Atmos Energy (ATO) 10-Q 2 Feb 21 2021 Q1 Quarterly report Financial data

Cover Page

Cover Page - shares	3 Months Ended
	Dec. 31, 2020	Jan. 29, 2021
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Dec. 31, 2020
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)		128,160,695
Entity Central Index Key	0000731802
Current Fiscal Year End Date	--09-30
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Amendment Flag	false

Concentration of Credit Risk

Concentration of Credit Risk	3 Months Ended
	Dec. 31, 2020
Risks and Uncertainties [Abstract]
Concentration of Credit Risk	Concentration of Credit RiskInformation regarding our concentration of credit risk is disclosed in Note 16 to the consolidated financial statements in our Annual Report on Form 10-K for the fiscal year ended September 30, 2020. During the three months ended December 31, 2020, there were no material changes in our concentration of credit risk.

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2020	Sep. 30, 2020
ASSETS
Property, plant and equipment	$ 16,412,507	$ 15,957,221
Less accumulated depreciation and amortization	2,650,364	2,601,874
Net property, plant and equipment	13,762,143	13,355,347
Current assets
Cash and cash equivalents	457,599	20,808
Accounts receivable, net	492,526	230,595
Gas stored underground	99,569	111,950
Other current assets	142,594	107,905
Total current assets	1,192,288	471,258
Goodwill	731,257	731,257
Deferred charges and other assets	790,191	801,170
Total assets	16,475,879	15,359,032
Shareholders’ equity
Common stock, no par value (stated at $0.005 per share); 200,000,000 shares authorized; issued and outstanding: 2020 — 125,882,477 shares; 2020 — 125,882,477 shares	641	629
Additional paid-in capital	4,600,314	4,377,149
Accumulated other comprehensive income (loss)	2,532	(57,589)
Retained earnings	2,609,669	2,471,014
Shareholders’ equity	7,213,156	6,791,203
Long-term debt	5,124,862	4,531,779
Total capitalization	12,338,018	11,322,982
Current liabilities
Accounts payable and accrued liabilities	284,995	235,775
Other current liabilities	512,673	546,461
Current maturities of long-term debt	171	165
Total current liabilities	797,839	782,401
Deferred income taxes	1,542,394	1,456,569
Regulatory excess deferred taxes	695,191	697,764
Regulatory cost of removal obligation	456,264	457,188
Deferred credits and other liabilities	646,173	642,128
Total shareholders' equity and liabilities	$ 16,475,879	$ 15,359,032

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Dec. 31, 2020	Sep. 30, 2020
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)	128,152,961	125,882,477
Common stock outstanding (in shares)	128,152,961	125,882,477

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Operating revenues	$ 914,480	$ 875,563
Purchased gas cost	288,260	296,868
Operation and maintenance expense	138,643	152,245
Depreciation and amortization expense	115,285	105,062
Taxes, other than income	73,452	68,607
Operating income	298,840	252,781
Other non-operating income	6,072	4,887
Interest charges	22,010	27,229
Income before income taxes	282,902	230,439
Income tax expense	65,224	51,766
Net income	$ 217,678	$ 178,673
Basic net income per share (USD per share)	$ 1.71	$ 1.47
Diluted net income per share (USD per share)	1.71	1.47
Cash dividends per share (USD per share)	$ 0.625	$ 0.575
Basic weighted average shares outstanding (in shares)	127,034	121,113
Diluted weighted average shares outstanding (in shares)	127,034	121,359
Other comprehensive income (loss), net of tax
Net unrealized holding gains on available-for-sale securities, net of tax	$ (63)	$ (1)
Cash flow hedges:
Amortization and unrealized gain (loss) on interest rate agreements, net of tax	60,184	1,053
Total other comprehensive income (loss)	60,121	1,052
Total comprehensive income	277,799	179,725
Distribution segment
Operating revenues	875,887	827,840
Pipeline and storage segment
Operating revenues	38,593	47,723
Operating Segments | Distribution segment
Operating revenues	876,650	828,504
Purchased gas cost	411,072	397,558
Operation and maintenance expense	108,802	114,352
Depreciation and amortization expense	82,870	76,074
Taxes, other than income	64,352	60,243
Operating income	209,554	180,277
Other non-operating income	835	1,954
Interest charges	10,712	16,362
Income before income taxes	199,677	165,869
Income tax expense	45,985	36,112
Net income	153,692	129,757
Operating Segments | Pipeline and storage segment
Operating revenues	159,713	148,176
Purchased gas cost	(1,244)	99
Operation and maintenance expense	30,156	38,221
Depreciation and amortization expense	32,415	28,988
Taxes, other than income	9,100	8,364
Operating income	89,286	72,504
Other non-operating income	5,237	2,933
Interest charges	11,298	10,867
Income before income taxes	83,225	64,570
Income tax expense	19,239	15,654
Net income	63,986	48,916
Eliminations
Operating revenues	(121,883)	(101,117)
Purchased gas cost	(121,568)	(100,789)
Operation and maintenance expense	(315)	(328)
Depreciation and amortization expense	0	0
Taxes, other than income	0	0
Operating income	0	0
Other non-operating income	0	0
Interest charges	0	0
Income before income taxes	0	0
Income tax expense	0	0
Net income	0	0
Eliminations | Distribution segment
Operating revenues	763	664
Eliminations | Pipeline and storage segment
Operating revenues	121,120	100,453
Purchased gas cost
Purchased gas cost	288,260	296,868
Purchased gas cost | Operating Segments | Distribution segment
Purchased gas cost	411,072	397,558
Purchased gas cost | Operating Segments | Pipeline and storage segment
Purchased gas cost	(1,244)	99
Purchased gas cost | Eliminations
Purchased gas cost	$ (121,568)	$ (100,789)

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Statement [Abstract]
Net unrealized holding losses on available-for-sale securities, tax	$ (18)	$ 0
Amortization and unrealized gain (loss) on interest rate agreements, tax	$ 17,395	$ 311

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Cash Flows From Operating Activities
Net income	$ 217,678	$ 178,673
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization expense	115,285	105,062
Deferred income taxes	64,587	46,726
Other	(2,976)	(616)
Net assets / liabilities from risk management activities	(816)	4,143
Net change in operating assets and liabilities	(236,689)	(161,543)
Net cash provided by operating activities	157,069	172,445
Cash Flows From Investing Activities
Capital expenditures	(456,809)	(529,186)
Debt and equity securities activities, net	511	(1,602)
Other, net	2,706	2,553
Net cash used in investing activities	(453,592)	(528,235)
Cash Flows From Financing Activities
Net decrease in short-term debt	0	(464,915)
Net proceeds from equity offering	216,002	259,005
Issuance of common stock through stock purchase and employee retirement plans	4,007	4,267
Proceeds from issuance of long-term debt	597,390	799,450
Cash dividends paid	(79,023)	(69,557)
Debt issuance costs	(5,062)	(7,738)
Net cash provided by financing activities	733,314	520,512
Net increase in cash and cash equivalents	436,791	164,722
Cash and cash equivalents at beginning of period	20,808	24,550
Cash and cash equivalents at end of period	$ 457,599	$ 189,272

Nature of Business

Nature of Business	3 Months Ended
	Dec. 31, 2020
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 three million residential, commercial, public authority and industrial customers through our six regulated distribution divisions, which at December 31, 2020, 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	3 Months Ended
	Dec. 31, 2020
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, aside from accounting policy changes noted below, 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, 2020. 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, 2020. Because of seasonal and other factors, the results of operations for the three-month period ended December 31, 2020 are not indicative of our results of operations for the full 2021 fiscal year, which ends September 30, 2021. No events have occurred subsequent to the balance sheet date that would require recognition or disclosure in the unaudited condensed consolidated financial statements. Significant accounting policies Except as noted below, related to the change in policies as a result of our adoption of new accounting standards, 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, 2020. Accounting pronouncements adopted in fiscal 2021 Effective October 1, 2020, we adopted new accounting guidance that requires credit losses on most financial assets measured at amortized cost and certain other instruments to be measured using an expected credit loss model. Under this model, we estimate credit losses over the entire contractual term of the instrument from the date of initial recognition of that instrument. The new guidance also introduces a new impairment recognition model for available-for-sale debt securities that will require credit losses to be recorded through an allowance account. We adopted the new guidance using a modified retrospective method. The adoption of this standard did not have a material impact on our financial position, results of operations and cash flows and no adjustments were made to October 1, 2020 opening balances as a result of this adoption. As required under the modified retrospective method of adoption, results for the reporting period beginning after October 1, 2020 are presented under Accounting Standards Codification (ASC) 326, while prior period amounts are not adjusted. See Notes 5 and 11 to the unaudited condensed consolidated financial statements for further discussion of implementation of the standard. Accounting pronouncements that will be effective after fiscal 2021 In March 2020, the Financial Accounting Standards Board (FASB) issued optional guidance which will ease the potential burden in accounting for or recognizing the effects of reference rate reform on financial reporting. The amendments provide optional expedients and exceptions for applying U.S. GAAP to contracts, hedging relationships and other transactions affected by the cessation of the London Interbank Offered Rate (LIBOR). The amendments can be elected immediately, as of March 12, 2020, through December 31, 2022. We are currently evaluating if we will apply the optional guidance as we assess the impact of the cessation of LIBOR on our current contracts and hedging relationships and the potential impact on our financial position, results of operations and cash flows. 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 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 and our regulatory excess deferred taxes and regulatory cost of removal obligation are reported separately. Significant regulatory assets and liabilities as of December 31, 2020 and September 30, 2020 included the following: December 31, September 30, (In thousands) Regulatory assets: Pension and postretirement benefit costs $ 146,734 $ 149,089 Infrastructure mechanisms (1) 155,526 183,943 Deferred gas costs 11,322 40,593 Recoverable loss on reacquired debt 4,529 4,894 Deferred pipeline record collection costs 30,166 29,839 Other 4,969 6,283 $ 353,246 $ 414,641 Regulatory liabilities: Regulatory excess deferred taxes (2) $ 713,993 $ 718,651 Regulatory cost of removal obligation 527,087 531,096 Deferred gas costs 15,196 19,985 Asset retirement obligation 20,348 20,348 APT annual adjustment mechanism 55,313 57,379 Other 19,433 19,554 $ 1,351,370 $ 1,367,013 (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 amount from the remeasurement of the net deferred tax liability included in our rate base as a result of the Tax Cuts and Jobs Act of 2017 (the "TCJA") and a Kansas legislative change enacted in fiscal 2020. Of this amount, $18.8 million as of December 31, 2020 and $20.9 million as of September 30, 2020 is recorded in other current liabilities. These liabilities are currently being returned to customers in most of our jurisdictions on a provisional basis over 15 to 69 years until formal orders establish the final refund periods. As of December 31, 2020, we received regulatory orders in most states to defer into a regulatory asset all expenses, beyond the normal course of business, related to Coronavirus Disease 2019 (COVID-19 or virus), including bad debt expense. As of December 31, 2020, no amounts have been recorded as regulatory assets or liabilities for expenses related to COVID-19.

Segment Information

Segment Information	3 Months Ended
	Dec. 31, 2020
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, 2020. Income statements and capital expenditures for the three months ended December 31, 2020 and 2019 by segment are presented in the following tables: Three Months Ended December 31, 2020 Distribution Pipeline and Storage Eliminations Consolidated (In thousands) Operating revenues from external parties $ 875,887 $ 38,593 $ — $ 914,480 Intersegment revenues 763 121,120 (121,883) — Total operating revenues 876,650 159,713 (121,883) 914,480 Purchased gas cost 411,072 (1,244) (121,568) 288,260 Operation and maintenance expense 108,802 30,156 (315) 138,643 Depreciation and amortization expense 82,870 32,415 — 115,285 Taxes, other than income 64,352 9,100 — 73,452 Operating income 209,554 89,286 — 298,840 Other non-operating income 835 5,237 — 6,072 Interest charges 10,712 11,298 — 22,010 Income before income taxes 199,677 83,225 — 282,902 Income tax expense 45,985 19,239 — 65,224 Net income $ 153,692 $ 63,986 $ — $ 217,678 Capital expenditures $ 306,016 $ 150,793 $ — $ 456,809 Three Months Ended December 31, 2019 Distribution Pipeline and Storage Eliminations Consolidated (In thousands) Operating revenues from external parties $ 827,840 $ 47,723 $ — $ 875,563 Intersegment revenues 664 100,453 (101,117) — Total operating revenues 828,504 148,176 (101,117) 875,563 Purchased gas cost 397,558 99 (100,789) 296,868 Operation and maintenance expense 114,352 38,221 (328) 152,245 Depreciation and amortization expense 76,074 28,988 — 105,062 Taxes, other than income 60,243 8,364 — 68,607 Operating income 180,277 72,504 — 252,781 Other non-operating income 1,954 2,933 — 4,887 Interest charges 16,362 10,867 — 27,229 Income before income taxes 165,869 64,570 — 230,439 Income tax expense 36,112 15,654 — 51,766 Net income $ 129,757 $ 48,916 $ — $ 178,673 Capital expenditures $ 404,247 $ 124,939 $ — $ 529,186 Balance sheet information at December 31, 2020 and September 30, 2020 by segment is presented in the following tables: December 31, 2020 Distribution Pipeline and Storage Eliminations Consolidated (In thousands) Property, plant and equipment, net $ 10,235,658 $ 3,526,485 $ — $ 13,762,143 Total assets $ 15,694,179 $ 3,757,875 $ (2,976,175) $ 16,475,879 September 30, 2020 Distribution Pipeline and Storage Eliminations Consolidated (In thousands) Property, plant and equipment, net $ 9,944,978 $ 3,410,369 $ — $ 13,355,347 Total assets $ 14,578,176 $ 3,647,907 $ (2,867,051) $ 15,359,032

Earnings Per Share

Earnings Per Share	3 Months Ended
	Dec. 31, 2020
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 unaudited condensed consolidated financial statements, when the impact is dilutive. Basic and diluted earnings per share for the three months ended December 31, 2020 and 2019 are calculated as follows: Three Months Ended December 31 2020 2019 (In thousands, except per share amounts) Basic Earnings Per Share Net income $ 217,678 $ 178,673 Less: Income allocated to participating securities 151 136 Income available to common shareholders $ 217,527 $ 178,537 Basic weighted average shares outstanding 127,034 121,113 Net income per share — Basic $ 1.71 $ 1.47 Diluted Earnings Per Share Income available to common shareholders $ 217,527 $ 178,537 Effect of dilutive shares — — Income available to common shareholders $ 217,527 $ 178,537 Basic weighted average shares outstanding 127,034 121,113 Dilutive shares — 246 Diluted weighted average shares outstanding 127,034 121,359 Net income per share - Diluted $ 1.71 $ 1.47

Revenue and Accounts Receivable

Revenue and Accounts Receivable	3 Months Ended
	Dec. 31, 2020
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, 2020. 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 months ended December 31, 2020 and 2019. Three Months Ended December 31, 2020 Three Months Ended December 31, 2019 Distribution Pipeline and Storage Distribution Pipeline and Storage (In thousands) Gas sales revenues: Residential $ 591,834 $ — $ 552,076 $ — Commercial 208,947 — 211,314 — Industrial 24,708 — 24,925 — Public authority and other 13,062 — 13,022 — Total gas sales revenues 838,551 — 801,337 — Transportation revenues 27,767 164,761 26,640 152,010 Miscellaneous revenues 2,396 5,148 6,786 5,155 Revenues from contracts with customers 868,714 169,909 834,763 157,165 Alternative revenue program revenues (1) 7,441 (10,196) (6,751) (8,989) Other revenues 495 — 492 — Total operating revenues $ 876,650 $ 159,713 $ 828,504 $ 148,176 (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 we share 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. The receivable balances are short term and generally do not extend beyond one month. To minimize credit risk, we assess the credit worthiness of new customers, require deposits where necessary, assess late fees, pursue collection activities and disconnect service for nonpayment. After disconnection, accounts are written off when deemed uncollectible. As described in Note 2, on October 1, 2020, we adopted new accounting guidance which requires credit losses on our accounts receivable to be measured using an expected credit loss model over the entire contractual term from the date of initial recognition. At each reporting period, we assess the allowance for uncollectible accounts based on historical experience, current conditions and consideration of expected future conditions. Circumstances which could affect our estimates include, but are not limited to, customer credit issues, the level of natural gas prices, customer deposits and general economic conditions. Due to the COVID-19 pandemic, in March 2020 we temporarily suspended disconnecting customers for nonpayment and stopped charging late fees. We are actively working with our customers experiencing financial hardship through flexible payment options and directing them to aid agencies for financial assistance. Our allowance for uncollectible accounts reflects the expected impact on our customers’ ability to pay when we resume disconnection activity. A rollforward of our allowance for uncollectible accounts for the three months ended December 31, 2020 is presented in the table below. The allowance excludes the gas cost portion of customers’ bills for approximately 78 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 December 31, 2020 Beginning balance, September 30, 2020 $ 29,949 Current period provisions 6,937 Write-offs charged against allowance (2,288) Recoveries of amounts previously written off 491 Ending balance, December 31, 2020 $ 35,089

Debt

Debt	3 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Debt	Debt The 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, 2020. Other than as described below, there were no material changes in the terms of our debt instruments during the three months ended December 31, 2020. Long-term debt at December 31, 2020 and September 30, 2020 consisted of the following: December 31, 2020 September 30, 2020 (In thousands) Unsecured 3.00% Senior Notes, due 2027 $ 500,000 $ 500,000 Unsecured 2.625% Senior Notes, due 2029 300,000 300,000 Unsecured 1.50% Senior Notes, due 2031 600,000 — Unsecured 5.95% Senior Notes, due 2034 200,000 200,000 Unsecured 5.50% Senior Notes, due 2041 400,000 400,000 Unsecured 4.15% Senior Notes, due 2043 500,000 500,000 Unsecured 4.125% Senior Notes, due 2044 750,000 750,000 Unsecured 4.30% Senior Notes, due 2048 600,000 600,000 Unsecured 4.125% Senior Notes, due 2049 450,000 450,000 Unsecured 3.375% Senior Notes, due 2049 500,000 500,000 Floating-rate term loan, due 2022 200,000 200,000 Medium-term note Series A, 1995-1, 6.67%, due 2025 10,000 10,000 Unsecured 6.75% Debentures, due 2028 150,000 150,000 Finance lease obligations 8,608 8,631 Total long-term debt 5,168,608 4,568,631 Less: Original issue discount on unsecured senior notes and debentures 3,090 583 Debt issuance cost 40,485 36,104 Current maturities 171 165 $ 5,124,862 $ 4,531,779 On October 1, 2020, we completed a public offering of $600 million of 1.50% senior notes due 2031. The net proceeds from the offering, after the underwriting discount and offering expenses, of $592.3 million, were used for general corporate purposes, including the repayment of working capital borrowings pursuant to our commercial paper program and the related settlement of our interest rate swaps. The effective interest rate on these notes is 1.71%, after giving effect to the offering costs and settlement of our interest rate swaps. 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 with an equity-to-total-capitalization ratio between 50% and 60%, inclusive of long-term and short-term debt. Our short-term borrowing requirements are driven primarily by construction work in progress and the seasonal nature of the natural gas business. Changes in the price of natural gas and the amount of natural gas we need to supply our customers’ needs could significantly affect our borrowing requirements. 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 approximately $2.2 billion of total working capital funding. The primary source of our funding is our commercial paper program, which is supported by a five-year unsecured $1.5 billion credit facility that expires on September 25, 2023. The facility bears interest at a base rate or at a LIBOR-based rate for the applicable interest period, plus a margin ranging from zero percent to 1.25 percent, 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 December 31, 2020 and September 30, 2020, there were no amounts outstanding under our commercial paper program. We have a $600 million 364-day unsecured revolving credit facility, which expires April 22, 2021 and is used to provide additional working capital funding. The facility bears interest at a base rate or at a LIBOR-based rate for the applicable interest period, plus a margin ranging from zero percent to 1.25 percent, based on the Company's credit ratings. At December 31, 2020, there were no borrowings outstanding under this facility. Additionally, we have a $50 million 364-day unsecured facility, which expires on March 31, 2021 and is used to provide working capital funding. There were no borrowings outstanding under this facility as of December 31, 2020. Finally, we have a $50 million 364-day unsecured revolving credit facility, which expires April 29, 2021 and is used to issue letters of credit and to provide working capital funding. At December 31, 2020, there were no borrowings outstanding under this facility; however, outstanding letters of credit reduced the total amount available to us to $44.4 million. 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 December 31, 2020, our total-debt-to-total-capitalization ratio, as defined in the agreements, was 43 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 December 31, 2020. 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	3 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Shareholders' Equity	Shareholders' Equity The following tables present a reconciliation of changes in stockholders' equity for the three months ended December 31, 2020 and 2019. Common stock Additional Accumulated Retained Total Number of Stated (In thousands, except share and per share data) Balance, September 30, 2020 125,882,477 $ 629 $ 4,377,149 $ (57,589) $ 2,471,014 $ 6,791,203 Net income — — — — 217,678 217,678 Other comprehensive income — — — 60,121 — 60,121 Cash dividends ($0.625 per share) — — — — (79,023) (79,023) Common stock issued: Public and other stock offerings 2,126,118 11 219,998 — — 220,009 Stock-based compensation plans 144,366 1 3,167 — — 3,168 Balance, December 31, 2020 128,152,961 $ 641 $ 4,600,314 $ 2,532 $ 2,609,669 $ 7,213,156 Common stock Additional Accumulated Retained Total Number of Stated (In thousands, except share and per share data) Balance, September 30, 2019 119,338,925 $ 597 $ 3,712,194 $ (114,583) $ 2,152,015 $ 5,750,223 Net income — — — — 178,673 178,673 Other comprehensive income — — — 1,052 — 1,052 Cash dividends ($0.575 per share) — — — — (69,557) (69,557) Common stock issued: Public and other stock offerings 2,758,929 13 263,259 — — 263,272 Stock-based compensation plans 164,549 1 4,111 — — 4,112 Balance, December 31, 2019 122,262,403 $ 611 $ 3,979,564 $ (113,531) $ 2,261,131 $ 6,127,775 Shelf Registration, At-the-Market Equity Sales Program and Equity Issuances On February 11, 2020, we filed a shelf registration statement with the Securities and Exchange Commission (SEC) that allows us to issue up to $4.0 billion in common stock and/or debt securities, which expires February 11, 2023. At December 31, 2020, approximately $2.4 billion of securities remained available for issuance under the shelf registration statement. During the three months ended December 31, 2020, we executed forward sales under our ATM equity sales program with various forward sellers who borrowed and sold 1,201,674 shares of our common stock at an aggregate price of $121.8 million. During the three months ended December 31, 2020, we also settled forward sale agreements with respect to 2,085,492 shares that had been borrowed and sold by various forward sellers during fiscal 2019 under the ATM program for net proceeds of $216.0 million. As of December 31, 2020, approximately $430 million of equity remains available for issuance under the ATM program. Additionally, we had $246.8 million in available proceeds from outstanding forward sale agreements, as detailed below. Maturity Shares Available Net Proceeds Available Forward Price June 30, 2021 1,060,660 $ 107,255 $ 101.12 September 30, 2021 1,391,517 139,579 $ 100.31 Total 2,452,177 $ 246,834 $ 100.66 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 as they are amortized. 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, 2020 $ 238 $ (57,827) $ (57,589) Other comprehensive income (loss) before reclassifications (63) 59,042 58,979 Amounts reclassified from accumulated other comprehensive income — 1,142 1,142 Net current-period other comprehensive income (loss) (63) 60,184 60,121 December 31, 2020 $ 175 $ 2,357 $ 2,532 Available- Interest Rate Total (In thousands) September 30, 2019 $ 132 $ (114,715) $ (114,583) Other comprehensive loss before reclassifications (1) — (1) Amounts reclassified from accumulated other comprehensive income — 1,053 1,053 Net current-period other comprehensive income (loss) (1) 1,053 1,052 December 31, 2019 $ 131 $ (113,662) $ (113,531)

Interim Pension and Other Postr

Interim Pension and Other Postretirement Benefit Plan Information	3 Months Ended
	Dec. 31, 2020
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 months ended December 31, 2020 and 2019 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. Three Months Ended December 31 Pension Benefits Other Benefits 2020 2019 2020 2019 (In thousands) Components of net periodic pension cost: Service cost $ 4,612 $ 4,653 $ 4,306 $ 3,366 Interest cost (1) 5,028 5,843 2,660 2,653 Expected return on assets (1) (6,978) (7,079) (2,614) (2,625) Amortization of prior service cost (credit) (1) (58) (58) 43 43 Amortization of actuarial (gain) loss (1) 3,172 (1,271) — (334) Net periodic pension cost $ 5,776 $ 2,088 $ 4,395 $ 3,103 (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, 2020. For the three months ended December 31, 2020 we contributed $4.1 million to our postretirement medical plans. We anticipate contributing a total of between $15 million and $25 million to our postretirement plans during fiscal 2021.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Dec. 31, 2020
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 maintain liability insurance for various risks associated with the operation of our natural gas pipelines and facilities, including for property damage and bodily injury. These liability insurance policies generally require us to be responsible for the first $1.0 million (self-insured retention) of each incident. The National Transportation Safety Board (NTSB) held a public meeting on January 12, 2021 to determine the probable cause of the incident that occurred at a Dallas, Texas residence on February 23, 2018 that resulted in one fatality and injuries to four other residents. At the meeting, the Board deliberated and voted on proposed findings of fact, a probable cause statement, and safety recommendations. At the conclusion of the Board meeting, the NTSB issued an abstract to its website (www.ntsb.gov) that included an Executive Summary, Findings, Probable Cause, and Recommendations. The NTSB noted in the Abstract that the NTSB staff is currently making final revisions to the report and that the final report and safety recommendations letters would be later distributed to recommendation recipients, including Atmos Energy. 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 indexed to natural gas hubs. These purchase commitment contracts are detailed in our Annual Report on Form 10-K for the fiscal year ended September 30, 2020. There were no material changes to the purchase commitments for the three months ended December 31, 2020. Rate Regulatory Proceedings As of December 31, 2020, routine rate regulatory proceedings were in progress in Colorado, Kansas and West Texas, 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 three months ended December 31, 2020.

Financial Instruments

Financial Instruments	3 Months Ended
	Dec. 31, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Financial Instruments	Financial InstrumentsWe 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 14 to the consolidated financial statements in our Annual Report on Form 10-K for the fiscal year ended September 30, 2020. During the three months ended December 31, 2020, 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 2020-2021 heating season (generally October through March), in the jurisdictions where we are permitted to utilize financial instruments, we anticipate hedging approximately 39 percent, or 15.8 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. As of December 31, 2020, we had the following forward starting interest rate swaps to effectively fix the Treasury yield component which we designated as cash flow hedges at the time the agreements were executed: Planned Debt Issuance Date Amount Hedged Interest Rate Fiscal 2022 $ 450,000 1.33 % Fiscal 2023 300,000 1.36 % Fiscal 2025 300,000 1.35 % $ 1,050,000 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 December 31, 2020, 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 December 31, 2020, we had 11,641 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 December 31, 2020 and September 30, 2020. The gross amounts of recognized assets and liabilities are netted within our unaudited condensed consolidated balance sheets to the extent that we have netting arrangements with our counterparties. However, for December 31, 2020 and September 30, 2020, no gross amounts and no cash collateral were netted within our consolidated balance sheet. Balance Sheet Location Assets Liabilities (In thousands) December 31, 2020 Designated As Hedges: Interest rate contracts Other current assets / $ 56,484 $ — Interest rate contracts Deferred charges and other assets / 92,678 — Total 149,162 — Not Designated As Hedges: Commodity contracts Other current assets / 993 (1,843) Commodity contracts Deferred charges and other assets / 243 — Total 1,236 (1,843) Gross / Net Financial Instruments $ 150,398 $ (1,843) Balance Sheet Location Assets Liabilities (In thousands) September 30, 2020 Designated As Hedges: Interest rate contracts Deferred charges and other assets / $ 73,055 $ — Total 73,055 — Not Designated As Hedges: Commodity contracts Other current assets / 5,687 (2,015) Commodity contracts Deferred charges and other assets / 1,936 — Total 7,623 (2,015) Gross / Net Financial Instruments $ 80,678 $ (2,015) 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 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 December 31, 2020 and 2019 was $1.5 million and $1.4 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 months ended December 31, 2020 and 2019. The amounts included in the table below exclude gains and losses arising from ineffectiveness because those amounts are immediately recognized in the statement of comprehensive income as incurred. Three Months Ended December 31 2020 2019 (In thousands) Increase in fair value: Interest rate agreements $ 59,042 $ — Recognition of losses in earnings due to settlements: Interest rate agreements 1,142 1,053 Total other comprehensive income (loss) from hedging, net of tax $ 60,184 $ 1,053 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 December 31, 2020, we had $113.4 million of net realized losses 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 losses 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 2049. 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 $ (4,566) Thereafter (108,794) Total $ (113,360) 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	3 Months Ended
	Dec. 31, 2020
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, accounts receivable and accounts payable 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, 2020. During the three months ended December 31, 2020, 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 9 to the consolidated financial statements in our Annual Report on Form 10-K for the fiscal year ended September 30, 2020. 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 December 31, 2020 and September 30, 2020. 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 December 31, 2020 (In thousands) Assets: Financial instruments $ — $ 150,398 $ — $ — $ 150,398 Debt and equity securities Registered investment companies 35,518 — — — 35,518 Bond mutual funds 30,204 — — — 30,204 Bonds (2) — 34,142 — — 34,142 Money market funds — 6,162 — — 6,162 Total debt and equity securities 65,722 40,304 — — 106,026 Total assets $ 65,722 $ 190,702 $ — $ — $ 256,424 Liabilities: Financial instruments $ — $ 1,843 $ — $ — $ 1,843 Quoted Significant Other Observable Inputs (Level 2) (1) Significant Netting and September 30, 2020 (In thousands) Assets: Financial instruments $ — $ 80,678 $ — $ — $ 80,678 Debt and equity securities Registered investment companies 37,831 — — — 37,831 Bond mutual funds 29,166 — — — 29,166 Bonds (2) — 32,900 — — 32,900 Money market funds — 4,055 — — 4,055 Total debt and equity securities 66,997 36,955 — — 103,952 Total assets $ 66,997 $ 117,633 $ — $ — $ 184,630 Liabilities: Financial instruments $ — $ 2,015 $ — $ — $ 2,015 (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 further in Note 2 to the unaudited condensed consolidated financial statements, we adopted ASC 326 effective October 1, 2020. In accordance with the new guidance, 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 December 31, 2020, no allowance for credit losses was recorded for our available-for-sale debt securities. At December 31, 2020 and September 30, 2020, the amortized cost of our available-for-sale debt securities was $33.9 million and $32.6 million. At December 31, 2020, we maintained investments in bonds that have contractual maturity dates ranging from January 2021 through December 2023. 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 December 31, 2020 and September 30, 2020: December 31, 2020 September 30, 2020 (In thousands) Carrying Amount $ 5,160,000 $ 4,560,000 Fair Value $ 6,294,671 $ 5,597,183

Unaudited Financial Informati_2

Unaudited Financial Information (Policies)	3 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Accounting pronouncements adopted and not yet adopted	Accounting pronouncements adopted in fiscal 2021 Effective October 1, 2020, we adopted new accounting guidance that requires credit losses on most financial assets measured at amortized cost and certain other instruments to be measured using an expected credit loss model. Under this model, we estimate credit losses over the entire contractual term of the instrument from the date of initial recognition of that instrument. The new guidance also introduces a new impairment recognition model for available-for-sale debt securities that will require credit losses to be recorded through an allowance account. We adopted the new guidance using a modified retrospective method. The adoption of this standard did not have a material impact on our financial position, results of operations and cash flows and no adjustments were made to October 1, 2020 opening balances as a result of this adoption. As required under the modified retrospective method of adoption, results for the reporting period beginning after October 1, 2020 are presented under Accounting Standards Codification (ASC) 326, while prior period amounts are not adjusted. See Notes 5 and 11 to the unaudited condensed consolidated financial statements for further discussion of implementation of the standard. Accounting pronouncements that will be effective after fiscal 2021 In March 2020, the Financial Accounting Standards Board (FASB) issued optional guidance which will ease the potential burden in accounting for or recognizing the effects of reference rate reform on financial reporting. The amendments provide optional expedients and exceptions for applying U.S. GAAP to contracts, hedging relationships and other transactions affected by the cessation of the London Interbank Offered Rate (LIBOR). The amendments can be elected immediately, as of March 12, 2020, through December 31, 2022. We are currently evaluating if we will apply the optional guidance as we assess the impact of the cessation of LIBOR on our current contracts and hedging relationships and the potential impact on our financial position, results of operations and cash flows.
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 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 and our regulatory excess deferred taxes and regulatory cost of removal obligation are reported separately.
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 unaudited 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, accounts receivable and accounts payable 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, 2020. During the three months ended December 31, 2020, there were no changes in these methods.

Unaudited Financial Informati_3

Unaudited Financial Information (Table)	3 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Schedule of Regulatory Assets	Significant regulatory assets and liabilities as of December 31, 2020 and September 30, 2020 included the following: December 31, September 30, (In thousands) Regulatory assets: Pension and postretirement benefit costs $ 146,734 $ 149,089 Infrastructure mechanisms (1) 155,526 183,943 Deferred gas costs 11,322 40,593 Recoverable loss on reacquired debt 4,529 4,894 Deferred pipeline record collection costs 30,166 29,839 Other 4,969 6,283 $ 353,246 $ 414,641 Regulatory liabilities: Regulatory excess deferred taxes (2) $ 713,993 $ 718,651 Regulatory cost of removal obligation 527,087 531,096 Deferred gas costs 15,196 19,985 Asset retirement obligation 20,348 20,348 APT annual adjustment mechanism 55,313 57,379 Other 19,433 19,554 $ 1,351,370 $ 1,367,013 (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 amount from the remeasurement of the net deferred tax liability included in our rate base as a result of the Tax Cuts and Jobs Act of 2017 (the "TCJA") and a Kansas legislative change enacted in fiscal 2020. Of this amount, $18.8 million as of December 31, 2020 and $20.9 million as of September 30, 2020 is recorded in other current liabilities. These liabilities are currently being returned to customers in most of our jurisdictions on a provisional basis over 15 to 69 years until formal orders establish the final refund periods.
Schedule of Regulatory Liabilities	Significant regulatory assets and liabilities as of December 31, 2020 and September 30, 2020 included the following: December 31, September 30, (In thousands) Regulatory assets: Pension and postretirement benefit costs $ 146,734 $ 149,089 Infrastructure mechanisms (1) 155,526 183,943 Deferred gas costs 11,322 40,593 Recoverable loss on reacquired debt 4,529 4,894 Deferred pipeline record collection costs 30,166 29,839 Other 4,969 6,283 $ 353,246 $ 414,641 Regulatory liabilities: Regulatory excess deferred taxes (2) $ 713,993 $ 718,651 Regulatory cost of removal obligation 527,087 531,096 Deferred gas costs 15,196 19,985 Asset retirement obligation 20,348 20,348 APT annual adjustment mechanism 55,313 57,379 Other 19,433 19,554 $ 1,351,370 $ 1,367,013 (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 amount from the remeasurement of the net deferred tax liability included in our rate base as a result of the Tax Cuts and Jobs Act of 2017 (the "TCJA") and a Kansas legislative change enacted in fiscal 2020. Of this amount, $18.8 million as of December 31, 2020 and $20.9 million as of September 30, 2020 is recorded in other current liabilities. These liabilities are currently being returned to customers in most of our jurisdictions on a provisional basis over 15 to 69 years until formal orders establish the final refund periods.

Segment Information (Table)

Segment Information (Table)	3 Months Ended
	Dec. 31, 2020
Segment Reporting [Abstract]
Schedule of Segment Reporting Information, by Segment	Income statements and capital expenditures for the three months ended December 31, 2020 and 2019 by segment are presented in the following tables: Three Months Ended December 31, 2020 Distribution Pipeline and Storage Eliminations Consolidated (In thousands) Operating revenues from external parties $ 875,887 $ 38,593 $ — $ 914,480 Intersegment revenues 763 121,120 (121,883) — Total operating revenues 876,650 159,713 (121,883) 914,480 Purchased gas cost 411,072 (1,244) (121,568) 288,260 Operation and maintenance expense 108,802 30,156 (315) 138,643 Depreciation and amortization expense 82,870 32,415 — 115,285 Taxes, other than income 64,352 9,100 — 73,452 Operating income 209,554 89,286 — 298,840 Other non-operating income 835 5,237 — 6,072 Interest charges 10,712 11,298 — 22,010 Income before income taxes 199,677 83,225 — 282,902 Income tax expense 45,985 19,239 — 65,224 Net income $ 153,692 $ 63,986 $ — $ 217,678 Capital expenditures $ 306,016 $ 150,793 $ — $ 456,809 Three Months Ended December 31, 2019 Distribution Pipeline and Storage Eliminations Consolidated (In thousands) Operating revenues from external parties $ 827,840 $ 47,723 $ — $ 875,563 Intersegment revenues 664 100,453 (101,117) — Total operating revenues 828,504 148,176 (101,117) 875,563 Purchased gas cost 397,558 99 (100,789) 296,868 Operation and maintenance expense 114,352 38,221 (328) 152,245 Depreciation and amortization expense 76,074 28,988 — 105,062 Taxes, other than income 60,243 8,364 — 68,607 Operating income 180,277 72,504 — 252,781 Other non-operating income 1,954 2,933 — 4,887 Interest charges 16,362 10,867 — 27,229 Income before income taxes 165,869 64,570 — 230,439 Income tax expense 36,112 15,654 — 51,766 Net income $ 129,757 $ 48,916 $ — $ 178,673 Capital expenditures $ 404,247 $ 124,939 $ — $ 529,186 Balance sheet information at December 31, 2020 and September 30, 2020 by segment is presented in the following tables: December 31, 2020 Distribution Pipeline and Storage Eliminations Consolidated (In thousands) Property, plant and equipment, net $ 10,235,658 $ 3,526,485 $ — $ 13,762,143 Total assets $ 15,694,179 $ 3,757,875 $ (2,976,175) $ 16,475,879 September 30, 2020 Distribution Pipeline and Storage Eliminations Consolidated (In thousands) Property, plant and equipment, net $ 9,944,978 $ 3,410,369 $ — $ 13,355,347 Total assets $ 14,578,176 $ 3,647,907 $ (2,867,051) $ 15,359,032

Earnings Per Share (Table)

Earnings Per Share (Table)	3 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	Basic and diluted earnings per share for the three months ended December 31, 2020 and 2019 are calculated as follows: Three Months Ended December 31 2020 2019 (In thousands, except per share amounts) Basic Earnings Per Share Net income $ 217,678 $ 178,673 Less: Income allocated to participating securities 151 136 Income available to common shareholders $ 217,527 $ 178,537 Basic weighted average shares outstanding 127,034 121,113 Net income per share — Basic $ 1.71 $ 1.47 Diluted Earnings Per Share Income available to common shareholders $ 217,527 $ 178,537 Effect of dilutive shares — — Income available to common shareholders $ 217,527 $ 178,537 Basic weighted average shares outstanding 127,034 121,113 Dilutive shares — 246 Diluted weighted average shares outstanding 127,034 121,359 Net income per share - Diluted $ 1.71 $ 1.47

Revenue and Accounts Receivab_2

Revenue and Accounts Receivable (Table)	3 Months Ended
	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
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 months ended December 31, 2020 and 2019. Three Months Ended December 31, 2020 Three Months Ended December 31, 2019 Distribution Pipeline and Storage Distribution Pipeline and Storage (In thousands) Gas sales revenues: Residential $ 591,834 $ — $ 552,076 $ — Commercial 208,947 — 211,314 — Industrial 24,708 — 24,925 — Public authority and other 13,062 — 13,022 — Total gas sales revenues 838,551 — 801,337 — Transportation revenues 27,767 164,761 26,640 152,010 Miscellaneous revenues 2,396 5,148 6,786 5,155 Revenues from contracts with customers 868,714 169,909 834,763 157,165 Alternative revenue program revenues (1) 7,441 (10,196) (6,751) (8,989) Other revenues 495 — 492 — Total operating revenues $ 876,650 $ 159,713 $ 828,504 $ 148,176 (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 we share with its tariffed customers 75% of the difference between the total non-tariffed revenues earned during a test period and a revenue benchmark.
Allowance for Credit Loss Activity	A rollforward of our allowance for uncollectible accounts for the three months ended December 31, 2020 is presented in the table below. The allowance excludes the gas cost portion of customers’ bills for approximately 78 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 December 31, 2020 Beginning balance, September 30, 2020 $ 29,949 Current period provisions 6,937 Write-offs charged against allowance (2,288) Recoveries of amounts previously written off 491 Ending balance, December 31, 2020 $ 35,089

Debt (Table)

Debt (Table)	3 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Schedule of Long-term Debt Instruments	Long-term debt at December 31, 2020 and September 30, 2020 consisted of the following: December 31, 2020 September 30, 2020 (In thousands) Unsecured 3.00% Senior Notes, due 2027 $ 500,000 $ 500,000 Unsecured 2.625% Senior Notes, due 2029 300,000 300,000 Unsecured 1.50% Senior Notes, due 2031 600,000 — Unsecured 5.95% Senior Notes, due 2034 200,000 200,000 Unsecured 5.50% Senior Notes, due 2041 400,000 400,000 Unsecured 4.15% Senior Notes, due 2043 500,000 500,000 Unsecured 4.125% Senior Notes, due 2044 750,000 750,000 Unsecured 4.30% Senior Notes, due 2048 600,000 600,000 Unsecured 4.125% Senior Notes, due 2049 450,000 450,000 Unsecured 3.375% Senior Notes, due 2049 500,000 500,000 Floating-rate term loan, due 2022 200,000 200,000 Medium-term note Series A, 1995-1, 6.67%, due 2025 10,000 10,000 Unsecured 6.75% Debentures, due 2028 150,000 150,000 Finance lease obligations 8,608 8,631 Total long-term debt 5,168,608 4,568,631 Less: Original issue discount on unsecured senior notes and debentures 3,090 583 Debt issuance cost 40,485 36,104 Current maturities 171 165 $ 5,124,862 $ 4,531,779

Shareholders' Equity (Table)

Shareholders' Equity (Table)	3 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Reconciliation of Changes in Stockholders Equity	The following tables present a reconciliation of changes in stockholders' equity for the three months ended December 31, 2020 and 2019. Common stock Additional Accumulated Retained Total Number of Stated (In thousands, except share and per share data) Balance, September 30, 2020 125,882,477 $ 629 $ 4,377,149 $ (57,589) $ 2,471,014 $ 6,791,203 Net income — — — — 217,678 217,678 Other comprehensive income — — — 60,121 — 60,121 Cash dividends ($0.625 per share) — — — — (79,023) (79,023) Common stock issued: Public and other stock offerings 2,126,118 11 219,998 — — 220,009 Stock-based compensation plans 144,366 1 3,167 — — 3,168 Balance, December 31, 2020 128,152,961 $ 641 $ 4,600,314 $ 2,532 $ 2,609,669 $ 7,213,156 Common stock Additional Accumulated Retained Total Number of Stated (In thousands, except share and per share data) Balance, September 30, 2019 119,338,925 $ 597 $ 3,712,194 $ (114,583) $ 2,152,015 $ 5,750,223 Net income — — — — 178,673 178,673 Other comprehensive income — — — 1,052 — 1,052 Cash dividends ($0.575 per share) — — — — (69,557) (69,557) Common stock issued: Public and other stock offerings 2,758,929 13 263,259 — — 263,272 Stock-based compensation plans 164,549 1 4,111 — — 4,112 Balance, December 31, 2019 122,262,403 $ 611 $ 3,979,564 $ (113,531) $ 2,261,131 $ 6,127,775
Summary of Forward Sales Agreements	Additionally, we had $246.8 million in available proceeds from outstanding forward sale agreements, as detailed below. Maturity Shares Available Net Proceeds Available Forward Price June 30, 2021 1,060,660 $ 107,255 $ 101.12 September 30, 2021 1,391,517 139,579 $ 100.31 Total 2,452,177 $ 246,834 $ 100.66
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, 2020 $ 238 $ (57,827) $ (57,589) Other comprehensive income (loss) before reclassifications (63) 59,042 58,979 Amounts reclassified from accumulated other comprehensive income — 1,142 1,142 Net current-period other comprehensive income (loss) (63) 60,184 60,121 December 31, 2020 $ 175 $ 2,357 $ 2,532 Available- Interest Rate Total (In thousands) September 30, 2019 $ 132 $ (114,715) $ (114,583) Other comprehensive loss before reclassifications (1) — (1) Amounts reclassified from accumulated other comprehensive income — 1,053 1,053 Net current-period other comprehensive income (loss) (1) 1,053 1,052 December 31, 2019 $ 131 $ (113,662) $ (113,531)

Interim Pension and Other Pos_2

Interim Pension and Other Postretirement Benefit Plan Information (Table)	3 Months Ended
	Dec. 31, 2020
Retirement Benefits, Description [Abstract]
Schedule of Net Benefit Costs	The components of our net periodic pension cost for our pension and other postretirement benefit plans for the three months ended December 31, 2020 and 2019 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. Three Months Ended December 31 Pension Benefits Other Benefits 2020 2019 2020 2019 (In thousands) Components of net periodic pension cost: Service cost $ 4,612 $ 4,653 $ 4,306 $ 3,366 Interest cost (1) 5,028 5,843 2,660 2,653 Expected return on assets (1) (6,978) (7,079) (2,614) (2,625) Amortization of prior service cost (credit) (1) (58) (58) 43 43 Amortization of actuarial (gain) loss (1) 3,172 (1,271) — (334) Net periodic pension cost $ 5,776 $ 2,088 $ 4,395 $ 3,103 (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, 2020.

Financial Instruments (Table)

Financial Instruments (Table)	3 Months Ended
	Dec. 31, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivatives	As of December 31, 2020, we had the following forward starting interest rate swaps to effectively fix the Treasury yield component which we designated as cash flow hedges at the time the agreements were executed: Planned Debt Issuance Date Amount Hedged Interest Rate Fiscal 2022 $ 450,000 1.33 % Fiscal 2023 300,000 1.36 % Fiscal 2025 300,000 1.35 % $ 1,050,000
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 December 31, 2020 and September 30, 2020. The gross amounts of recognized assets and liabilities are netted within our unaudited condensed consolidated balance sheets to the extent that we have netting arrangements with our counterparties. However, for December 31, 2020 and September 30, 2020, no gross amounts and no cash collateral were netted within our consolidated balance sheet. Balance Sheet Location Assets Liabilities (In thousands) December 31, 2020 Designated As Hedges: Interest rate contracts Other current assets / $ 56,484 $ — Interest rate contracts Deferred charges and other assets / 92,678 — Total 149,162 — Not Designated As Hedges: Commodity contracts Other current assets / 993 (1,843) Commodity contracts Deferred charges and other assets / 243 — Total 1,236 (1,843) Gross / Net Financial Instruments $ 150,398 $ (1,843) Balance Sheet Location Assets Liabilities (In thousands) September 30, 2020 Designated As Hedges: Interest rate contracts Deferred charges and other assets / $ 73,055 $ — Total 73,055 — Not Designated As Hedges: Commodity contracts Other current assets / 5,687 (2,015) Commodity contracts Deferred charges and other assets / 1,936 — Total 7,623 (2,015) Gross / Net Financial Instruments $ 80,678 $ (2,015)
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 months ended December 31, 2020 and 2019. The amounts included in the table below exclude gains and losses arising from ineffectiveness because those amounts are immediately recognized in the statement of comprehensive income as incurred. Three Months Ended December 31 2020 2019 (In thousands) Increase in fair value: Interest rate agreements $ 59,042 $ — Recognition of losses in earnings due to settlements: Interest rate agreements 1,142 1,053 Total other comprehensive income (loss) from hedging, net of tax $ 60,184 $ 1,053
Schedule Of Expected Deferred Gains (Losses) Recognition	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 $ (4,566) Thereafter (108,794) Total $ (113,360)

Fair Value Measurements (Table)

Fair Value Measurements (Table)	3 Months Ended
	Dec. 31, 2020
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 December 31, 2020 and September 30, 2020. 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 December 31, 2020 (In thousands) Assets: Financial instruments $ — $ 150,398 $ — $ — $ 150,398 Debt and equity securities Registered investment companies 35,518 — — — 35,518 Bond mutual funds 30,204 — — — 30,204 Bonds (2) — 34,142 — — 34,142 Money market funds — 6,162 — — 6,162 Total debt and equity securities 65,722 40,304 — — 106,026 Total assets $ 65,722 $ 190,702 $ — $ — $ 256,424 Liabilities: Financial instruments $ — $ 1,843 $ — $ — $ 1,843 Quoted Significant Other Observable Inputs (Level 2) (1) Significant Netting and September 30, 2020 (In thousands) Assets: Financial instruments $ — $ 80,678 $ — $ — $ 80,678 Debt and equity securities Registered investment companies 37,831 — — — 37,831 Bond mutual funds 29,166 — — — 29,166 Bonds (2) — 32,900 — — 32,900 Money market funds — 4,055 — — 4,055 Total debt and equity securities 66,997 36,955 — — 103,952 Total assets $ 66,997 $ 117,633 $ — $ — $ 184,630 Liabilities: Financial instruments $ — $ 2,015 $ — $ — $ 2,015 (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 December 31, 2020 and September 30, 2020: December 31, 2020 September 30, 2020 (In thousands) Carrying Amount $ 5,160,000 $ 4,560,000 Fair Value $ 6,294,671 $ 5,597,183

Nature of Business (Details)

Nature of Business (Details) customer in Millions	Dec. 31, 2020stateregulated_distribution_divisioncustomer
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of customers serviced | customer	3
Number of regulated distribution divisions | regulated_distribution_division	6
Number of states with service areas | state	8

Unaudited Financial Informati_4

Unaudited Financial Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2020	Sep. 30, 2020
Regulatory Asset [Line Items]
Regulatory assets	$ 353,246	$ 414,641
Regulatory Liabilities [Line Items]
Regulatory liabilities	1,351,370	1,367,013
Regulatory excess deferred taxes
Regulatory Liabilities [Line Items]
Regulatory liabilities	713,993	718,651
Regulatory excess deferred taxes | Other Current Liabilities
Regulatory Liabilities [Line Items]
Regulatory liabilities	$ 18,800	20,900
Regulatory excess deferred taxes | Other Current Liabilities | Minimum
Regulatory Liabilities [Line Items]
Return basis, term	15 years
Regulatory excess deferred taxes | Other Current Liabilities | Maximum
Regulatory Liabilities [Line Items]
Return basis, term	69 years
Regulatory cost of removal obligation
Regulatory Liabilities [Line Items]
Regulatory liabilities	$ 527,087	531,096
Deferred gas costs
Regulatory Liabilities [Line Items]
Regulatory liabilities	15,196	19,985
Asset retirement obligation
Regulatory Liabilities [Line Items]
Regulatory liabilities	20,348	20,348
APT annual adjustment mechanism
Regulatory Liabilities [Line Items]
Regulatory liabilities	55,313	57,379
Other
Regulatory Liabilities [Line Items]
Regulatory liabilities	19,433	19,554
Pension and postretirement benefit costs
Regulatory Asset [Line Items]
Regulatory assets	146,734	149,089
Infrastructure mechanisms
Regulatory Asset [Line Items]
Regulatory assets	155,526	183,943
Deferred gas costs
Regulatory Asset [Line Items]
Regulatory assets	11,322	40,593
Recoverable loss on reacquired debt
Regulatory Asset [Line Items]
Regulatory assets	4,529	4,894
Deferred pipeline record collection costs
Regulatory Asset [Line Items]
Regulatory assets	30,166	29,839
Other
Regulatory Asset [Line Items]
Regulatory assets	$ 4,969	$ 6,283

Segment Information (Details)

Segment Information (Details) $ in Thousands	3 Months Ended
	Dec. 31, 2020USD ($)state	Dec. 31, 2019USD ($)	Sep. 30, 2020USD ($)
Segment Reporting Information [Line Items]
Number of states with service areas | state	8
Segment Reporting Information Profit Loss [Abstract]
Operating revenues	$ 914,480	$ 875,563
Purchased gas cost	288,260	296,868
Operation and maintenance expense	138,643	152,245
Depreciation and amortization expense	115,285	105,062
Taxes, other than income	73,452	68,607
Operating income	298,840	252,781
Other non-operating income	6,072	4,887
Interest charges	22,010	27,229
Income before income taxes	282,902	230,439
Income tax (benefit) expense	65,224	51,766
Net income	217,678	178,673
Capital expenditures	456,809	529,186
Segment Reporting Information, Balance Sheet [Abstract]
Property, plant and equipment, net	13,762,143		$ 13,355,347
Total assets	16,475,879		15,359,032
Distribution
Segment Reporting Information Profit Loss [Abstract]
Operating revenues	875,887	827,840
Pipeline and Storage
Segment Reporting Information Profit Loss [Abstract]
Operating revenues	38,593	47,723
Operating Segments | Distribution
Segment Reporting Information Profit Loss [Abstract]
Operating revenues	876,650	828,504
Purchased gas cost	411,072	397,558
Operation and maintenance expense	108,802	114,352
Depreciation and amortization expense	82,870	76,074
Taxes, other than income	64,352	60,243
Operating income	209,554	180,277
Other non-operating income	835	1,954
Interest charges	10,712	16,362
Income before income taxes	199,677	165,869
Income tax (benefit) expense	45,985	36,112
Net income	153,692	129,757
Capital expenditures	306,016	404,247
Segment Reporting Information, Balance Sheet [Abstract]
Property, plant and equipment, net	10,235,658		9,944,978
Total assets	15,694,179		14,578,176
Operating Segments | Pipeline and Storage
Segment Reporting Information Profit Loss [Abstract]
Operating revenues	159,713	148,176
Purchased gas cost	(1,244)	99
Operation and maintenance expense	30,156	38,221
Depreciation and amortization expense	32,415	28,988
Taxes, other than income	9,100	8,364
Operating income	89,286	72,504
Other non-operating income	5,237	2,933
Interest charges	11,298	10,867
Income before income taxes	83,225	64,570
Income tax (benefit) expense	19,239	15,654
Net income	63,986	48,916
Capital expenditures	150,793	124,939
Segment Reporting Information, Balance Sheet [Abstract]
Property, plant and equipment, net	3,526,485		3,410,369
Total assets	3,757,875		3,647,907
Eliminations
Segment Reporting Information Profit Loss [Abstract]
Operating revenues	(121,883)	(101,117)
Purchased gas cost	(121,568)	(100,789)
Operation and maintenance expense	(315)	(328)
Depreciation and amortization expense	0	0
Taxes, other than income	0	0
Operating income	0	0
Other non-operating income	0	0
Interest charges	0	0
Income before income taxes	0	0
Income tax (benefit) expense	0	0
Net income	0	0
Capital expenditures	0	0
Segment Reporting Information, Balance Sheet [Abstract]
Property, plant and equipment, net	0		0
Total assets	(2,976,175)		$ (2,867,051)
Eliminations | Distribution
Segment Reporting Information Profit Loss [Abstract]
Operating revenues	763	664
Eliminations | Pipeline and Storage
Segment Reporting Information Profit Loss [Abstract]
Operating revenues	$ 121,120	$ 100,453

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Basic Earnings Per Share
Net income	$ 217,678	$ 178,673
Less: Income allocated to participating securities	151	136
Income available to common shareholders	$ 217,527	$ 178,537
Basic weighted average shares outstanding (in shares)	127,034	121,113
Net income per share - Basic (USD per share)	$ 1.71	$ 1.47
Diluted Earnings Per Share
Income available to common shareholders	$ 217,527	$ 178,537
Effect of dilutive shares	0	0
Income available to common shareholders	$ 217,527	$ 178,537
Basic weighted average shares outstanding (in shares)	127,034	121,113
Dilutive shares (in shares)	0	246
Diluted weighted average shares outstanding (in shares)	127,034	121,359
Net income per share - Diluted (USD per share)	$ 1.71	$ 1.47

Revenue and Accounts Receivab_3

Revenue and Accounts Receivable - Disaggregation (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Total operating revenues	$ 914,480	$ 875,563
Regulatory mechanism threshold (in percent)	75.00%	75.00%
Distribution
Disaggregation of Revenue [Line Items]
Total operating revenues	$ 875,887	$ 827,840
Pipeline and Storage
Disaggregation of Revenue [Line Items]
Total operating revenues	38,593	47,723
Operating Segments | Distribution
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	868,714	834,763
Alternative revenue program revenues	7,441	(6,751)
Regulated Operating Revenue, Other	495	492
Total operating revenues	876,650	828,504
Operating Segments | Distribution | Gas sales revenues:
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	838,551	801,337
Operating Segments | Distribution | Gas sales revenues: | Residential
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	591,834	552,076
Operating Segments | Distribution | Gas sales revenues: | Commercial
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	208,947	211,314
Operating Segments | Distribution | Gas sales revenues: | Industrial
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	24,708	24,925
Operating Segments | Distribution | Gas sales revenues: | Public authority and other
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	13,062	13,022
Operating Segments | Distribution | Transportation revenues
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	27,767	26,640
Operating Segments | Distribution | Miscellaneous revenues
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	2,396	6,786
Operating Segments | Pipeline and Storage
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	169,909	157,165
Alternative revenue program revenues	(10,196)	(8,989)
Regulated Operating Revenue, Other	0	0
Total operating revenues	159,713	148,176
Operating Segments | Pipeline and Storage | Gas sales revenues:
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0	0
Operating Segments | Pipeline and Storage | Gas sales revenues: | Residential
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0	0
Operating Segments | Pipeline and Storage | Gas sales revenues: | Commercial
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0	0
Operating Segments | Pipeline and Storage | Gas sales revenues: | Industrial
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	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
Operating Segments | Pipeline and Storage | Transportation revenues
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	164,761	152,010
Operating Segments | Pipeline and Storage | Miscellaneous revenues
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	$ 5,148	$ 5,155

Revenue and Accounts Receivab_4

Revenue and Accounts Receivable - Allowance for Credit Loss (Details) $ in Thousands	3 Months Ended
	Dec. 31, 2020USD ($)
Revenue from Contract with Customer [Abstract]
Percent of customers excluded	78.00%
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 29,949
Current period provisions	6,937
Write-offs charged against allowance	(2,288)
Recoveries of amounts previously written off	491
Ending balance	$ 35,089

Debt - Schedule of Long-term De

Debt - Schedule of Long-term Debt Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Oct. 01, 2020	Sep. 30, 2020
Debt Instrument [Line Items]
Long-term debt	$ 5,160,000		$ 4,560,000
Finance lease obligations	8,608		8,631
Total long-term debt	5,168,608		4,568,631
Original issue discount on unsecured senior notes and debentures	3,090		583
Debt issuance cost	40,485		36,104
Current maturities	171		165
Long-term debt, noncurrent	$ 5,124,862		4,531,779
Unsecured 3.00% Senior Notes, due 2027
Debt Instrument [Line Items]
Interest rate	3.00%
Long-term debt	$ 500,000		500,000
Unsecured 2.625% Senior Notes, due 2029
Debt Instrument [Line Items]
Interest rate	2.625%
Long-term debt	$ 300,000		300,000
Unsecured 1.50% Senior Notes, due 2031
Debt Instrument [Line Items]
Interest rate	1.50%	1.50%
Long-term debt	$ 600,000		0
Unsecured 5.95% Senior Notes, due 2034
Debt Instrument [Line Items]
Interest rate	5.95%
Long-term debt	$ 200,000		200,000
Unsecured 5.50% Senior Notes, due 2041
Debt Instrument [Line Items]
Interest rate	5.50%
Long-term debt	$ 400,000		400,000
Unsecured 4.15% Senior Notes, due 2043
Debt Instrument [Line Items]
Interest rate	4.15%
Long-term debt	$ 500,000		500,000
Unsecured 4.125% Senior Notes, due 2044
Debt Instrument [Line Items]
Interest rate	4.125%
Long-term debt	$ 750,000		750,000
Unsecured 4.30% Senior Notes, due 2048
Debt Instrument [Line Items]
Interest rate	4.30%
Long-term debt	$ 600,000		600,000
Unsecured 4.125% Senior Notes, due 2049
Debt Instrument [Line Items]
Interest rate	4.125%
Long-term debt	$ 450,000		450,000
Unsecured 3.375% Senior Notes, due 2049
Debt Instrument [Line Items]
Interest rate	3.375%
Long-term debt	$ 500,000		500,000
Floating-rate term loan, due 2022
Debt Instrument [Line Items]
Long-term debt	$ 200,000		200,000
Medium-term note Series A, 1995-1, 6.67%, due 2025
Debt Instrument [Line Items]
Interest rate	6.67%
Long-term debt	$ 10,000		10,000
Unsecured 6.75% Debentures, due 2028
Debt Instrument [Line Items]
Interest rate	6.75%
Long-term debt	$ 150,000		$ 150,000

Debt - Narrative (Details)

Debt - Narrative (Details)	Oct. 01, 2020USD ($)	Dec. 31, 2020USD ($)credit_facility	Dec. 31, 2019USD ($)	Sep. 30, 2020USD ($)
Line Of Credit Facility [Line Items]
Proceeds from issuance of long-term debt		$ 597,390,000	$ 799,450,000
Maximum borrowing capacity		$ 2,200,000,000
Maximum debt-to-total-capitalization ratio		70.00%
Debt-to-total-capitalization ratio		0.43
Minimum
Line Of Credit Facility [Line Items]
Equity-to-total-capitalization ratio		50.00%
Outstanding indebtedness		$ 15,000,000
Maximum
Line Of Credit Facility [Line Items]
Equity-to-total-capitalization ratio		60.00%
Outstanding indebtedness		$ 100,000,000
Revolving Credit Facility
Line Of Credit Facility [Line Items]
Number of credit facilities | credit_facility		4
Unsecured 1.50% Senior Notes, due 2031
Line Of Credit Facility [Line Items]
Debt instrument, face amount	$ 600,000,000
Interest rate	1.50%	1.50%
Proceeds from issuance of long-term debt	$ 592,300,000
Effective interest rate	1.71%
Five Year Unsecured Revolving Credit Agreement
Line Of Credit Facility [Line Items]
Outstanding commercial paper		$ 0		$ 0
Five Year Unsecured Revolving Credit Agreement | Commercial Paper
Line Of Credit Facility [Line Items]
Maximum borrowing capacity		1,500,000,000
Accordion feature		250,000,000
Maximum borrowing capacity post accordion feature		$ 1,750,000,000
Debt agreement term		5 years
$600 Million Revolving Credit Facility | Revolving Credit Facility
Line Of Credit Facility [Line Items]
Maximum borrowing capacity		$ 600,000,000
Debt agreement term		364 days
Outstanding borrowings		$ 0
$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
$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
$50 Million Revolving Credit Facility | Line of Credit
Line Of Credit Facility [Line Items]
Outstanding borrowings		$ 0
LIBOR | Five Year Unsecured Revolving Credit Agreement | Commercial Paper | Minimum
Line Of Credit Facility [Line Items]
Interest rate spread		0.00%
LIBOR | Five Year Unsecured Revolving Credit Agreement | Commercial Paper | Maximum
Line Of Credit Facility [Line Items]
Interest rate spread		1.25%
LIBOR | $600 Million Revolving Credit Facility | Revolving Credit Facility | Minimum
Line Of Credit Facility [Line Items]
Interest rate spread		0.00%
LIBOR | $600 Million Revolving Credit Facility | Revolving Credit Facility | Maximum
Line Of Credit Facility [Line Items]
Interest rate spread		1.25%

Shareholders' Equity - Componen

Shareholders' Equity - Components of Equity (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock outstanding, beginning balance (in shares)	125,882,477
Shareholders' equity, beginning balance	$ 6,791,203	$ 5,750,223
Net income	217,678	178,673
Other comprehensive income (loss)	60,121	1,052
Cash dividends	(79,023)	(69,557)
Public and other stock offerings	220,009	263,272
Stock-based compensation plans	$ 3,168	4,112
Common stock outstanding, ending balance (in shares)	128,152,961
Shareholders' equity, ending balance	$ 7,213,156	$ 6,127,775
Cash dividends per share (USD per share)	$ 0.625	$ 0.575
Common stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock outstanding, beginning balance (in shares)	125,882,477	119,338,925
Shareholders' equity, beginning balance	$ 629	$ 597
Public and other stock offerings (in shares)	2,126,118	2,758,929
Public and other stock offerings	$ 11	$ 13
Stock-based compensation plans (in shares)	144,366	164,549
Stock-based compensation plans	$ 1	$ 1
Common stock outstanding, ending balance (in shares)	128,152,961	122,262,403
Shareholders' equity, ending balance	$ 641	$ 611
Additional Paid-in Capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shareholders' equity, beginning balance	4,377,149	3,712,194
Public and other stock offerings	219,998	263,259
Stock-based compensation plans	3,167	4,111
Shareholders' equity, ending balance	4,600,314	3,979,564
Accumulated Other Comprehensive Income (Loss)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shareholders' equity, beginning balance	(57,589)	(114,583)
Other comprehensive income (loss)	60,121	1,052
Shareholders' equity, ending balance	2,532	(113,531)
Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shareholders' equity, beginning balance	2,471,014	2,152,015
Net income	217,678	178,673
Cash dividends	(79,023)	(69,557)
Shareholders' equity, ending balance	$ 2,609,669	$ 2,261,131

Shareholders' Equity - Narrativ

Shareholders' Equity - Narrative (Details) - USD ($)	3 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Feb. 11, 2020
Class of Stock [Line Items]
Forward contract indexed to issuer's equity, settlement alternatives, cash, at fair value	$ 246,834,000
Net proceeds from equity offering	216,002,000	$ 259,005,000
Shelf Registration Statement
Class of Stock [Line Items]
Debt and equity securities authorized for issuance			$ 4,000,000,000
Debt and equity securities authorized for issuance value remaining	$ 2,400,000,000
At-The-Market
Class of Stock [Line Items]
Forward sales equity agreement (in shares)	1,201,674
Forward contract indexed to issuer's equity, settlement alternatives, cash, at fair value	$ 121,800,000
Stock issued during period, new issues (in shares)	2,085,492
Net proceeds from equity offering	$ 216,000,000
Equity available for issuance	$ 430,000,000

Shareholders' Equity - Forward

Shareholders' Equity - Forward Sales Agreement (Details) $ / shares in Units, $ in Thousands	3 Months Ended
	Dec. 31, 2020USD ($)$ / sharesshares
Class of Stock [Line Items]
Shares Available (in shares) | shares	2,452,177
Net Proceeds Available | $	$ 246,834
Forward Price (dollars per share) | $ / shares	$ 100.66
Forward Sales Equity Agreement, Maturing Quarter ended June 30, 2021
Class of Stock [Line Items]
Shares Available (in shares) | shares	1,060,660
Net Proceeds Available | $	$ 107,255
Forward Price (dollars per share) | $ / shares	$ 101.12
Forward Sales Equity Agreement, Maturing Quarter ended September 30, 2021
Class of Stock [Line Items]
Shares Available (in shares) | shares	1,391,517
Net Proceeds Available | $	$ 139,579
Forward Price (dollars per share) | $ / shares	$ 100.31

Shareholders' Equity - Schedule

Shareholders' Equity - Schedule of AOCI (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Shareholders' equity, beginning balance	$ 6,791,203	$ 5,750,223
Other comprehensive income (loss) before reclassifications	58,979	(1)
Amounts reclassified from accumulated other comprehensive income	1,142	1,053
Net current-period other comprehensive income (loss)	60,121	1,052
Shareholders' equity, ending balance	7,213,156	6,127,775
Available- for-Sale Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Shareholders' equity, beginning balance	238	132
Other comprehensive income (loss) before reclassifications	(63)	(1)
Amounts reclassified from accumulated other comprehensive income	0	0
Net current-period other comprehensive income (loss)	(63)	(1)
Shareholders' equity, ending balance	175	131
Interest Rate Agreement Cash Flow Hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Shareholders' equity, beginning balance	(57,827)	(114,715)
Other comprehensive income (loss) before reclassifications	59,042	0
Amounts reclassified from accumulated other comprehensive income	1,142	1,053
Net current-period other comprehensive income (loss)	60,184	1,053
Shareholders' equity, ending balance	2,357	(113,662)
Accumulated Other Comprehensive Income (Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Shareholders' equity, beginning balance	(57,589)	(114,583)
Net current-period other comprehensive income (loss)	60,121	1,052
Shareholders' equity, ending balance	$ 2,532	$ (113,531)

Interim Pension and Other Pos_3

Interim Pension and Other Postretirement Benefit Plan Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Contribution to postretirement medical plans	$ 4,100
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	4,612	$ 4,653
Interest cost	5,028	5,843
Expected return on assets	(6,978)	(7,079)
Amortization of prior service cost (credit)	(58)	(58)
Amortization of actuarial (gain) loss	3,172	(1,271)
Net periodic pension cost	5,776	2,088
Other Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	4,306	3,366
Interest cost	2,660	2,653
Expected return on assets	(2,614)	(2,625)
Amortization of prior service cost (credit)	43	43
Amortization of actuarial (gain) loss	0	(334)
Net periodic pension cost	4,395	$ 3,103
Minimum | Other Benefits
Defined Benefit Plan Disclosure [Line Items]
Expected future contributions	15,000
Maximum | Other Benefits
Defined Benefit Plan Disclosure [Line Items]
Expected future contributions	$ 25,000

Commitments and Contingencies (

Commitments and Contingencies (Details)	3 Months Ended
	Dec. 31, 2020USD ($)
Commitments and Contingencies Disclosure [Abstract]
Self-insurance retention expense	$ 1,000,000

Financial Instruments - Narrati

Financial Instruments - Narrative (Details)	3 Months Ended		12 Months Ended
	Dec. 31, 2020USD ($)Bcf	Dec. 31, 2019USD ($)	Sep. 30, 2020USD ($)Bcf
Derivative [Line Items]
Contract netting	$ 0	$ 0	$ 0
Cash collateral	0	0
Net gain (loss) on settled interest rate agreements	(1,500,000)	$ (1,400,000)
Net realized gain (loss) in AOCI	$ (113,400,000)
Gas Purchases | Not Designated as Hedging Instrument | Commodity contracts
Derivative [Line Items]
Hedging percent			39.00%
Energy measure | Bcf			15.8
Gas Purchases | Not Designated as Hedging Instrument | Commodity contracts | Long
Derivative [Line Items]
Energy measure | Bcf	11.64
Minimum | Gas Purchases | Not Designated as Hedging Instrument | Commodity contracts
Derivative [Line Items]
Hedging percent	25.00%
Maximum | Gas Purchases | Not Designated as Hedging Instrument | Commodity contracts
Derivative [Line Items]
Hedging percent	50.00%

Financial Instruments - Schedul

Financial Instruments - Schedule of Derivative Instruments in Statement of Financial Position, Fair Value (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Sep. 30, 2020
Derivatives Fair Value [Line Items]
Net Financial Instruments, Assets	$ 150,398	$ 80,678
Net Financial Instruments, Liabilities	(1,843)	(2,015)
Designated as Hedging Instrument
Derivatives Fair Value [Line Items]
Gross Financial Instruments, Assets	149,162	73,055
Gross Financial Instruments, Liabilities	0	0
Designated as Hedging Instrument | Other Current Assets | Interest rate contracts
Derivatives Fair Value [Line Items]
Gross Financial Instruments, Assets	56,484
Designated as Hedging Instrument | Other Current Liabilities | Interest rate contracts
Derivatives Fair Value [Line Items]
Gross Financial Instruments, Liabilities	0
Designated as Hedging Instrument | Deferred Charges and Other Assets | Interest rate contracts
Derivatives Fair Value [Line Items]
Gross Financial Instruments, Assets	92,678	73,055
Designated as Hedging Instrument | Deferred Credits and Other Liabilities | Interest rate contracts
Derivatives Fair Value [Line Items]
Gross Financial Instruments, Liabilities	0	0
Not Designated as Hedging Instrument
Derivatives Fair Value [Line Items]
Gross Financial Instruments, Assets	1,236	7,623
Gross Financial Instruments, Liabilities	(1,843)	(2,015)
Not Designated as Hedging Instrument | Other Current Assets | Commodity contracts
Derivatives Fair Value [Line Items]
Gross Financial Instruments, Assets	993	5,687
Not Designated as Hedging Instrument | Other Current Liabilities | Commodity contracts
Derivatives Fair Value [Line Items]
Gross Financial Instruments, Liabilities	(1,843)	(2,015)
Not Designated as Hedging Instrument | Deferred Charges and Other Assets | Commodity contracts
Derivatives Fair Value [Line Items]
Gross Financial Instruments, Assets	243	1,936
Not Designated as Hedging Instrument | Deferred Credits and Other Liabilities | Commodity contracts
Derivatives Fair Value [Line Items]
Gross Financial Instruments, Liabilities	$ 0	$ 0

Financial Instruments - Sched_2

Financial Instruments - Schedule of Cash Flow Hedges Included in Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Increase in fair value:
Interest rate agreements	$ 59,042	$ 0
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Interest rate agreements	1,142	1,053
Total other comprehensive income (loss) from hedging, net of tax	$ 60,184	$ 1,053

Financial Instruments - Sched_3

Financial Instruments - Schedule Of Expected Deferred Gains (Losses) Recognition (Details) $ in Thousands	3 Months Ended
	Dec. 31, 2020USD ($)
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Next twelve months	$ (4,566)
Thereafter	(108,794)
Total	$ (113,360)

Financial Instruments - Forward

Financial Instruments - Forward Starting Derivatives (Details) - Designated as Hedging Instrument - Forward Interest Rate Swap	Dec. 31, 2020USD ($)
Derivative [Line Items]
Derivative, notional amount	$ 1,050,000
Unsecured Senior Notes In Fiscal 2022
Derivative [Line Items]
Derivative, notional amount	$ 450,000
Interest rate	1.33%
Unsecured Senior Notes In Fiscal 2023
Derivative [Line Items]
Derivative, notional amount	$ 300,000
Interest rate	1.36%
Unsecured Senior Notes In Fiscal 2025
Derivative [Line Items]
Derivative, notional amount	$ 300,000
Interest rate	1.35%

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis (Details) - USD ($)	Dec. 31, 2020	Sep. 30, 2020	Dec. 31, 2019
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Netting and Cash Collateral	$ 0	$ 0	$ 0
Financial instruments net assets	150,398,000	80,678,000
Debt and equity securities	106,026,000	103,952,000
Total assets	256,424,000	184,630,000
Netting and Cash Collateral	0	0
Financial instruments net liability	1,843,000	2,015,000
Registered investment companies
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Equity Securities	35,518,000	37,831,000
Bond mutual funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Equity Securities	30,204,000	29,166,000
Bonds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Debt securities	34,142,000	32,900,000
Money market funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Equity Securities	6,162,000	4,055,000
Fair Value Inputs 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	65,722,000	66,997,000
Total assets	65,722,000	66,997,000
Financial instruments gross liability	0	0
Fair Value Inputs Level 1 | Registered investment companies
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Equity Securities	35,518,000	37,831,000
Fair Value Inputs Level 1 | Bond mutual funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Equity Securities	30,204,000	29,166,000
Fair Value Inputs Level 1 | Bonds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Debt securities	0	0
Fair Value Inputs Level 1 | Money market funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Equity Securities	0	0
Fair Value Inputs Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Financial instruments gross assets	150,398,000	80,678,000
Debt and equity securities	40,304,000	36,955,000
Total assets	190,702,000	117,633,000
Financial instruments gross liability	1,843,000	2,015,000
Fair Value Inputs Level 2 | Registered investment companies
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Equity Securities	0	0
Fair Value Inputs Level 2 | Bond mutual funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Equity Securities	0	0
Fair Value Inputs Level 2 | Bonds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Debt securities	34,142,000	32,900,000
Fair Value Inputs Level 2 | Money market funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Equity Securities	6,162,000	4,055,000
Fair Value 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
Fair Value Inputs Level 3 | Registered investment companies
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Equity Securities	0	0
Fair Value Inputs Level 3 | Bond mutual funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Equity Securities	0	0
Fair Value Inputs Level 3 | Bonds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Debt securities	0	0
Fair Value 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 ($)	Dec. 31, 2020	Sep. 30, 2020
Schedule of Available For Sale Securities [Abstract]
Allowance for credit losses	$ 0
Cost Basis	$ 33,900,000	$ 32,600,000

Fair Value Measurements - Sch_2

Fair Value Measurements - Schedule of Debt Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Sep. 30, 2020
Fair Value Disclosures [Abstract]
Carrying Amount	$ 5,160,000	$ 4,560,000
Fair Value	$ 6,294,671	$ 5,597,183