts and Jobs Act of 2017 (the "TCJA") and a Kansas legislative change enacted in fiscal 2020. See Note 12 to the condensed consolidated financial statements for further information.

Segment Information (Tables)

Segment Information (Tables)	9 Months Ended
Segment Information (Tables)	Jun. 30, 2023
Segment Reporting [Abstract]
Schedule of Segment Reporting Information, by Segment	Income statements and capital expenditures for the three and nine months ended June 30, 2023 and 2022 by segment are presented in the following tables: Three Months Ended June 30, 2023 Distribution Pipeline and Storage Eliminations Consolidated (In thousands) Operating revenues from external parties $ 615,259 $ 47,474 $ — $ 662,733 Intersegment revenues 808 160,751 (161,559) — Total operating revenues 616,067 208,225 (161,559) 662,733 Purchased gas cost 206,048 (194) (161,304) 44,550 Operation and maintenance expense 138,351 56,953 (255) 195,049 Depreciation and amortization expense 107,809 42,917 — 150,726 Taxes, other than income 92,180 10,975 — 103,155 Operating income 71,679 97,574 — 169,253 Other non-operating income 6,695 9,475 — 16,170 Interest charges 16,146 15,188 — 31,334 Income before income taxes 62,228 91,861 — 154,089 Income tax expense 2,589 13,693 — 16,282 Net income $ 59,639 $ 78,168 $ — $ 137,807 Capital expenditures $ 512,585 $ 155,552 $ — $ 668,137 Three Months Ended June 30, 2022 Distribution Pipeline and Storage Eliminations Consolidated (In thousands) Operating revenues from external parties $ 772,497 $ 43,932 $ — $ 816,429 Intersegment revenues 814 139,480 (140,294) — Total operating revenues 773,311 183,412 (140,294) 816,429 Purchased gas cost 390,559 (1,347) (140,053) 249,159 Operation and maintenance expense 133,654 48,912 (241) 182,325 Depreciation and amortization expense 97,106 37,125 — 134,231 Taxes, other than income 85,933 10,194 — 96,127 Operating income 66,059 88,528 — 154,587 Other non-operating income 6,708 6,555 — 13,263 Interest charges 12,341 13,849 — 26,190 Income before income taxes 60,426 81,234 — 141,660 Income tax expense 3,025 10,088 — 13,113 Net income $ 57,401 $ 71,146 $ — $ 128,547 Capital expenditures $ 417,244 $ 118,766 $ — $ 536,010 Nine Months Ended June 30, 2023 Distribution Pipeline and Storage Eliminations Consolidated (In thousands) Operating revenues from external parties $ 3,554,389 $ 133,326 $ — $ 3,687,715 Intersegment revenues 2,314 445,952 (448,266) — Total operating revenues 3,556,703 579,278 (448,266) 3,687,715 Purchased gas cost 1,896,986 (431) (447,545) 1,449,010 Operation and maintenance expense 426,173 149,329 (721) 574,781 Depreciation and amortization expense 319,783 125,280 — 445,063 Taxes, other than income 275,002 30,782 — 305,784 Operating income 638,759 274,318 — 913,077 Other non-operating income 20,934 33,833 — 54,767 Interest charges 60,405 45,059 — 105,464 Income before income taxes 599,288 263,092 — 862,380 Income tax expense 56,707 38,335 — 95,042 Net income $ 542,581 $ 224,757 $ — $ 767,338 Capital expenditures $ 1,381,118 $ 702,368 $ — $ 2,083,486 Nine Months Ended June 30, 2022 Distribution Pipeline and Storage Eliminations Consolidated (In thousands) Operating revenues from external parties $ 3,353,800 $ 125,234 $ — $ 3,479,034 Intersegment revenues 2,479 384,843 (387,322) — Total operating revenues 3,356,279 510,077 (387,322) 3,479,034 Purchased gas cost 1,881,212 (3,075) (386,437) 1,491,700 Operation and maintenance expense 378,479 127,193 (885) 504,787 Depreciation and amortization expense 286,515 108,946 — 395,461 Taxes, other than income 242,214 29,292 — 271,506 Operating income 567,859 247,721 — 815,580 Other non-operating income 9,173 18,005 — 27,178 Interest charges 36,046 38,923 — 74,969 Income before income taxes 540,986 226,803 — 767,789 Income tax expense 35,163 29,871 — 65,034 Net income $ 505,823 $ 196,932 $ — $ 702,755 Capital expenditures $ 1,217,094 $ 508,945 $ — $ 1,726,039 Balance sheet information at June 30, 2023 and September 30, 2022 by segment is presented in the following tables: June 30, 2023 Distribution Pipeline and Storage Eliminations Consolidated (In thousands) Net property, plant and equipment $ 13,938,357 $ 5,079,984 $ — $ 19,018,341 Total assets $ 21,015,851 $ 5,369,445 $ (4,613,767) $ 21,771,529 September 30, 2022 Distribution Pipeline and Storage Eliminations Consolidated (In thousands) Net property, plant and equipment $ 12,723,532 $ 4,516,707 $ — $ 17,240,239 Total assets $ 21,424,586 $ 4,797,206 $ (4,028,803) $ 22,192,989

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
Earnings Per Share (Tables)	Jun. 30, 2023
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	Basic and diluted earnings per share for the three and nine months ended June 30, 2023 and 2022 are calculated as follows: Three Months Ended June 30 Nine Months Ended June 30 2023 2022 2023 2022 (In thousands, except per share amounts) Basic Earnings Per Share Net income $ 137,807 $ 128,547 $ 767,338 $ 702,755 Less: Income allocated to participating securities 83 79 482 465 Income available to common shareholders $ 137,724 $ 128,468 $ 766,856 $ 702,290 Basic weighted average shares outstanding 146,051 139,881 143,938 136,799 Net income per share — Basic $ 0.94 $ 0.92 $ 5.33 $ 5.13 Diluted Earnings Per Share Income available to common shareholders $ 137,724 $ 128,468 $ 766,856 $ 702,290 Effect of dilutive shares — — — — Income available to common shareholders $ 137,724 $ 128,468 $ 766,856 $ 702,290 Basic weighted average shares outstanding 146,051 139,881 143,938 136,799 Dilutive shares 16 346 60 256 Diluted weighted average shares outstanding 146,067 140,227 143,998 137,055 Net income per share — Diluted $ 0.94 $ 0.92 $ 5.33 $ 5.12

Revenue and Accounts Receivab_2

Revenue and Accounts Receivable (Tables)	9 Months Ended
Revenue and Accounts Receivable (Tables)	Jun. 30, 2023
Revenue from Contract with Customer [Abstract]
Schedule of Disaggregation of Revenue	The following tables disaggregate our revenue from contracts with customers by customer type and segment and provide a reconciliation to total operating revenues, including intersegment revenues, for the three and nine months ended June 30, 2023 and 2022. Three Months Ended June 30, 2023 Three Months Ended June 30, 2022 Distribution Pipeline and Storage Distribution Pipeline and Storage (In thousands) Gas sales revenues: Residential $ 380,099 $ — $ 441,806 $ — Commercial 165,930 — 231,309 — Industrial 23,533 — 57,045 — Public authority and other 8,562 — 13,080 — Total gas sales revenues 578,124 — 743,240 — Transportation revenues 27,988 212,322 27,216 186,405 Miscellaneous revenues 2,706 4,397 2,453 3,104 Revenues from contracts with customers 608,818 216,719 772,909 189,509 Alternative revenue program revenues (1) 6,772 (8,494) (77) (6,097) Other revenues 477 — 479 — Total operating revenues $ 616,067 $ 208,225 $ 773,311 $ 183,412 Nine Months Ended June 30, 2023 Nine Months Ended June 30, 2022 Distribution Pipeline and Storage Distribution Pipeline and Storage (In thousands) Gas sales revenues: Residential $ 2,276,240 $ — $ 2,108,349 $ — Commercial 953,409 — 910,400 — Industrial 127,792 — 160,098 — Public authority and other 54,074 — 54,668 — Total gas sales revenues 3,411,515 — 3,233,515 — Transportation revenues 93,661 597,822 87,886 514,114 Miscellaneous revenues 7,650 8,271 7,732 11,931 Revenues from contracts with customers 3,512,826 606,093 3,329,133 526,045 Alternative revenue program revenues (1) 42,360 (26,815) 25,663 (15,968) Other revenues 1,517 — 1,483 — Total operating revenues $ 3,556,703 $ 579,278 $ 3,356,279 $ 510,077 (1) In our distribution segment, we have weather-normalization adjustment mechanisms that serve to mitigate the effects of weather on our revenue. Additionally, APT has a regulatory mechanism that requires that APT shares with its tariffed customers 75% of the difference between the total non-tariffed revenues earned during a test period and a revenue benchmark.
Schedule of Allowance for Credit Loss Activity	Rollforwards of our allowance for uncollectible accounts for the three and nine months ended June 30, 2023 and 2022 are presented in the table below. The allowance excludes the gas cost portion of customers’ bills for approximately 81 percent of our customers as we have the ability to collect these gas costs through our gas cost recovery mechanisms in most of our jurisdictions. Three Months Ended June 30, 2023 (In thousands) Beginning balance, March 31, 2023 $ 52,751 Current period provisions 1,758 Write-offs charged against allowance (5,902) Recoveries of amounts previously written off 294 Ending balance, June 30, 2023 $ 48,901 Three Months Ended June 30, 2022 (In thousands) Beginning balance, March 31, 2022 $ 62,213 Current period provisions 5,657 Write-offs charged against allowance (7,430) Recoveries of amounts previously written off 328 Ending balance, June 30, 2022 $ 60,768 Nine Months Ended June 30, 2023 (In thousands) Beginning balance, September 30, 2022 $ 49,993 Current period provisions 22,000 Write-offs charged against allowance (24,656) Recoveries of amounts previously written off 1,564 Ending balance, June 30, 2023 $ 48,901 Nine Months Ended June 30, 2022 (In thousands) Beginning balance, September 30, 2021 $ 64,471 Current period provisions 17,733 Write-offs charged against allowance (22,888) Recoveries of amounts previously written off 1,452 Ending balance, June 30, 2022 $ 60,768

Debt (Tables)

Debt (Tables)	9 Months Ended
Debt (Tables)	Jun. 30, 2023
Debt Disclosure [Abstract]
Schedule of Long-term Debt Instruments	Long-term debt at June 30, 2023 and September 30, 2022 consisted of the following: June 30, 2023 September 30, 2022 (In thousands) Unsecured 0.625% Senior Notes, due March 2023 $ — $ 1,100,000 Unsecured 3.00% Senior Notes, due June 2027 500,000 500,000 Unsecured 2.625% Senior Notes, due September 2029 500,000 500,000 Unsecured 1.50% Senior Notes, due January 2031 600,000 600,000 Unsecured 5.45% Senior Notes, due October 2032 300,000 — Unsecured 5.95% Senior Notes, due October 2034 200,000 200,000 Unsecured 5.50% Senior Notes, due June 2041 400,000 400,000 Unsecured 4.15% Senior Notes, due January 2043 500,000 500,000 Unsecured 4.125% Senior Notes, due October 2044 750,000 750,000 Unsecured 4.30% Senior Notes, due October 2048 600,000 600,000 Unsecured 4.125% Senior Notes, due March 2049 450,000 450,000 Unsecured 3.375% Senior Notes, due September 2049 500,000 500,000 Unsecured 2.85% Senior Notes, due February 2052 600,000 600,000 Unsecured 5.75% Senior Notes, due October 2052 500,000 — Floating-rate Senior Notes, due March 2023 — 1,100,000 Medium-term note Series A, 1995-1, 6.67%, due December 2025 10,000 10,000 Unsecured 6.75% Debentures, due July 2028 150,000 150,000 Finance lease obligations 50,766 51,850 Total long-term debt 6,610,766 8,011,850 Less: Original issue discount on unsecured senior notes and debentures 6,188 3,704 Debt issuance cost 49,420 46,042 Current maturities of long-term debt 1,540 2,201,457 Total long-term debt, net $ 6,553,618 $ 5,760,647

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	9 Months Ended
Shareholders' Equity (Tables)	Jun. 30, 2023
Equity [Abstract]
Schedule of Reconciliation of Changes in Stockholders Equity	The following tables present a reconciliation of changes in stockholders' equity for the three and nine months ended June 30, 2023 and 2022. Common stock Additional Accumulated Retained Total Number of Stated (In thousands, except share and per share data) Balance, September 30, 2022 140,896,598 $ 704 $ 5,838,118 $ 369,112 $ 3,211,157 $ 9,419,091 Net income — — — — 271,860 271,860 Other comprehensive income — — — 22,218 — 22,218 Cash dividends ($0.74 per share) — — — — (104,552) (104,552) Common stock issued: Public and other stock offerings 2,147,210 11 223,768 — — 223,779 Stock-based compensation plans 111,953 1 3,877 — — 3,878 Balance, December 31, 2022 143,155,761 716 6,065,763 391,330 3,378,465 9,836,274 Net income — — — — 357,671 357,671 Other comprehensive loss — — — (30,333) — (30,333) Cash dividends ($0.74 per share) — — — — (106,173) (106,173) Common stock issued: Public and other stock offerings 1,316,930 6 143,808 — — 143,814 Stock-based compensation plans 11,959 — 3,952 — — 3,952 Balance, March 31, 2023 144,484,650 722 6,213,523 360,997 3,629,963 10,205,205 Net income — — — — 137,807 137,807 Other comprehensive income — — — 43,406 — 43,406 Cash dividends ($0.74 per share) — — — — (108,349) (108,349) Common stock issued: Public and other stock offerings 2,754,533 15 315,682 — — 315,697 Stock-based compensation plans 65,355 — 8,615 — — 8,615 Balance, June 30, 2023 147,304,538 $ 737 $ 6,537,820 $ 404,403 $ 3,659,421 $ 10,602,381 Common stock Additional Accumulated Retained Total Number of Stated (In thousands, except share and per share data) Balance, September 30, 2021 132,419,754 $ 662 $ 5,023,751 $ 69,803 $ 2,812,673 $ 7,906,889 Net income — — — — 249,209 249,209 Other comprehensive loss — — — (45,947) — (45,947) Cash dividends ($0.68 per share) — — — — (90,411) (90,411) Common stock issued: Public and other stock offerings 2,730,115 13 265,848 — — 265,861 Stock-based compensation plans 275,212 2 3,942 — — 3,944 Balance, December 31, 2021 135,425,081 677 5,293,541 23,856 2,971,471 8,289,545 Net income — — — — 324,999 324,999 Other comprehensive income — — — 121,723 — 121,723 Cash dividends ($0.68 per share) — — — — (93,533) (93,533) Common stock issued: Public and other stock offerings 3,509,116 18 336,451 — — 336,469 Stock-based compensation plans 77,832 — 4,028 — — 4,028 Balance, March 31, 2022 139,012,029 695 5,634,020 145,579 3,202,937 8,983,231 Net income — — — — 128,547 128,547 Other comprehensive income — — — 159,631 — 159,631 Cash dividends ($0.68 per share) — — — — (95,312) (95,312) Common stock issued: Public and other stock offerings 801,952 4 84,656 — — 84,660 Stock-based compensation plans 74,775 — 7,414 — — 7,414 Balance, June 30, 2022 139,888,756 $ 699 $ 5,726,090 $ 305,210 $ 3,236,172 $ 9,268,171
Schedule of Forward Sales Agreements	Additionally, we had $589.5 million in available proceeds from outstanding forward sale agreements, as detailed below. Maturity Shares Available Net Proceeds Available Forward Price March 28, 2024 2,099,709 $ 247,295 $ 117.78 June 28, 2024 927,939 108,946 $ 117.41 September 30, 2024 1,133,978 132,104 $ 116.50 December 31, 2024 864,175 101,138 $ 117.03 Total 5,025,801 $ 589,483 $ 117.29
Schedule of Accumulated Other Comprehensive Income (Loss)	The following tables provide the components of our accumulated other comprehensive income (loss) balances, net of the related tax effects allocated to each component of other comprehensive income (loss). Available- Interest Rate Total (In thousands) September 30, 2022 $ (495) $ 369,607 $ 369,112 Other comprehensive income before reclassifications 100 36,781 36,881 Amounts reclassified from accumulated other comprehensive income — (1,590) (1,590) Net current-period other comprehensive income 100 35,191 35,291 June 30, 2023 $ (395) $ 404,798 $ 404,403 Available- Interest Rate Total (In thousands) September 30, 2021 $ 47 $ 69,756 $ 69,803 Other comprehensive income (loss) before reclassifications (336) 233,511 233,175 Amounts reclassified from accumulated other comprehensive income — 2,232 2,232 Net current-period other comprehensive income (loss) (336) 235,743 235,407 June 30, 2022 $ (289) $ 305,499 $ 305,210

Variable Interest Entity (Table

Variable Interest Entity (Tables)	9 Months Ended
Variable Interest Entity (Tables)	Jun. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Condensed Consolidated Balance Sheet	The following table summarizes the impact of AEK on our condensed consolidated balance sheet, for the period indicated: June 30, 2023 (In thousands) Restricted cash and cash equivalents $ 1,876 Securitized intangible asset, net $ 93,600 Current maturities of securitized long-term debt $ 5,973 Securitized long-term debt $ 89,027
Schedule of Maturities of Securitized Long-term Debt	The following table summarizes the maturities of the securitized long-term debt and the amortization expense related to the securitized intangible asset expected to be recognized in our consolidated statements of comprehensive income: Maturities of Securitized Long-Term Debt Amortization Expense of Securitized Intangible Asset For the fiscal year ending: (In thousands) 2023 $ — $ 2,368 2024 9,922 8,073 2025 8,207 8,121 2026 8,635 8,545 2027 9,086 8,991 Thereafter 59,150 57,502 Total $ 95,000 $ 93,600
Schedule of Amortization Expense of Securitized Intangible Asset	The following table summarizes the maturities of the securitized long-term debt and the amortization expense related to the securitized intangible asset expected to be recognized in our consolidated statements of comprehensive income: Maturities of Securitized Long-Term Debt Amortization Expense of Securitized Intangible Asset For the fiscal year ending: (In thousands) 2023 $ — $ 2,368 2024 9,922 8,073 2025 8,207 8,121 2026 8,635 8,545 2027 9,086 8,991 Thereafter 59,150 57,502 Total $ 95,000 $ 93,600

Interim Pension and Other Pos_2

Interim Pension and Other Postretirement Benefit Plan Information (Tables)	9 Months Ended
	Jun. 30, 2023
Retirement Benefits, Description [Abstract]
Schedule of Net Benefit Costs	Three Months Ended June 30 Pension Benefits Other Benefits 2023 2022 2023 2022 (In thousands) Components of net periodic pension cost: Service cost $ 2,915 $ 4,323 $ 1,546 $ 2,559 Interest cost (1) 7,265 5,063 3,478 2,683 Expected return on assets (1) (7,278) (7,383) (2,804) (3,312) Amortization of prior service cost (credit) (1) (30) (58) (3,285) (3,308) Amortization of actuarial (gain) loss (1) 178 1,951 (1,863) — Settlements (1) 1,030 — — — Net periodic pension cost $ 4,080 $ 3,896 $ (2,928) $ (1,378) Nine Months Ended June 30 Pension Benefits Other Benefits 2023 2022 2023 2022 (In thousands) Components of net periodic pension cost: Service cost $ 8,731 $ 12,970 $ 4,637 $ 7,676 Interest cost (1) 21,915 15,190 10,433 8,050 Expected return on assets (1) (21,835) (22,149) (8,411) (9,937) Amortization of prior service cost (credit) (1) (91) (174) (9,856) (9,925) Amortization of actuarial (gain) loss (1) 506 5,853 (5,589) — Settlements (1) 1,030 — — — Net periodic pension cost $ 10,256 $ 11,690 $ (8,786) $ (4,136) (1) The components of net periodic cost other than the service cost component are included in the line item other non-operating expense in the condensed consolidated statements of comprehensive income or are capitalized on the condensed consolidated balance sheets as a regulatory asset or liability, as described in Note 2 to the consolidated financial statements in our Annual Report on Form 10-K for the fiscal year ended September 30, 2022.

Financial Instruments (Tables)

Financial Instruments (Tables)	9 Months Ended
Financial Instruments (Tables)	Jun. 30, 2023
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Interest Rate Derivatives	The following table summarizes our existing forward starting interest rate swaps as of June 30, 2023. Planned Debt Issuance Date Amount Hedged (In thousands) Fiscal 2024 $ 700,000 Fiscal 2025 600,000 Fiscal 2026 300,000 $ 1,600,000
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value	The following tables present the fair value and balance sheet classification of our financial instruments as of June 30, 2023 and September 30, 2022. The gross amounts of recognized assets and liabilities are netted within our condensed consolidated balance sheets to the extent that we have netting arrangements with our counterparties. However, as of June 30, 2023 and September 30, 2022, no gross amounts and no cash collateral were netted within our consolidated balance sheet. June 30, 2023 Balance Sheet Location Assets Liabilities (In thousands) Designated As Hedges: Interest rate contracts Other current assets / $ 123,716 $ — Interest rate contracts Deferred charges and other assets / 278,771 — Total 402,487 — Not Designated As Hedges: Commodity contracts Other current assets / 2,811 (9,752) Commodity contracts Deferred charges and other assets / 678 (503) Total 3,489 (10,255) Gross / Net Financial Instruments $ 405,976 $ (10,255) September 30, 2022 Balance Sheet Location Assets Liabilities (In thousands) Designated As Hedges: Interest rate contracts Deferred charges and other assets / $ 355,075 $ — Total 355,075 — Not Designated As Hedges: Commodity contracts Other current assets / 26,207 (3,000) Commodity contracts Deferred charges and other assets / 709 (1,129) Total 26,916 (4,129) Gross / Net Financial Instruments $ 381,991 $ (4,129)
Schedule of Cash Flow Hedges Included in Accumulated Other Comprehensive Income (Loss)	The following table summarizes the gains and losses arising from hedging transactions that were recognized as a component of other comprehensive income (loss), net of taxes, for the three and nine months ended June 30, 2023 and 2022. Three Months Ended June 30 Nine Months Ended June 30 2023 2022 2023 2022 (In thousands) Increase in fair value: Interest rate agreements $ 44,057 $ 158,993 $ 36,781 $ 233,511 Recognition of (gains) losses in earnings due to settlements: Interest rate agreements (530) 744 (1,590) 2,232 Total other comprehensive income from hedging, net of tax $ 43,527 $ 159,737 $ 35,191 $ 235,743
Schedule of Expected Deferred Gains (Losses) Recognition	The following amounts, net of deferred taxes, represent the expected recognition in earnings of the deferred net gains recorded in AOCI associated with our interest rate agreements, based upon the fair values of these agreements at the date of settlement. The remaining amortization periods for these settled amounts extend through fiscal 2053. However, the table below does not include the expected recognition in earnings of our outstanding interest rate swaps as those instruments have not yet settled. Interest Rate (In thousands) Next twelve months $ 2,120 Thereafter 90,437 Total $ 92,557

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
Fair Value Measurements (Tables)	Jun. 30, 2023
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The following tables summarize, by level within the fair value hierarchy, our assets and liabilities that were accounted for at fair value on a recurring basis as of June 30, 2023 and September 30, 2022. Assets and liabilities are categorized in their entirety based on the lowest level of input that is significant to the fair value measurement. Quoted Significant Other Observable Inputs (Level 2) (1) Significant Netting and June 30, 2023 (In thousands) Assets: Financial instruments $ — $ 405,976 $ — $ — $ 405,976 Debt and equity securities Registered investment companies 27,569 — — — 27,569 Bond mutual funds 37,267 — — — 37,267 Bonds (2) — 34,058 — — 34,058 Money market funds — 5,485 — — 5,485 Total debt and equity securities 64,836 39,543 — — 104,379 Total assets $ 64,836 $ 445,519 $ — $ — $ 510,355 Liabilities: Financial instruments $ — $ 10,255 $ — $ — $ 10,255 Quoted Significant Other Observable Inputs (Level 2) (1) Significant Netting and September 30, 2022 (In thousands) Assets: Financial instruments $ — $ 381,991 $ — $ — $ 381,991 Debt and equity securities Registered investment companies 26,367 — — — 26,367 Bond mutual funds 32,367 — — — 32,367 Bonds (2) — 33,433 — — 33,433 Money market funds — 3,845 — — 3,845 Total debt and equity securities 58,734 37,278 — — 96,012 Total assets $ 58,734 $ 419,269 $ — $ — $ 478,003 Liabilities: Financial instruments $ — $ 4,129 $ — $ — $ 4,129 (1) Our Level 2 measurements consist of over-the-counter options and swaps, which are valued using a market-based approach in which observable market prices are adjusted for criteria specific to each instrument, such as the strike price, notional amount or basis differences, municipal and corporate bonds, which are valued based on the most recent available quoted market prices and money market funds that are valued at cost. (2) Our investments in bonds are considered available-for-sale debt securities in accordance with current accounting guidance.
Schedule of Carrying Values and Estimated Fair Values of Long-Term Debt	The following table presents the carrying value and fair value of our long-term debt, excluding finance leases, debt issuance costs and original issue premium or discount, as of June 30, 2023 and September 30, 2022: June 30, 2023 September 30, 2022 (In thousands) Carrying Amount $ 6,560,000 $ 7,960,000 Fair Value $ 5,760,036 $ 6,918,843

Nature of Business (Details)

Nature of Business (Details) customer in Millions	Jun. 30, 2023 regulatedDistributionDivision customer state
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of customers serviced \| customer	3.3
Number of regulated distribution divisions \| regulatedDistributionDivision	6
Number of states with service areas \| state	8

Unaudited Financial Informati_4

Unaudited Financial Information - Regulatory Assets and Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Sep. 30, 2022
Regulatory Asset [Line Items]
Regulatory assets	$ 442,580	$ 2,605,372
Regulatory Liabilities [Line Items]
Regulatory liabilities	1,251,092	1,358,907
Regulatory excess deferred taxes
Regulatory Liabilities [Line Items]
Regulatory liabilities	425,440	545,021
Regulatory cost of removal obligation
Regulatory Liabilities [Line Items]
Regulatory liabilities	574,098	568,307
Deferred gas costs
Regulatory Liabilities [Line Items]
Regulatory liabilities	34,933	28,834
Asset retirement obligation
Regulatory Liabilities [Line Items]
Regulatory liabilities	5,737	5,737
APT annual adjustment mechanism
Regulatory Liabilities [Line Items]
Regulatory liabilities	42,797	31,138
Pension and postretirement benefit costs
Regulatory Liabilities [Line Items]
Regulatory liabilities	141,032	156,857
Other
Regulatory Liabilities [Line Items]
Regulatory liabilities	27,055	23,013
Pension and postretirement benefit costs
Regulatory Asset [Line Items]
Regulatory assets	22,941	31,122
Infrastructure mechanisms
Regulatory Asset [Line Items]
Regulatory assets	218,999	235,972
Winter Storm Uri incremental costs
Regulatory Asset [Line Items]
Regulatory assets	32,441	2,109,454
Deferred gas costs
Regulatory Asset [Line Items]
Regulatory assets	48,649	119,742
Regulatory excess deferred taxes
Regulatory Asset [Line Items]
Regulatory assets	47,252	47,311
Recoverable loss on reacquired debt
Regulatory Asset [Line Items]
Regulatory assets	3,280	3,406
Deferred pipeline record collection costs
Regulatory Asset [Line Items]
Regulatory assets	52,588	36,898
Other
Regulatory Asset [Line Items]
Regulatory assets	$ 16,430	$ 21,467

Segment Information (Details)

Segment Information (Details) $ in Thousands	3 Months Ended						9 Months Ended
Segment Information (Details) $ in Thousands	Jun. 30, 2023 USD ($) state	Mar. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Jun. 30, 2022 USD ($)	Mar. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Jun. 30, 2023 USD ($) state	Jun. 30, 2022 USD ($)	Sep. 30, 2022 USD ($)
Segment Reporting Information [Line Items]
Number of states with service areas \| state	8						8
Segment Reporting Information Profit Loss [Abstract]
Operating revenues	$ 662,733			$ 816,429			$ 3,687,715	$ 3,479,034
Purchased gas cost	44,550			249,159			1,449,010	1,491,700
Operation and maintenance expense	195,049			182,325			574,781	504,787
Depreciation and amortization expense	150,726			134,231			445,063	395,461
Taxes, other than income	103,155			96,127			305,784	271,506
Operating income	169,253			154,587			913,077	815,580
Other non-operating income	16,170			13,263			54,767	27,178
Interest charges	31,334			26,190			105,464	74,969
Income before income taxes	154,089			141,660			862,380	767,789
Income tax expense	16,282			13,113			95,042	65,034
Net income	137,807	$ 357,671	$ 271,860	128,547	$ 324,999	$ 249,209	767,338	702,755
Capital expenditures	668,137			536,010			2,083,486	1,726,039
Segment Reporting Information, Balance Sheet [Abstract]
Net property, plant and equipment	19,018,341						19,018,341		$ 17,240,239
Total assets	21,771,529						21,771,529		22,192,989
Distribution
Segment Reporting Information Profit Loss [Abstract]
Operating revenues	615,259			772,497			3,554,389	3,353,800
Pipeline and Storage
Segment Reporting Information Profit Loss [Abstract]
Operating revenues	47,474			43,932			133,326	125,234
Eliminations
Segment Reporting Information Profit Loss [Abstract]
Operating revenues	(161,559)			(140,294)			(448,266)	(387,322)
Purchased gas cost	(161,304)			(140,053)			(447,545)	(386,437)
Operation and maintenance expense	(255)			(241)			(721)	(885)
Depreciation and amortization expense	0			0			0	0
Taxes, other than income	0			0			0	0
Operating income	0			0			0	0
Other non-operating income	0			0			0	0
Interest charges	0			0			0	0
Income before income taxes	0			0			0	0
Income tax expense	0			0			0	0
Net income	0			0			0	0
Capital expenditures	0			0			0	0
Segment Reporting Information, Balance Sheet [Abstract]
Net property, plant and equipment	0						0		0
Total assets	(4,613,767)						(4,613,767)		(4,028,803)
Eliminations \| Distribution
Segment Reporting Information Profit Loss [Abstract]
Operating revenues	808			814			2,314	2,479
Eliminations \| Pipeline and Storage
Segment Reporting Information Profit Loss [Abstract]
Operating revenues	160,751			139,480			445,952	384,843
Operating Segments \| Distribution
Segment Reporting Information Profit Loss [Abstract]
Operating revenues	616,067			773,311			3,556,703	3,356,279
Purchased gas cost	206,048			390,559			1,896,986	1,881,212
Operation and maintenance expense	138,351			133,654			426,173	378,479
Depreciation and amortization expense	107,809			97,106			319,783	286,515
Taxes, other than income	92,180			85,933			275,002	242,214
Operating income	71,679			66,059			638,759	567,859
Other non-operating income	6,695			6,708			20,934	9,173
Interest charges	16,146			12,341			60,405	36,046
Income before income taxes	62,228			60,426			599,288	540,986
Income tax expense	2,589			3,025			56,707	35,163
Net income	59,639			57,401			542,581	505,823
Capital expenditures	512,585			417,244			1,381,118	1,217,094
Segment Reporting Information, Balance Sheet [Abstract]
Net property, plant and equipment	13,938,357						13,938,357		12,723,532
Total assets	21,015,851						21,015,851		21,424,586
Operating Segments \| Pipeline and Storage
Segment Reporting Information Profit Loss [Abstract]
Operating revenues	208,225			183,412			579,278	510,077
Purchased gas cost	(194)			(1,347)			(431)	(3,075)
Operation and maintenance expense	56,953			48,912			149,329	127,193
Depreciation and amortization expense	42,917			37,125			125,280	108,946
Taxes, other than income	10,975			10,194			30,782	29,292
Operating income	97,574			88,528			274,318	247,721
Other non-operating income	9,475			6,555			33,833	18,005
Interest charges	15,188			13,849			45,059	38,923
Income before income taxes	91,861			81,234			263,092	226,803
Income tax expense	13,693			10,088			38,335	29,871
Net income	78,168			71,146			224,757	196,932
Capital expenditures	155,552			$ 118,766			702,368	$ 508,945
Segment Reporting Information, Balance Sheet [Abstract]
Net property, plant and equipment	5,079,984						5,079,984		4,516,707
Total assets	$ 5,369,445						$ 5,369,445		$ 4,797,206

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended						9 Months Ended
	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Jun. 30, 2023	Jun. 30, 2022
Basic Earnings Per Share
Net income	$ 137,807	$ 357,671	$ 271,860	$ 128,547	$ 324,999	$ 249,209	$ 767,338	$ 702,755
Less: Income allocated to participating securities	83			79			482	465
Income available to common shareholders	$ 137,724			$ 128,468			$ 766,856	$ 702,290
Basic weighted average shares outstanding (in shares)	146,051			139,881			143,938	136,799
Net income per share - Basic (USD per share)	$ 0.94			$ 0.92			$ 5.33	$ 5.13
Diluted Earnings Per Share
Income available to common shareholders	$ 137,724			$ 128,468			$ 766,856	$ 702,290
Effect of dilutive shares	0			0			0	0
Income available to common shareholders	$ 137,724			$ 128,468			$ 766,856	$ 702,290
Basic weighted average shares outstanding (in shares)	146,051			139,881			143,938	136,799
Dilutive shares (in shares)	16			346			60	256
Diluted weighted average shares outstanding (in shares)	146,067			140,227			143,998	137,055
Net income per share - Diluted (USD per share)	$ 0.94			$ 0.92			$ 5.33	$ 5.12

Revenue and Accounts Receivab_3

Revenue and Accounts Receivable - Disaggregation (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Disaggregation of Revenue [Line Items]
Total operating revenues	$ 662,733	$ 816,429	$ 3,687,715	$ 3,479,034
Distribution
Disaggregation of Revenue [Line Items]
Total operating revenues	$ 615,259	$ 772,497	$ 3,554,389	$ 3,353,800
Regulatory mechanism threshold (in percent)	75%	75%	75%	75%
Pipeline and Storage
Disaggregation of Revenue [Line Items]
Total operating revenues	$ 47,474	$ 43,932	$ 133,326	$ 125,234
Operating Segments \| Distribution
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	608,818	772,909	3,512,826	3,329,133
Alternative revenue program revenues	6,772	(77)	42,360	25,663
Other revenues	477	479	1,517	1,483
Total operating revenues	616,067	773,311	3,556,703	3,356,279
Operating Segments \| Distribution \| Gas sales revenues
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	578,124	743,240	3,411,515	3,233,515
Operating Segments \| Distribution \| Gas sales revenues \| Residential
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	380,099	441,806	2,276,240	2,108,349
Operating Segments \| Distribution \| Gas sales revenues \| Commercial
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	165,930	231,309	953,409	910,400
Operating Segments \| Distribution \| Gas sales revenues \| Industrial
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	23,533	57,045	127,792	160,098
Operating Segments \| Distribution \| Gas sales revenues \| Public authority and other
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	8,562	13,080	54,074	54,668
Operating Segments \| Distribution \| Transportation revenues
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	27,988	27,216	93,661	87,886
Operating Segments \| Distribution \| Miscellaneous revenues
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	2,706	2,453	7,650	7,732
Operating Segments \| Pipeline and Storage
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	216,719	189,509	606,093	526,045
Alternative revenue program revenues	(8,494)	(6,097)	(26,815)	(15,968)
Other revenues	0	0	0	0
Total operating revenues	208,225	183,412	579,278	510,077
Operating Segments \| Pipeline and Storage \| Gas sales revenues
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0	0	0	0
Operating Segments \| Pipeline and Storage \| Gas sales revenues \| Residential
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0	0	0	0
Operating Segments \| Pipeline and Storage \| Gas sales revenues \| Commercial
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0	0	0	0
Operating Segments \| Pipeline and Storage \| Gas sales revenues \| Industrial
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0	0	0	0
Operating Segments \| Pipeline and Storage \| Gas sales revenues \| Public authority and other
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0	0	0	0
Operating Segments \| Pipeline and Storage \| Transportation revenues
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	212,322	186,405	597,822	514,114
Operating Segments \| Pipeline and Storage \| Miscellaneous revenues
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	$ 4,397	$ 3,104	$ 8,271	$ 11,931

Revenue and Accounts Receivab_4

Revenue and Accounts Receivable - Allowance for Credit Loss (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Revenue from Contract with Customer [Abstract]
Percent of customers excluded	81%	81%	81%	81%
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 52,751	$ 62,213	$ 49,993	$ 64,471
Current period provisions	1,758	5,657	22,000	17,733
Write-offs charged against allowance	(5,902)	(7,430)	(24,656)	(22,888)
Recoveries of amounts previously written off	294	328	1,564	1,452
Ending balance	$ 48,901	$ 60,768	$ 48,901	$ 60,768

Debt - Schedule of Long-term De

Debt - Schedule of Long-term Debt Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Sep. 30, 2022
Debt Instrument [Line Items]
Long-term debt	$ 6,560,000	$ 7,960,000
Finance lease obligations	50,766	51,850
Total long-term debt	6,610,766	8,011,850
Less:
Original issue discount on unsecured senior notes and debentures	6,188	3,704
Debt issuance cost	49,420	46,042
Current maturities of long-term debt	1,540	2,201,457
Long-term debt, net	$ 6,553,618	5,760,647
Unsecured 0.625% Senior Notes, due March 2023
Debt Instrument [Line Items]
Interest rate	0.625%
Long-term debt	$ 0	1,100,000
Unsecured 3.00% Senior Notes, due June 2027
Debt Instrument [Line Items]
Interest rate	3%
Long-term debt	$ 500,000	500,000
Unsecured 2.625% Senior Notes, due September 2029
Debt Instrument [Line Items]
Interest rate	2.625%
Long-term debt	$ 500,000	500,000
Unsecured 1.50% Senior Notes, due January 2031
Debt Instrument [Line Items]
Interest rate	1.50%
Long-term debt	$ 600,000	600,000
Unsecured 5.45% Senior Notes, due October 2032
Debt Instrument [Line Items]
Interest rate	5.45%
Long-term debt	$ 300,000	0
Unsecured 5.95% Senior Notes, due October 2034
Debt Instrument [Line Items]
Interest rate	5.95%
Long-term debt	$ 200,000	200,000
Unsecured 5.50% Senior Notes, due June 2041
Debt Instrument [Line Items]
Interest rate	5.50%
Long-term debt	$ 400,000	400,000
Unsecured 4.15% Senior Notes, due January 2043
Debt Instrument [Line Items]
Interest rate	4.15%
Long-term debt	$ 500,000	500,000
Unsecured 4.125% Senior Notes, due October 2044
Debt Instrument [Line Items]
Interest rate	4.125%
Long-term debt	$ 750,000	750,000
Unsecured 4.30% Senior Notes, due October 2048
Debt Instrument [Line Items]
Interest rate	4.30%
Long-term debt	$ 600,000	600,000
Unsecured 4.125% Senior Notes, due March 2049
Debt Instrument [Line Items]
Interest rate	4.125%
Long-term debt	$ 450,000	450,000
Unsecured 3.375% Senior Notes, due September 2049
Debt Instrument [Line Items]
Interest rate	3.375%
Long-term debt	$ 500,000	500,000
Unsecured 2.85% Senior Notes, due February 2052
Debt Instrument [Line Items]
Interest rate	2.85%
Long-term debt	$ 600,000	600,000
Unsecured 5.75% Senior Notes, due October 2052
Debt Instrument [Line Items]
Interest rate	5.75%
Long-term debt	$ 500,000	0
Floating-rate Senior Notes, due March 2023
Debt Instrument [Line Items]
Long-term debt	$ 0	1,100,000
Medium-term note Series A, 1995-1, 6.67%, due December 2025
Debt Instrument [Line Items]
Interest rate	6.67%
Long-term debt	$ 10,000	10,000
Unsecured 6.75% Debentures, due July 2028
Debt Instrument [Line Items]
Interest rate	6.75%
Long-term debt	$ 150,000	$ 150,000

Debt - Narrative (Details)

Debt - Narrative (Details)				9 Months Ended
Debt - Narrative (Details)	Mar. 09, 2023 USD ($)	Mar. 03, 2023 USD ($)	Oct. 03, 2022 USD ($)	Jun. 30, 2023 USD ($) creditFacility	Jun. 30, 2022 USD ($)	Sep. 30, 2022 USD ($)	Mar. 31, 2021 USD ($)
Line Of Credit Facility [Line Items]
Proceeds from issuance of long-term debt				$ 797,258,000	$ 798,802,000
Repayment of long-term debt				$ 2,200,000,000	$ 200,000,000
Maximum debt-to-total-capitalization ratio				70%
Debt-to-total-capitalization ratio				0.39
Revolving Credit Facility
Line Of Credit Facility [Line Items]
Maximum borrowing capacity				$ 2,500,000,000
Number of credit facilities \| creditFacility				4
Minimum
Line Of Credit Facility [Line Items]
Outstanding indebtedness				$ 15,000,000
Maximum
Line Of Credit Facility [Line Items]
Outstanding indebtedness				100,000,000
Senior Notes
Line Of Credit Facility [Line Items]
Debt instrument, face amount							$ 2,200,000,000
Repayment of long-term debt		$ 2,200,000,000
Unsecured Debt \| Line of Credit
Line Of Credit Facility [Line Items]
Repayment of long-term debt	$ 1,100,000,000
Unsecured Senior Notes Due October 2052 \| Senior Notes
Line Of Credit Facility [Line Items]
Debt instrument, face amount			$ 500,000,000
Interest rate			5.75%
Effective interest rate			4.50%
Unsecured Senior Notes Due October 2032 \| Senior Notes
Line Of Credit Facility [Line Items]
Debt instrument, face amount			$ 300,000,000
Interest rate			5.45%
Effective interest rate			5.57%
Unsecured Senior Notes Due Octpber 2032 and Unsecured Senior Notes Due October 2052 \| Senior Notes
Line Of Credit Facility [Line Items]
Proceeds from issuance of long-term debt			$ 789,400,000
Five Year Unsecured Revolving Credit Agreement
Line Of Credit Facility [Line Items]
Outstanding commercial paper				0		$ 185,000,000
Five Year Unsecured Revolving Credit Agreement \| Commercial Paper
Line Of Credit Facility [Line Items]
Maximum borrowing capacity				$ 1,500,000,000
Debt agreement term				5 years
Accordion feature				$ 250,000,000
Maximum borrowing capacity post accordion feature				$ 1,750,000,000
Five Year Unsecured Revolving Credit Agreement \| Minimum \| Base Rate
Line Of Credit Facility [Line Items]
Interest rate spread				0%
Five Year Unsecured Revolving Credit Agreement \| Minimum \| SOFR
Line Of Credit Facility [Line Items]
Interest rate spread				0.75%
Five Year Unsecured Revolving Credit Agreement \| Maximum \| Base Rate
Line Of Credit Facility [Line Items]
Interest rate spread				0.25%
Five Year Unsecured Revolving Credit Agreement \| Maximum \| SOFR
Line Of Credit Facility [Line Items]
Interest rate spread				1.25%
$900 Million Revolving Credit Facility \| Revolving Credit Facility
Line Of Credit Facility [Line Items]
Maximum borrowing capacity				$ 900,000,000
Debt agreement term				3 years
Accordion feature				$ 100,000,000
Maximum borrowing capacity post accordion feature				1,000,000,000
Outstanding borrowings				$ 0		0
$900 Million Revolving Credit Facility \| Minimum \| Revolving Credit Facility \| Base Rate
Line Of Credit Facility [Line Items]
Interest rate spread				0%
$900 Million Revolving Credit Facility \| Minimum \| Revolving Credit Facility \| SOFR
Line Of Credit Facility [Line Items]
Interest rate spread				0.75%
$900 Million Revolving Credit Facility \| Maximum \| Revolving Credit Facility \| Base Rate
Line Of Credit Facility [Line Items]
Interest rate spread				0.25%
$900 Million Revolving Credit Facility \| Maximum \| Revolving Credit Facility \| SOFR
Line Of Credit Facility [Line Items]
Interest rate spread				1.25%
$50 Million Bank Loan Agreement \| Line of Credit
Line Of Credit Facility [Line Items]
Maximum borrowing capacity				$ 50,000,000
Debt agreement term				364 days
Outstanding borrowings				$ 0		$ 0
$50 Million Revolving Credit Facility
Line Of Credit Facility [Line Items]
Outstanding borrowings				0
$50 Million Revolving Credit Facility \| Revolving Credit Facility
Line Of Credit Facility [Line Items]
Maximum borrowing capacity				$ 50,000,000
Debt agreement term				364 days
Remaining borrowing capacity				$ 44,400,000
Unsecured Senior Term Loan Due 2023 \| Unsecured Debt \| Line of Credit
Line Of Credit Facility [Line Items]
Debt instrument, face amount		$ 2,020,000,000
Floating Rate Senior Notes \| Unsecured Debt \| Line of Credit
Line Of Credit Facility [Line Items]
Repayment of long-term debt	$ 1,100,000,000

Shareholders' Equity - Componen

Shareholders' Equity - Components of Equity (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended
	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Jun. 30, 2023	Jun. 30, 2022
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock outstanding, beginning balance (in shares)			140,896,598				140,896,598
Shareholders' equity, beginning balance	$ 10,205,205	$ 9,836,274	$ 9,419,091	$ 8,983,231	$ 8,289,545	$ 7,906,889	$ 9,419,091	$ 7,906,889
Net income	137,807	357,671	271,860	128,547	324,999	249,209	$ 767,338	702,755
Other comprehensive income (loss)	43,406	(30,333)	22,218	159,631	121,723	(45,947)
Cash dividends	(108,349)	(106,173)	(104,552)	(95,312)	(93,533)	(90,411)
Public and other stock offerings	315,697	143,814	223,779	84,660	336,469	265,861
Stock-based compensation plans	$ 8,615	3,952	3,878	7,414	4,028	3,944
Common stock outstanding, ending balance (in shares)	147,304,538						147,304,538
Shareholders' equity, ending balance	$ 10,602,381	$ 10,205,205	$ 9,836,274	$ 9,268,171	$ 8,983,231	$ 8,289,545	$ 10,602,381	$ 9,268,171
Cash dividends per share (USD per share)	$ 0.74	$ 0.74	$ 0.74	$ 0.68	$ 0.68	$ 0.68	$ 2.22	$ 2.04
Common stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock outstanding, beginning balance (in shares)	144,484,650	143,155,761	140,896,598	139,012,029	135,425,081	132,419,754	140,896,598	132,419,754
Shareholders' equity, beginning balance	$ 722	$ 716	$ 704	$ 695	$ 677	$ 662	$ 704	$ 662
Public and other stock offerings (in shares)	2,754,533	1,316,930	2,147,210	801,952	3,509,116	2,730,115
Public and other stock offerings	$ 15	$ 6	$ 11	$ 4	$ 18	$ 13
Stock-based compensation plans (in shares)	65,355	11,959	111,953	74,775	77,832	275,212
Stock-based compensation plans			$ 1			$ 2
Common stock outstanding, ending balance (in shares)	147,304,538	144,484,650	143,155,761	139,888,756	139,012,029	135,425,081	147,304,538	139,888,756
Shareholders' equity, ending balance	$ 737	$ 722	$ 716	$ 699	$ 695	$ 677	$ 737	$ 699
Additional Paid-in Capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shareholders' equity, beginning balance	6,213,523	6,065,763	5,838,118	5,634,020	5,293,541	5,023,751	5,838,118	5,023,751
Public and other stock offerings	315,682	143,808	223,768	84,656	336,451	265,848
Stock-based compensation plans	8,615	3,952	3,877	7,414	4,028	3,942
Shareholders' equity, ending balance	6,537,820	6,213,523	6,065,763	5,726,090	5,634,020	5,293,541	6,537,820	5,726,090
Accumulated Other Comprehensive Income (Loss)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shareholders' equity, beginning balance	360,997	391,330	369,112	145,579	23,856	69,803	369,112	69,803
Other comprehensive income (loss)	43,406	(30,333)	22,218	159,631	121,723	(45,947)
Shareholders' equity, ending balance	404,403	360,997	391,330	305,210	145,579	23,856	404,403	305,210
Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shareholders' equity, beginning balance	3,629,963	3,378,465	3,211,157	3,202,937	2,971,471	2,812,673	3,211,157	2,812,673
Net income	137,807	357,671	271,860	128,547	324,999	249,209
Cash dividends	(108,349)	(106,173)	(104,552)	(95,312)	(93,533)	(90,411)
Shareholders' equity, ending balance	$ 3,659,421	$ 3,629,963	$ 3,378,465	$ 3,236,172	$ 3,202,937	$ 2,971,471	$ 3,659,421	$ 3,236,172

Shareholders' Equity - Narrativ

Shareholders' Equity - Narrative (Details) - USD ($)	9 Months Ended
Shareholders' Equity - Narrative (Details) - USD ($)	Jun. 30, 2023	Jun. 30, 2022	Mar. 31, 2023
Class of Stock [Line Items]
Net proceeds available	$ 589,483,000
Net proceeds from equity issuances	671,630,000	$ 675,320,000
Shelf Registration Statement
Class of Stock [Line Items]
Debt and equity securities authorized for issuance			$ 5,000,000,000
Debt and equity securities authorized for issuance value remaining	4,000,000,000
At-The-Market
Class of Stock [Line Items]
Equity authorized	$ 1,000,000,000
Forward sales equity agreement (in shares)	4,116,489
Net proceeds available	$ 485,700,000
Stock issued during period, new issues (in shares)	6,116,848
Net proceeds from equity issuances	$ 671,600,000
Equity available for issuance	$ 771,300,000

Shareholders' Equity - Forward

Shareholders' Equity - Forward Sales Agreement (Details) $ / shares in Units, $ in Thousands	9 Months Ended
	Jun. 30, 2023 USD ($) $ / shares shares
Forward Contract Indexed to Issuer's Equity [Line Items]
Shares available (in shares) \| shares	5,025,801
Net proceeds available \| $	$ 589,483
Forward price (USD per share) \| $ / shares	$ 117.29
Forward Sales Equity Agreement Maturing Quarter Ended March 28, 2024
Forward Contract Indexed to Issuer's Equity [Line Items]
Shares available (in shares) \| shares	2,099,709
Net proceeds available \| $	$ 247,295
Forward price (USD per share) \| $ / shares	$ 117.78
Forward Sales Equity Agreement Maturing Quarter Ended June 28, 2024
Forward Contract Indexed to Issuer's Equity [Line Items]
Shares available (in shares) \| shares	927,939
Net proceeds available \| $	$ 108,946
Forward price (USD per share) \| $ / shares	$ 117.41
Forward Sales Equity Agreement Maturing Quarter Ended September 30 2024
Forward Contract Indexed to Issuer's Equity [Line Items]
Shares available (in shares) \| shares	1,133,978
Net proceeds available \| $	$ 132,104
Forward price (USD per share) \| $ / shares	$ 116.50
Forward Sales Equity Agreement Maturing Quarter Ended December 31 2024
Forward Contract Indexed to Issuer's Equity [Line Items]
Shares available (in shares) \| shares	864,175
Net proceeds available \| $	$ 101,138
Forward price (USD per share) \| $ / shares	$ 117.03

Shareholders' Equity - Schedule

Shareholders' Equity - Schedule of AOCI (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Shareholders' equity, beginning balance	$ 10,205,205	$ 8,983,231	$ 9,419,091	$ 7,906,889
Other comprehensive income (loss) before reclassifications			36,881	233,175
Amounts reclassified from accumulated other comprehensive income			(1,590)	2,232
Net current-period other comprehensive income (loss)	43,406	159,631	35,291	235,407
Shareholders' equity, ending balance	10,602,381	9,268,171	10,602,381	9,268,171
Available- for-Sale Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Shareholders' equity, beginning balance			(495)	47
Other comprehensive income (loss) before reclassifications			100	(336)
Amounts reclassified from accumulated other comprehensive income			0	0
Net current-period other comprehensive income (loss)			100	(336)
Shareholders' equity, ending balance	(395)	(289)	(395)	(289)
Interest Rate Agreement Cash Flow Hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Shareholders' equity, beginning balance			369,607	69,756
Other comprehensive income (loss) before reclassifications			36,781	233,511
Amounts reclassified from accumulated other comprehensive income			(1,590)	2,232
Net current-period other comprehensive income (loss)			35,191	235,743
Shareholders' equity, ending balance	404,798	305,499	404,798	305,499
Accumulated Other Comprehensive Income (Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Shareholders' equity, beginning balance	360,997	145,579	369,112	69,803
Shareholders' equity, ending balance	$ 404,403	$ 305,210	$ 404,403	$ 305,210

Winter Storm Uri (Details)

Winter Storm Uri (Details) - USD ($)					1 Months Ended	9 Months Ended		10 Months Ended
Winter Storm Uri (Details) - USD ($)	Jun. 20, 2023	Mar. 23, 2023	Mar. 09, 2023	Mar. 03, 2023	Feb. 28, 2021	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Mar. 31, 2021
Unusual or Infrequent Item, or Both [Line Items]
Aggregate natural gas purchases					$ 2,300,000,000
Repayment of senior notes						$ 2,200,000,000	$ 200,000,000
Securitized Utility Tariff Property \| AEK
Unusual or Infrequent Item, or Both [Line Items]
Proceeds from sale of intangible assets	$ 92,300,000
Winter Storm Uri incremental costs \| Winter Storm Uri \| Kansas
Unusual or Infrequent Item, or Both [Line Items]
Regulatory asset, relieved	92,300,000
Winter Storm Uri incremental costs \| Winter Storm Uri \| Texas
Unusual or Infrequent Item, or Both [Line Items]
Regulatory asset, deferred costs								$ 32,400,000
Extraordinary Gas Cost \| Winter Storm Uri \| Texas
Unusual or Infrequent Item, or Both [Line Items]
Regulatory asset, relieved		$ 2,020,000,000
Regulatory asset, authorized		3,500,000,000
Proceeds from customer rate relief bonds		$ 2,020,000,000
Extraordinary Gas Cost \| Winter Storm Uri \| Texas \| Minimum
Unusual or Infrequent Item, or Both [Line Items]
Regulatory asset, maturity period		12 years
Extraordinary Gas Cost \| Winter Storm Uri \| Texas \| Maximum
Unusual or Infrequent Item, or Both [Line Items]
Regulatory asset, maturity period		18 years
Senior Notes
Unusual or Infrequent Item, or Both [Line Items]
Debt instrument, face amount									$ 2,200,000,000
Repayment of senior notes				$ 2,200,000,000
Unsecured Debt \| Line of Credit
Unusual or Infrequent Item, or Both [Line Items]
Repayment of senior notes			$ 1,100,000,000
Unsecured Senior Term Loan Due 2023 \| Unsecured Debt \| Line of Credit
Unusual or Infrequent Item, or Both [Line Items]
Debt instrument, face amount				$ 2,020,000,000
Securitized Utility Tariff Bonds \| AEK
Unusual or Infrequent Item, or Both [Line Items]
Debt instrument, face amount	$ 95,000,000

Variable Interest Entity - Narr

Variable Interest Entity - Narrative (Details) - USD ($)		9 Months Ended
Variable Interest Entity - Narrative (Details) - USD ($)	Jun. 20, 2023	Jun. 30, 2023	Jun. 30, 2022	Sep. 30, 2022	Mar. 31, 2021
Variable Interest Entity [Line Items]
Proceeds from issuance of securitized long-term debt by AEK		$ 95,000,000	$ 0
Long-term debt, fair value		5,760,036,000		$ 6,918,843,000
AEK \| Variable Interest Entity, Primary Beneficiary
Variable Interest Entity [Line Items]
Long-term debt		95,000,000
AEK \| Variable Interest Entity, Primary Beneficiary \| Securitized Utility Tariff Property
Variable Interest Entity [Line Items]
Proceeds from sale of intangible assets	$ 92,300,000
Intangible asset, useful life	10 years
Intangible assets, amortization period	5 years 3 months 21 days
Senior Notes
Variable Interest Entity [Line Items]
Debt instrument, face amount					$ 2,200,000,000
Series 2023-A Securitized Utility Tariff Bonds Due March 2033 \| Senior Notes \| AEK \| Variable Interest Entity, Primary Beneficiary
Variable Interest Entity [Line Items]
Debt instrument, face amount	$ 95,000,000
Debt instrument, interest rate	5.155%
Debt instrument, term	10 years
Proceeds from issuance of securitized long-term debt by AEK	$ 93,700,000
Long-term debt		95,000,000
Long-term debt, fair value		$ 94,200,000

Variable Interest Entity - Cond

Variable Interest Entity - Condensed Consolidated Balance Sheet (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Sep. 30, 2022
Variable Interest Entity [Line Items]
Restricted cash and cash equivalents	$ 1,876	$ 0
Securitized intangible asset, net	93,600	0
Current maturities of securitized long-term debt	5,973	0
Securitized long-term debt	89,027	$ 0
Variable Interest Entity, Primary Beneficiary \| AEK
Variable Interest Entity [Line Items]
Restricted cash and cash equivalents	1,876
Securitized intangible asset, net	93,600
Current maturities of securitized long-term debt	5,973
Securitized long-term debt	$ 89,027

Variable Interest Entity - Matu

Variable Interest Entity - Maturities of the Securitized Long-term Debt and Amortization Expense to the Securitized Intangible Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Sep. 30, 2022
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
Amortization Expense of Securitized Intangible Asset	$ 93,600	$ 0
Variable Interest Entity, Primary Beneficiary \| AEK
Maturities of Long-Term Debt [Abstract]
2023	0
2024	9,922
2025	8,207
2026	8,635
2027	9,086
Thereafter	59,150
Maturities of Securitized Long-Term Debt	95,000
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
2023	2,368
2024	8,073
2025	8,121
2026	8,545
2027	8,991
Thereafter	57,502
Amortization Expense of Securitized Intangible Asset	$ 93,600

Interim Pension and Other Pos_3

Interim Pension and Other Postretirement Benefit Plan Information - Narrative (Details) - USD ($) $ in Thousands			3 Months Ended			9 Months Ended
	Apr. 30, 2023	Apr. 29, 2023	Sep. 30, 2023	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Defined Benefit Plan Disclosure [Line Items]
Discount rate	5.21%	5.71%
Contribution to postretirement medical plans						$ 9,900
Forecast
Defined Benefit Plan Disclosure [Line Items]
Increase (decrease) of costs from plan revaluation			$ 100
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Settlement charge				$ 1,030	$ 0	1,030	$ 0
Contributions				8,000
Other Benefits
Defined Benefit Plan Disclosure [Line Items]
Settlement charge				0	$ 0	0	$ 0
Other Benefits \| Minimum
Defined Benefit Plan Disclosure [Line Items]
Expected future contributions				12,000		12,000
Other Benefits \| Maximum
Defined Benefit Plan Disclosure [Line Items]
Expected future contributions				$ 15,000		$ 15,000

Interim Pension and Other Pos_4

Interim Pension and Other Postretirement Benefit Plan Information - Components of Net Periodic Pension Cost (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 2,915	$ 4,323	$ 8,731	$ 12,970
Interest cost	7,265	5,063	21,915	15,190
Expected return on assets	(7,278)	(7,383)	(21,835)	(22,149)
Amortization of prior service cost (credit)	(30)	(58)	(91)	(174)
Amortization of actuarial (gain) loss	178	1,951	506	5,853
Settlements	(1,030)	0	(1,030)	0
Net periodic pension cost	4,080	3,896	10,256	11,690
Other Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	1,546	2,559	4,637	7,676
Interest cost	3,478	2,683	10,433	8,050
Expected return on assets	(2,804)	(3,312)	(8,411)	(9,937)
Amortization of prior service cost (credit)	(3,285)	(3,308)	(9,856)	(9,925)
Amortization of actuarial (gain) loss	(1,863)	0	(5,589)	0
Settlements	0	0	0	0
Net periodic pension cost	$ (2,928)	$ (1,378)	$ (8,786)	$ (4,136)

Commitments and Contingencies (

Commitments and Contingencies (Details) - Supply Commitment	9 Months Ended
Commitments and Contingencies (Details) - Supply Commitment	Jun. 30, 2023 $ / Mcf MMcf
Long-term Purchase Commitment [Line Items]
Contract term	1 year
Purchase commitment volume	17,000
Weighted Average
Long-term Purchase Commitment [Line Items]
Fixed price contracts (USD per Mcf) \| $ / Mcf	2.78
Short-term Contract with Customer
Long-term Purchase Commitment [Line Items]
Contract term	1 year
Purchase commitment volume	70,900
Long-term Contract with Customer Within Two To Three Years
Long-term Purchase Commitment [Line Items]
Purchase commitment volume	91,700
Long-term Contract with Customer Within Two To Three Years \| Minimum
Long-term Purchase Commitment [Line Items]
Contract term	2 years
Long-term Contract with Customer Within Two To Three Years \| Maximum
Long-term Purchase Commitment [Line Items]
Contract term	3 years

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
Income Taxes (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Sep. 30, 2022
Income Tax Contingency [Line Items]
Effective income tax rate	10.60%	9.30%	11%	8.50%
Regulatory liabilities	$ 1,251,092		$ 1,251,092		$ 1,358,907
Regulatory excess deferred taxes
Income Tax Contingency [Line Items]
Deferred tax liabilities, net	378,200		378,200
Regulatory liabilities	425,440		425,440		545,021
Regulatory excess deferred taxes \| Other Current Liabilities
Income Tax Contingency [Line Items]
Deferred tax liabilities, net	147,900		147,900		$ 159,800
Regulatory excess deferred taxes, to be returned, tranche one
Income Tax Contingency [Line Items]
Deferred tax liabilities, net	320,700		$ 320,700
Regulatory excess deferred taxes, to be returned, tranche one \| Minimum
Income Tax Contingency [Line Items]
Return basis, term			35 months
Regulatory excess deferred taxes, to be returned, tranche one \| Maximum
Income Tax Contingency [Line Items]
Return basis, term			60 months
Regulatory excess deferred taxes, to be returned, tranche two
Income Tax Contingency [Line Items]
Regulatory liabilities	54,500		$ 54,500
Regulatory excess deferred taxes, to be returned, tranche two \| Minimum
Income Tax Contingency [Line Items]
Return basis, term			15 years
Regulatory excess deferred taxes, to be returned, tranche two \| Maximum
Income Tax Contingency [Line Items]
Return basis, term			69 years
Regulatory excess deferred taxes, to be returned, tranche three
Income Tax Contingency [Line Items]
Deferred tax liabilities, net	$ 3,000		$ 3,000

Financial Instruments - Narrati

Financial Instruments - Narrative (Details)	3 Months Ended		9 Months Ended
Financial Instruments - Narrative (Details)	Jun. 30, 2023 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2023 USD ($) MMcf	Jun. 30, 2022 USD ($)	Apr. 30, 2023 USD ($)	Mar. 31, 2023 USD ($)	Sep. 30, 2022 USD ($)	Mar. 31, 2021 USD ($)
Derivative [Line Items]
Energy measure \| MMcf			19,735
Contract netting	$ 0		$ 0				$ 0
Cash collateral	0		0				$ 0
Net (gain) loss on settled interest rate agreements	(700,000)	$ 1,000,000	(2,100,000)	$ 2,900,000
Net realized gains in AOCI	$ 92,600,000		$ 92,600,000
Senior Notes
Derivative [Line Items]
Debt instrument, face amount								$ 2,200,000,000
Forward Interest Rate Swap \| Senior Notes
Derivative [Line Items]
Debt instrument, face amount					$ 250,000,000	$ 250,000,000
Gas Purchases \| Not Designated As Hedges: \| Commodity contracts
Derivative [Line Items]
Hedging percent	32%		32%
Energy measure \| MMcf			17,700
Minimum \| Gas Purchases \| Not Designated As Hedges: \| Commodity contracts
Derivative [Line Items]
Hedging percent	25%		25%
Maximum \| Gas Purchases \| Not Designated As Hedges: \| Commodity contracts
Derivative [Line Items]
Hedging percent	50%		50%

Financial Instruments - Schedul

Financial Instruments - Schedule of Interest Rate Risk Management Activities (Details) - Cash Flow Hedging - Designated As Hedge $ in Thousands	Jun. 30, 2023 USD ($)
Forward Interest Rate Swap
Derivative [Line Items]
Derivative notional amount	$ 1,600,000
Forward Interest Rate Swap, Planned Issued Fiscal 2024
Derivative [Line Items]
Derivative notional amount	700,000
Forward Interest Rate Swap, Planned Issued Fiscal 2025
Derivative [Line Items]
Derivative notional amount	600,000
Forward Interest Rate Swap, Planned Issued Fiscal 2026
Derivative [Line Items]
Derivative notional amount	$ 300,000

Financial Instruments - Sched_2

Financial Instruments - Schedule of Derivative Instruments in Statement of Financial Position, Fair Value (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Sep. 30, 2022
Derivatives Fair Value [Line Items]
Net financial instruments, assets	$ 405,976	$ 381,991
Net financial instruments, liabilities	(10,255)	(4,129)
Designated As Hedges:
Derivatives Fair Value [Line Items]
Gross financial instruments, assets	402,487	355,075
Gross financial instruments, liabilities	0	0
Designated As Hedges: \| Other current assets \| Interest rate contracts
Derivatives Fair Value [Line Items]
Gross financial instruments, assets	123,716
Designated As Hedges: \| Other current liabilities \| Interest rate contracts
Derivatives Fair Value [Line Items]
Gross financial instruments, liabilities	0
Designated As Hedges: \| Deferred charges and other assets \| Interest rate contracts
Derivatives Fair Value [Line Items]
Gross financial instruments, assets	278,771	355,075
Designated As Hedges: \| Deferred credits and other liabilities \| Interest rate contracts
Derivatives Fair Value [Line Items]
Gross financial instruments, liabilities	0	0
Not Designated As Hedges:
Derivatives Fair Value [Line Items]
Gross financial instruments, assets	3,489	26,916
Gross financial instruments, liabilities	(10,255)	(4,129)
Not Designated As Hedges: \| Other current assets \| Commodity contracts
Derivatives Fair Value [Line Items]
Gross financial instruments, assets	2,811	26,207
Not Designated As Hedges: \| Other current liabilities \| Commodity contracts
Derivatives Fair Value [Line Items]
Gross financial instruments, liabilities	(9,752)	(3,000)
Not Designated As Hedges: \| Deferred charges and other assets \| Commodity contracts
Derivatives Fair Value [Line Items]
Gross financial instruments, assets	678	709
Not Designated As Hedges: \| Deferred credits and other liabilities \| Commodity contracts
Derivatives Fair Value [Line Items]
Gross financial instruments, liabilities	$ (503)	$ (1,129)

Financial Instruments - Sched_3

Financial Instruments - Schedule of Cash Flow Hedges Included in Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Increase in fair value:
Interest rate agreements	$ 44,057	$ 158,993	$ 36,781	$ 233,511
Recognition of (gains) losses in earnings due to settlements:
Interest rate agreements	(530)	744	(1,590)	2,232
Total other comprehensive income from hedging, net of tax	$ 43,527	$ 159,737	$ 35,191	$ 235,743

Financial Instruments - Sched_4

Financial Instruments - Schedule Of Expected Deferred Gains (Losses) Recognition (Details) $ in Thousands	9 Months Ended
	Jun. 30, 2023 USD ($)
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Next twelve months	$ 2,120
Thereafter	90,437
Total	$ 92,557

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Sep. 30, 2022
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Financial instruments net assets	$ 405,976	$ 381,991
Debt and equity securities	104,379	96,012
Total assets	510,355	478,003
Financial instruments net liability	10,255	4,129
Registered investment companies
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Equity securities	27,569	26,367
Bond mutual funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Equity securities	37,267	32,367
Bonds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Debt securities	34,058	33,433
Money market funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Equity securities	5,485	3,845
Quoted Prices in Active Markets (Level 1)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Financial instruments gross assets	0	0
Debt and equity securities	64,836	58,734
Total assets	64,836	58,734
Financial instruments gross liability	0	0
Quoted Prices in Active Markets (Level 1) \| Registered investment companies
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Equity securities	27,569	26,367
Quoted Prices in Active Markets (Level 1) \| Bond mutual funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Equity securities	37,267	32,367
Quoted Prices in Active Markets (Level 1) \| Bonds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Debt securities	0	0
Quoted Prices in Active Markets (Level 1) \| Money market funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Equity securities	0	0
Significant Other Observable Inputs (Level 2)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Financial instruments gross assets	405,976	381,991
Debt and equity securities	39,543	37,278
Total assets	445,519	419,269
Financial instruments gross liability	10,255	4,129
Significant Other Observable Inputs (Level 2) \| Registered investment companies
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Equity securities	0	0
Significant Other Observable Inputs (Level 2) \| Bond mutual funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Equity securities	0	0
Significant Other Observable Inputs (Level 2) \| Bonds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Debt securities	34,058	33,433
Significant Other Observable Inputs (Level 2) \| Money market funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Equity securities	5,485	3,845
Significant Other Unobservable Inputs (Level 3)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Financial instruments gross assets	0	0
Debt and equity securities	0	0
Total assets	0	0
Financial instruments gross liability	0	0
Significant Other Unobservable Inputs (Level 3) \| Registered investment companies
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Equity securities	0	0
Significant Other Unobservable Inputs (Level 3) \| Bond mutual funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Equity securities	0	0
Significant Other Unobservable Inputs (Level 3) \| Bonds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Debt securities	0	0
Significant Other Unobservable Inputs (Level 3) \| Money market funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Equity securities	$ 0	$ 0

Fair Value Measurements - Narra

Fair Value Measurements - Narrative (Details) - USD ($)	Jun. 30, 2023	Sep. 30, 2022
Fair Value Disclosures [Abstract]
Allowance for credit losses	$ 0
Cost basis	$ 34,600,000	$ 34,100,000

Fair Value Measurements - Sch_2

Fair Value Measurements - Schedule of Debt Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Sep. 30, 2022
Fair Value Disclosures [Abstract]
Carrying Amount	$ 6,560,000	$ 7,960,000
Fair Value	$ 5,760,036	$ 6,918,843