National Fuel Gas (NFG) 10-Q 7 May 21 2021 Q2 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - $ / shares	6 Months Ended
	Mar. 31, 2021	Apr. 30, 2021
Cover [Abstract]
Amendment Flag	false
Current Fiscal Year End Date	--09-30
Document Fiscal Period Focus	Q2
Document Fiscal Year Focus	2021
Document Period End Date	Mar. 31, 2021
Document Quarterly Report	true
Document Transition Report	false
Document Type	10-Q
Entity Address, Address Line One	6363 Main Street
Entity Address, City or Town	Williamsville,
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	14221
Entity Central Index Key	0000070145
Entity Common Stock, Shares Outstanding		91,172,701
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Emerging Growth Company	false
Entity File Number	1-3880
Entity Filer Category	Large Accelerated Filer
Entity Incorporation, State or Country Code	NJ
Entity Registrant Name	NATIONAL FUEL GAS COMPANY
Entity Shell Company	false
Entity Small Business	false
Entity Tax Identification Number	13-1086010
City Area Code	716
Local Phone Number	857-7000
Title of 12(b) Security	Common Stock, par value $1.00 per share
Trading Symbol	NFG
Security Exchange Name	NYSE
Entity Listing, Par Value Per Share	$ 1

Consolidated Statements Of Inco

Consolidated Statements Of Income And Earnings Reinvested In The Business (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020
INCOME
Operating Revenues	$ 551,115	$ 491,095	$ 992,275	$ 935,283
Operating Expenses:
Purchased Gas	106,661	118,270	158,280	210,542
Property, Franchise and Other Taxes	23,987	22,743	46,768	45,887
Depreciation, Depletion and Amortization	84,342	77,912	167,462	152,830
Impairment of Oil and Gas Producing Properties	0	177,761	76,152	177,761
Total Operating Expenses	337,076	515,675	685,759	811,843
Gain on Sale of Timber Properties	0	0	51,066	0
Operating Income (Loss)	214,039	(24,580)	357,582	123,440
Other Income (Expense):
Other Income (Deductions)	(10,875)	(17,480)	(13,051)	(20,520)
Interest Expense on Long-Term Debt	(48,820)	(25,270)	(81,076)	(50,713)
Other Interest Expense	(1,698)	(1,892)	(3,618)	(3,443)
Income (Loss) Before Income Taxes	152,646	(69,222)	259,837	48,764
Income Tax Expense	40,210	36,846	69,627	68,241
Net Income (Loss) Available for Common Stock	112,436	(106,068)	190,210	(19,477)
EARNINGS REINVESTED IN THE BUSINESS
Balance at Beginning of Period	1,028,844	1,320,592	991,630	1,272,601
Beginning Retained Earnings Unappropriated And Current Period Net Income	1,141,280	1,214,524	1,181,840	1,253,124
Dividends on Common Stock	(40,562)	(37,654)	(81,122)	(75,304)
Balance at March 31	$ 1,100,718	$ 1,176,870	$ 1,100,718	$ 1,176,870
Earnings (Loss) Per Common Share, Basic:
Net Income (Loss) Available for Common Stock (in dollars per share)	$ 1.23	$ (1.23)	$ 2.09	$ (0.23)
Earnings (Loss) Per Common Share, Diluted:
Net Income (Loss) Available for Common Stock (in dollars per share)	$ 1.23	$ (1.23)	$ 2.08	$ (0.23)
Weighted Average Common Shares Outstanding:
Used in Basic Calculation (shares)	91,163,291	86,561,066	91,084,620	86,469,258
Used in Diluted Calculation (shares)	91,645,679	86,561,066	91,581,918	86,469,258
Dividends Per Common Share:
Dividends Declared (in dollars per share)	$ 0.445	$ 0.435	$ 0.890	$ 0.870
Utility and Energy Marketing [Member]
INCOME
Operating Revenues	$ 270,849	$ 282,634	$ 460,315	$ 510,660
Operating Expenses:
Operation and Maintenance	52,058	51,725	96,944	94,981
Exploration and Production and Other [Member]
INCOME
Operating Revenues	220,281	156,542	412,316	323,735
Operating Expenses:
Operation and Maintenance	41,895	39,959	83,922	76,652
Pipeline and Storage and Gathering [Member]
INCOME
Operating Revenues	59,985	51,919	119,644	100,888
Operating Expenses:
Operation and Maintenance	28,133	27,305	56,231	53,190
Guidance for Hedging [Member] | Cumulative Effect of Adoption of Authoritative Guidance [Member]
EARNINGS REINVESTED IN THE BUSINESS
Balance at Beginning of Period	$ 0	$ 0	$ 0	$ (950)

Consolidated Statements Of Comp

Consolidated Statements Of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020
Statement of Comprehensive Income [Abstract]
Net Income (Loss) Available for Common Stock	$ 112,436	$ (106,068)	$ 190,210	$ (19,477)
Other Comprehensive Income (Loss), Before Tax:
Unrealized Gain (Loss) on Derivative Financial Instruments Arising During the Period	(34,373)	76,304	13,648	76,799
Reclassification Adjustment for Realized (Gains) Losses on Derivative Financial Instruments in Net Income	3,666	(25,034)	3,977	(32,386)
Cumulative Effect of Adoption of Authoritative Guidance for Hedging	0	0	0	1,313
Other Comprehensive Income (Loss), Before Tax	(30,707)	51,270	17,625	45,726
Income Tax Expense (Benefit) Related to Unrealized Gain (Loss) on Derivative Financial Instruments Arising During the Period	(9,470)	20,854	3,760	20,974
Reclassification Adjustment for Income Tax Benefit (Expense) on Realized Losses (Gains) from Derivative Financial Instruments in Net Income	1,010	(6,817)	1,096	(8,849)
Income Tax Benefit (Expense) on Cumulative Effect of Adoption of Authoritative Guidance for Hedging	0	0	0	363
Income Taxes – Net	(8,460)	14,037	4,856	12,488
Other Comprehensive Income (Loss)	(22,247)	37,233	12,769	33,238
Comprehensive Income (Loss)	$ 90,189	$ (68,835)	$ 202,979	$ 13,761

Consolidated Balance Sheets (Un

Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2021	Sep. 30, 2020
ASSETS
Property, Plant and Equipment	$ 12,648,604	$ 12,351,852
Less - Accumulated Depreciation, Depletion and Amortization	6,572,534	6,353,785
Property, Plant and Equipment, Net, Total	6,076,070	5,998,067
Assets Held for Sale, Net	0	53,424
Current Assets
Cash and Temporary Cash Investments	80,467	20,541
Receivables - Net of Allowance for Uncollectible Accounts of $30,128 and $22,810, Respectively	229,479	143,583
Unbilled Revenue	32,685	17,302
Gas Stored Underground	5,745	33,338
Materials, Supplies and Emission Allowances	52,212	51,877
Unrecovered Purchased Gas Costs	479	0
Other Current Assets	56,117	47,557
Total Current Assets	457,184	314,198
Other Assets
Recoverable Future Taxes	117,300	118,310
Unamortized Debt Expense	11,443	12,297
Other Regulatory Assets	147,099	156,106
Deferred Charges	60,454	67,131
Other Investments	147,421	154,502
Goodwill	5,476	5,476
Prepaid Post-Retirement Benefit Costs	89,101	76,035
Fair Value of Derivative Financial Instruments	4,104	9,308
Other	0	81
Total Other Assets	582,398	599,246
Total Assets	7,115,652	6,964,935
Capitalization:
Common Stock, $1 Par Value Authorized - 200,000,000 Shares; Issued and Outstanding - 91,163,797 Shares and 90,954,696 Shares, Respectively	91,164	90,955
Paid in Capital	1,009,075	1,004,158
Earnings Reinvested in the Business	1,100,718	991,630
Accumulated Other Comprehensive Loss	(101,988)	(114,757)
Total Comprehensive Shareholders’ Equity	2,098,969	1,971,986
Long-Term Debt, Net of Current Portion and Unamortized Discount and Debt Issuance Costs	2,627,033	2,629,576
Total Capitalization	4,726,002	4,601,562
Current and Accrued Liabilities
Notes Payable to Banks and Commercial Paper	0	30,000
Accounts Payable	107,305	134,126
Amounts Payable to Customers	19,768	10,788
Dividends Payable	40,562	40,475
Interest Payable on Long-Term Debt	17,663	27,521
Customer Advances	0	15,319
Customer Security Deposits	19,503	17,199
Other Accruals and Current Liabilities	176,940	140,176
Fair Value of Derivative Financial Instruments	21,231	43,969
Total Current and Accrued Liabilities	402,972	459,573
Deferred Credits
Deferred Income Taxes	763,441	696,054
Taxes Refundable to Customers	355,375	357,508
Cost of Removal Regulatory Liability	237,867	230,079
Other Regulatory Liabilities	177,685	161,573
Pension and Other Post-Retirement Liabilities	118,804	127,181
Asset Retirement Obligations	192,127	192,228
Other Deferred Credits	141,379	139,177
Total Deferred Credits	1,986,678	1,903,800
Commitments and Contingencies (Note 8)	0	0
Total Capitalization and Liabilities	$ 7,115,652	$ 6,964,935

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2021	Sep. 30, 2020
Statement of Financial Position [Abstract]
Receivables, Allowance for Uncollectible Accounts	$ 30,128	$ 22,810
Common Stock, Par Value	$ 1	$ 1
Common Stock, Shares Authorized	200,000,000	200,000,000
Common Stock, Shares Issued	91,163,797	90,954,696
Common Stock, Shares Outstanding	91,163,797	90,954,696

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
OPERATING ACTIVITIES
Net Income (Loss) Available for Common Stock	$ 190,210	$ (19,477)
Adjustments to Reconcile Net Income (Loss) to Net Cash Provided by Operating Activities:
Gain on Sale of Timber Properties	(51,066)	0
Impairment of Oil and Gas Producing Properties	76,152	177,761
Depreciation, Depletion and Amortization	167,462	152,830
Deferred Income Taxes	61,408	104,883
Premium Paid on Early Redemption of Debt	15,715	0
Stock-Based Compensation	8,657	7,580
Other	6,742	9,800
Change in:
Receivables and Unbilled Revenue	(101,159)	(58,248)
Gas Stored Underground and Materials, Supplies and Emission Allowances	27,258	20,086
Unrecovered Purchased Gas Costs	(479)	2,246
Other Current Assets	(8,447)	(3,134)
Accounts Payable	8,613	(5,465)
Amounts Payable to Customers	8,980	13,196
Customer Advances	(15,319)	(12,429)
Customer Security Deposits	2,304	(1,211)
Other Accruals and Current Liabilities	9,058	9,076
Other Assets	11,039	(10,359)
Other Liabilities	5	3,857
Net Cash Provided by Operating Activities	417,133	390,992
INVESTING ACTIVITIES
Capital Expenditures	(338,867)	(395,486)
Net Proceeds from Sale of Timber Properties	104,582	0
Other	12,095	4,167
Net Cash Used in Investing Activities	(222,190)	(391,319)
Financing Activities
Changes in Notes Payable to Banks and Commercial Paper	(30,000)	174,800
Net Proceeds from Issuance of Long-Term Debt	495,267	0
Reduction of Long-term Debt	(515,715)	0
Dividends Paid on Common Stock	(81,035)	(75,197)
Net Repurchases of Common Stock	(3,534)	(4,153)
Net Cash Provided by (Used in) Financing Activities	(135,017)	95,450
Net Increase in Cash, Cash Equivalents, and Restricted Cash	59,926	95,123
Cash, Cash Equivalents and Restricted Cash at October 1	20,541	27,260
Cash, Cash Equivalents and Restricted Cash at March 31	80,467	122,383
Supplemental Disclosure of Cash Flow Information, Non-Cash Investing Activities:
Non-Cash Capital Expenditures	$ 68,073	$ 59,490

Summary Of Significant Accounti

Summary Of Significant Accounting Policies	6 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Summary Of Significant Accounting Policies	Summary of Significant Accounting Policies Principles of Consolidation. The Company consolidates all entities in which it has a controlling financial interest. All significant intercompany balances and transactions are eliminated. The Company uses proportionate consolidation when accounting for drilling arrangements related to oil and gas producing properties accounted for under the full cost method of accounting. The preparation of the consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Earnings for Interim Periods. The Company, in its opinion, has included all adjustments (which consist of only normally recurring adjustments, unless otherwise disclosed in this Form 10-Q) that are necessary for a fair statement of the results of operations for the reported periods. The consolidated financial statements and notes thereto, included herein, should be read in conjunction with the financial statements and notes for the years ended September 30, 2020, 2019 and 2018 that are included in the Company's 2020 Form 10-K. The consolidated financial statements for the year ended September 30, 2021 will be audited by the Company's independent registered public accounting firm after the end of the fiscal year. The earnings for the six months ended March 31, 2021 should not be taken as a prediction of earnings for the entire fiscal year ending September 30, 2021. Most of the business of the Utility segment is seasonal in nature and is influenced by weather conditions. Due to the seasonal nature of the heating business in the Utility segment, earnings during the winter months normally represent a substantial part of the earnings that this business is expected to achieve for the entire fiscal year. The Company’s business segments are discussed more fully in Note 9 – Business Segment Information. Consolidated Statements of Cash Flows. The components, as reported on the Company’s Consolidated Balance Sheets, of the total cash, cash equivalents, and restricted cash presented on the Statement of Cash Flows are as follows (in thousands): Six Months Ended Six Months Ended Balance at October 1, 2020 Balance at Balance at October 1, 2019 Balance at Cash and Temporary Cash Investments $ 20,541 $ 80,467 $ 20,428 $ 111,655 Hedging Collateral Deposits — — 6,832 10,728 Cash, Cash Equivalents, and Restricted Cash $ 20,541 $ 80,467 $ 27,260 $ 122,383 The Company considers all highly liquid debt instruments purchased with a maturity date of generally three months or less to be cash equivalents. The Company’s restricted cash is composed entirely of amounts reported as Hedging Collateral Deposits on the Consolidated Balance Sheets. Hedging Collateral Deposits is an account title for cash held in margin accounts funded by the Company to serve as collateral for hedging positions. In accordance with its accounting policy, the Company does not offset hedging collateral deposits paid or received against related derivative financial instruments liability or asset balances. Allowance for Uncollectible Accounts. The allowance for uncollectible accounts is the Company’s best estimate of the amount of probable credit losses in the existing accounts receivable. The allowance is determined based on historical experience, the age of customer accounts, other specific information about customer accounts, and the economic environment. Account balances are charged off against the allowance twelve months after the account is final billed or when it is anticipated that the receivable will not be recovered. To date, as a result of the COVID-19 pandemic, the Company has started to see modest increases in their receivable balances due to customer non-payments. As a result, the Company has increased the bad debt reserve to account for the higher receivable balances. Activity in the allowance for uncollectible accounts for the six months ended March 31, 2021 are as follows: Balance at Beginning of Period Additions Charged to Costs and Expenses Add: Deduct: Balance at End of Period Six Months Ended March 31, 2021 Allowance for Uncollectible Accounts $ 22,810 $ 11,074 $ 737 $ 4,493 $ 30,128 Gas Stored Underground. In the Utility segment, gas stored underground is carried at lower of cost or net realizable value, on a LIFO method. Gas stored underground normally declines during the first and second quarters of the year and is replenished during the third and fourth quarters. In the Utility segment, the current cost of replacing gas withdrawn from storage is recorded in the Consolidated Statements of Income and a reserve for gas replacement is recorded in the Consolidated Balance Sheets under the caption “Other Accruals and Current Liabilities.” Such reserve, which amounted to $21.4 million at March 31, 2021, is reduced to zero by September 30 of each year as the inventory is replenished. Materials, Supplies and Emission Allowances. The components of the Company's materials, supplies and emission allowances are as follows: At March 31, 2021 At September 30, 2020 Materials and Supplies - at average cost $ 33,532 $ 33,859 Emission Allowances 18,680 18,018 $ 52,212 $ 51,877 Property, Plant and Equipment. In the Company’s Exploration and Production segment, oil and gas property acquisition, exploration and development costs are capitalized under the full cost method of accounting. Under this methodology, all costs associated with property acquisition, exploration and development activities are capitalized, including internal costs directly identified with acquisition, exploration and development activities. The internal costs that are capitalized do not include any costs related to production, general corporate overhead, or similar activities. The Company does not recognize any gain or loss on the sale or other disposition of oil and gas properties unless the gain or loss would significantly alter the relationship between capitalized costs and proved reserves of oil and gas attributable to a cost center. The Company's capitalized costs relating to oil and gas producing activities, net of accumulated depreciation, depletion and amortization, were $1.8 billion at both March 31, 2021 and September 30, 2020. Capitalized costs include costs related to unproved properties, which are excluded from amortization until proved reserves are found or it is determined that the unproved properties are impaired. Such costs amounted to $149.2 million and $148.1 million at March 31, 2021 and September 30, 2020, respectively. All costs related to unproved properties are reviewed quarterly to determine if impairment has occurred. The amount of any impairment is transferred to the pool of capitalized costs being amortized. Capitalized costs are subject to the SEC full cost ceiling test. The ceiling test, which is performed each quarter, determines a limit, or ceiling, on the amount of property acquisition, exploration and development costs that can be capitalized. The ceiling under this test represents (a) the present value of estimated future net cash flows, excluding future cash outflows associated with settling asset retirement obligations that have been accrued on the balance sheet, using a discount factor of 10%, which is computed by applying prices of oil and gas (as adjusted for hedging) to estimated future production of proved oil and gas reserves as of the date of the latest balance sheet, less estimated future expenditures, plus (b) the cost of unevaluated properties not being depleted, less (c) income tax effects related to the differences between the book and tax basis of the properties. The gas and oil prices used to calculate the full cost ceiling are based on an unweighted arithmetic average of the first day of the month oil and gas prices for each month within the twelve-month period prior to the end of the reporting period. If capitalized costs, net of accumulated depreciation, depletion and amortization and related deferred income taxes, exceed the ceiling at the end of any quarter, a permanent non-cash impairment is required to be charged to earnings in that quarter. At March 31, 2021, the ceiling exceeded the book value of the oil and gas properties by approximately $145.4 million. The book value of the oil and gas properties exceeded the ceiling at December 31, 2020. As such, the Company recognized a non-cash, pre-tax impairment charge of $76.2 million for the quarter ended December 31, 2020. A deferred income tax benefit of $21.0 million related to the non-cash impairment charge was also recognized for the quarter ended December 31, 2020. In adjusting estimated future cash flows for hedging under the ceiling test at March 31, 2021, estimated future net cash flows were increased by $127.9 million. The principal assets of the Utility, Pipeline and Storage and Gathering segments, consisting primarily of gas distribution pipelines, transmission pipelines, storage facilities, gathering lines and compressor stations, are recorded at historical cost. Despite the economic conditions arising from the COVID-19 pandemic, there were no indications of any impairments to property, plant and equipment in the Utility, Pipeline and Storage and Gathering segments at March 31, 2021. Management will continue to monitor the situation on a quarterly basis. Accumulated Other Comprehensive Income (Loss). The components of Accumulated Other Comprehensive Income (Loss) and changes for the six months ended March 31, 2021 and 2020, net of related tax effect, are as follows (amounts in parentheses indicate debits) (in thousands): Gains and Losses on Derivative Financial Instruments Funded Status of the Pension and Other Post-Retirement Benefit Plans Total Three Months Ended March 31, 2021 Balance at January 1, 2021 $ 10,151 $ (89,892) $ (79,741) Other Comprehensive Gains and Losses Before Reclassifications (24,903) — (24,903) Amounts Reclassified From Other Comprehensive Income (Loss) 2,656 — 2,656 Balance at March 31, 2021 $ (12,096) $ (89,892) $ (101,988) Six Months Ended March 31, 2021 Balance at October 1, 2020 $ (24,865) $ (89,892) $ (114,757) Other Comprehensive Gains and Losses Before Reclassifications 9,888 — 9,888 Amounts Reclassified From Other Comprehensive Income (Loss) 2,881 — 2,881 Balance at March 31, 2021 $ (12,096) $ (89,892) $ (101,988) Three Months Ended March 31, 2020 Balance at January 1, 2020 $ 30,680 $ (86,830) $ (56,150) Other Comprehensive Gains and Losses Before Reclassifications 55,450 — 55,450 Amounts Reclassified From Other Comprehensive Income (Loss) (18,217) — (18,217) Balance at March 31, 2020 $ 67,913 $ (86,830) $ (18,917) Six Months Ended March 31, 2020 Balance at October 1, 2019 $ 34,675 $ (86,830) $ (52,155) Other Comprehensive Gains and Losses Before Reclassifications 55,825 — 55,825 Amounts Reclassified From Other Comprehensive Income (Loss) (23,537) — (23,537) Cumulative Effect of Adoption of Authoritative Guidance for Hedging 950 — 950 Balance at March 31, 2020 $ 67,913 $ (86,830) $ (18,917) In August 2017, the FASB issued authoritative guidance which changed the financial reporting of hedging relationships to better portray the economic results of an entity's risk management activities and to simplify the application of hedge accounting. The Company adopted this authoritative guidance effective October 1, 2019, recognizing a cumulative effect adjustment that decreased retained earnings by $1.0 million and increased accumulated other comprehensive income by the same amount. Reclassifications Out of Accumulated Other Comprehensive Income (Loss). The details about the reclassification adjustments out of accumulated other comprehensive income (loss) for the six months ended March 31, 2021 and 2020 are as follows (amounts in parentheses indicate debits to the income statement) (in thousands): Details About Accumulated Other Comprehensive Income (Loss) Components Amount of Gain or (Loss) Reclassified from Accumulated Other Comprehensive Affected Line Item in the Statement Where Net Income is Presented Three Months Ended Six Months Ended March 31, 2021 2020 2021 2020 Gains (Losses) on Derivative Financial Instrument Cash Flow Hedges: Commodity Contracts ($3,761) $23,396 ($4,071) $30,937 Operating Revenues Commodity Contracts — 1,909 — 1,911 Purchased Gas Foreign Currency Contracts 95 (271) 94 (462) Operating Revenues (3,666) 25,034 (3,977) 32,386 Total Before Income Tax 1,010 (6,817) 1,096 (8,849) Income Tax Expense ($2,656) $18,217 ($2,881) $23,537 Net of Tax Other Current Assets . The components of the Company’s Other Current Assets are as follows (in thousands): At March 31, 2021 At September 30, 2020 Prepayments $ 7,692 $ 12,851 Prepaid Property and Other Taxes 23,373 14,269 State Income Taxes Receivable — 3,828 Regulatory Assets 25,052 16,609 $ 56,117 $ 47,557 Other Accruals and Current Liabilities . The components of the Company’s Other Accruals and Current Liabilities are as follows (in thousands): At March 31, 2021 At September 30, 2020 Accrued Capital Expenditures $ 49,526 $ 33,344 Regulatory Liabilities 34,832 44,890 Reserve for Gas Replacement 21,432 — Liability for Royalty and Working Interests 22,475 15,665 Non-Qualified Benefit Plan Liability 14,460 14,460 Other 34,215 31,817 $ 176,940 $ 140,176 Earnings Per Common Share. Basic earnings per common share is computed by dividing income or loss by the weighted average number of common shares outstanding for the period. Diluted earnings per common share reflects the potential dilution that could occur if securities or other contracts to issue common stock were exercised or converted into common stock. For purposes of determining earnings per common share, the potentially dilutive securities the Company had outstanding were SARs, restricted stock units and performance shares. For the quarter and six months ended March 31, 2021, the diluted weighted average shares outstanding shown on the Consolidated Statements of Income reflects the potential dilution as a result of these securities as determined using the Treasury Stock Method. SARs, restricted stock units and performance shares that are antidilutive are excluded from the calculation of diluted earnings per common share. There were 334,945 securities excluded as being antidilutive for both the quarter and six months ended March 31, 2021. As the Company recognized a net loss for both the quarter and six months ended March 31, 2020, the aforementioned potentially dilutive securities, amounting to 310,015 and 406,748 securities, were not recognized in the diluted earnings per share calculation for the quarter and six months ended March 31, 2020, respectively. Stock-Based Compensation. The Company granted 309,470 performance shares during the six months ended March 31, 2021. The weighted average fair value of such performance shares was $39.19 per share for the six months ended March 31, 2021. Performance shares are an award constituting units denominated in common stock of the Company, the number of which may be adjusted over a performance cycle based upon the extent to which performance goals have been satisfied. Earned performance shares may be distributed in the form of shares of common stock of the Company, an equivalent value in cash or a combination of cash and shares of common stock of the Company, as determined by the Company. The performance shares do not entitle the participant to receive dividends during the vesting period. Half of the performance shares granted during the six months ended March 31, 2021 must meet a performance goal related to relative return on capital over a three-year performance cycle. The performance goal over the performance cycle is the Company’s total return on capital relative to the total return on capital of other companies in a group selected by the Compensation Committee (“Report Group”). Total return on capital for a given company means the average of the Report Group companies’ returns on capital for each twelve month period corresponding to each of the Company’s fiscal years during the performance cycle, based on data reported for the Report Group companies in the Bloomberg database. The number of these performance shares that will vest and be paid will depend upon the Company’s performance relative to the Report Group and not upon the absolute level of return achieved by the Company. The fair value of these performance shares is calculated by multiplying the expected number of shares that will be issued by the average market price of Company common stock on the date of grant reduced by the present value of forgone dividends over the vesting term of the award. The fair value is recorded as compensation expense over the vesting term of the award. The other half of the performance shares granted during the six months ended March 31, 2021 must meet a performance goal related to relative total shareholder return over a three-year performance cycle. The performance goal over the performance cycle is the Company’s three-year total shareholder return relative to the three-year total shareholder return of the other companies in the Report Group. Three-year total shareholder return for a given company will be based on the data reported for that company (with the starting and ending stock prices over the performance cycle calculated as the average closing stock price for the prior calendar month and with dividends reinvested in that company’s securities at each ex-dividend date) in the Bloomberg database. The number of these total shareholder return performance shares ("TSR performance shares") that will vest and be paid will depend upon the Company’s performance relative to the Report Group and not upon the absolute level of return achieved by the Company. The fair value price at the date of grant for the TSR performance shares is determined using a Monte Carlo simulation technique, which includes a reduction in value for the present value of forgone dividends over the vesting term of the award. This price is multiplied by the number of TSR performance shares awarded, the result of which is recorded as compensation expense over the vesting term of the award. The Company granted 172,513 restricted stock units during the six months ended March 31, 2021. The weighted average fair value of such restricted stock units was $37.98 per share for the six months ended March 31, 2021. Restricted stock units represent the right to receive shares of common stock of the Company (or the equivalent value in cash or a combination of cash and shares of common stock of the Company, as determined by the Company) at the end of a specified time period. These restricted stock units do not entitle the participant to receive dividends during the vesting period. The accounting for restricted stock units is the same as the accounting for restricted share awards, except that the fair value at the date of grant of the restricted stock units must be reduced by the present value of forgone dividends over the vesting term of the award.

Asset Acquisitions and Divestit

Asset Acquisitions and Divestitures	6 Months Ended
	Mar. 31, 2021
Business Combinations [Abstract]
Asset Acquisitions and Divestitures	Asset Acquisitions and Divestitures     On December 10, 2020, the Company completed the sale of substantially all timber properties in Pennsylvania to Lyme Emporium Highlands III LLC and Lyme Allegheny Land Company II LLC for net proceeds of $104.6 million. At September 30, 2020, these assets, amounting to $53.4 million, which previously were recorded as Net Property, Plant and Equipment, were presented as Assets Held for Sale, Net on the Consolidated Balance Sheet. The assets were a component of the Company’s All Other category and did not have a major impact on the Company’s operations or financial results. After purchase price adjustments and transaction costs, a gain of $51.1 million was recognized on the sale of these assets. Since the sale did not represent a strategic shift in focus for the Company, the financial results associated with operating these assets as well as the gain on sale have not been reported as discontinued operations.    The sale of the timber properties completed a reverse like-kind exchange pursuant to Section 1031 of the Internal Revenue Code, as amended (“Reverse 1031 Exchange”). On July 31, 2020, the Company completed its acquisition of certain upstream assets and midstream gathering assets in Pennsylvania from SWEPI LP, a subsidiary of Royal Dutch Shell plc (“Shell”) for total consideration of $506.3 million. The purchase and sale agreement with Shell was structured, in part, as a Reverse 1031 Exchange. In connection with the Reverse 1031 Exchange, the Company, through a subsidiary, assigned the rights to acquire legal title to certain oil and natural gas properties to a Variable Interest Entity ("VIE") formed by an exchange accommodation titleholder. From July 31, 2020 to December 10, 2020, a subsidiary of the Company operated the properties pursuant to a lease agreement with the VIE. As the Company was deemed to be the primary beneficiary of the VIE, the VIE was included in the consolidated financial statements of the Company. Upon completion of the sale of the timber properties on December 10, 2020, the affected properties were conveyed to the Company and the VIE structure was terminated. Refer to Note B – Asset Acquisitions and Divestitures of the Company’s 2020 Form 10-K for additional information concerning the Company’s acquisition of certain upstream assets and midstream gathering assets from Shell.

Revenue from Contracts with Cus

Revenue from Contracts with Customers	6 Months Ended
	Mar. 31, 2021
Revenue from Contract with Customer [Abstract]
Revenue from Contracts with Customers	Revenue from Contracts with Customers The following tables provide a disaggregation of the Company's revenues for the quarter and six months ended March 31, 2021 and 2020, presented by type of service from each reportable segment. Quarter Ended March 31, 2021 (Thousands) Revenues By Type of Service Exploration and Production Pipeline and Storage Gathering Utility All Other Corporate and Intersegment Eliminations Total Consolidated Production of Natural Gas $ 188,769 $ — $ — $ — $ — $ — $ 188,769 Production of Crude Oil 33,589 — — — — — 33,589 Natural Gas Processing 772 — — — — — 772 Natural Gas Gathering Service — — 50,262 — — (49,591) 671 Natural Gas Transportation Service — 64,648 — 39,514 — (18,187) 85,975 Natural Gas Storage Service — 21,231 — — — (9,108) 12,123 Natural Gas Residential Sales — — — 203,768 — — 203,768 Natural Gas Commercial Sales — — — 28,872 — — 28,872 Natural Gas Industrial Sales — — — 1,368 — — 1,368 Natural Gas Marketing — — — — 66 (1) 65 Other 818 825 — (4,519) (1) (97) (2,974) Total Revenues from Contracts with Customers 223,948 86,704 50,262 269,003 65 (76,984) 552,998 Alternative Revenue Programs — — — 1,878 — — 1,878 Derivative Financial Instruments (3,761) — — — — — (3,761) Total Revenues $ 220,187 $ 86,704 $ 50,262 $ 270,881 $ 65 $ (76,984) $ 551,115 Six Months Ended March 31, 2021 (Thousands) Revenues By Type of Service Exploration and Production Pipeline and Storage Gathering Utility All Other Corporate and Intersegment Eliminations Total Consolidated Production of Natural Gas $ 355,212 $ — $ — $ — $ — $ — $ 355,212 Production of Crude Oil 58,088 — — — — — 58,088 Natural Gas Processing 1,324 — — — — — 1,324 Natural Gas Gathering Service — — 97,270 — — (96,249) 1,021 Natural Gas Transportation Service — 129,473 — 68,535 — (37,777) 160,231 Natural Gas Storage Service — 41,748 — — — (17,871) 23,877 Natural Gas Residential Sales — — — 341,649 — — 341,649 Natural Gas Commercial Sales — — — 46,067 — — 46,067 Natural Gas Industrial Sales — — — 2,290 — — 2,290 Natural Gas Marketing — — — — 650 (20) 630 Other 1,029 3,248 — (6,131) 545 (205) (1,514) Total Revenues from Contracts with Customers 415,653 174,469 97,270 452,410 1,195 (152,122) 988,875 Alternative Revenue Programs — — — 7,471 — — 7,471 Derivative Financial Instruments (4,071) — — — — — (4,071) Total Revenues $ 411,582 $ 174,469 $ 97,270 $ 459,881 $ 1,195 $ (152,122) $ 992,275 Quarter Ended March 31, 2020 (Thousands) Revenues By Type of Service Exploration and Production Pipeline and Storage Gathering Utility All Other Corporate and Intersegment Eliminations Total Consolidated Production of Natural Gas $ 100,777 $ — $ — $ — $ — $ — $ 100,777 Production of Crude Oil 30,268 — — — — — 30,268 Natural Gas Processing 714 — — — — — 714 Natural Gas Gathering Service — — 35,267 — — (35,267) — Natural Gas Transportation Service — 58,454 — 39,832 — (21,976) 76,310 Natural Gas Storage Service — 20,524 — — — (9,087) 11,437 Natural Gas Residential Sales — — — 185,323 — — 185,323 Natural Gas Commercial Sales — — — 27,296 — — 27,296 Natural Gas Industrial Sales — — — 1,144 — — 1,144 Natural Gas Marketing — — — — 36,404 (79) 36,325 Other 405 267 — (3,524) 851 (65) (2,066) Total Revenues from Contracts with Customers 132,164 79,245 35,267 250,071 37,255 (66,474) 467,528 Alternative Revenue Programs — — — 4,422 — — 4,422 Derivative Financial Instruments 23,396 — — — (4,251) — 19,145 Total Revenues $ 155,560 $ 79,245 $ 35,267 $ 254,493 $ 33,004 $ (66,474) $ 491,095 Six Months Ended March 31, 2020 (Thousands) Revenues By Type of Service Exploration and Production Pipeline and Storage Gathering Utility All Other Corporate and Intersegment Eliminations Total Consolidated Production of Natural Gas $ 220,651 $ — $ — $ — $ — $ — $ 220,651 Production of Crude Oil 67,931 — — — — — 67,931 Natural Gas Processing 1,402 — — — — — 1,402 Natural Gas Gathering Service — — 70,055 — — (70,055) — Natural Gas Transportation Service — 111,906 — 72,640 — (38,963) 145,583 Natural Gas Storage Service — 38,950 — — — (17,079) 21,871 Natural Gas Residential Sales — — — 329,693 — — 329,693 Natural Gas Commercial Sales — — — 46,137 — — 46,137 Natural Gas Industrial Sales — — — 2,413 — — 2,413 Natural Gas Marketing — — — — 70,513 (256) 70,257 Other 578 609 — (6,848) 1,971 (118) (3,808) Total Revenues from Contracts with Customers 290,562 151,465 70,055 444,035 72,484 (126,471) 902,130 Alternative Revenue Programs — — — 7,283 — — 7,283 Derivative Financial Instruments 30,937 — — — (5,067) — 25,870 Total Revenues $ 321,499 $ 151,465 $ 70,055 $ 451,318 $ 67,417 $ (126,471) $ 935,283 The Company records revenue related to its derivative financial instruments in the Exploration and Production segment as well as in its NFR operations (included in the All Other category). The Company discontinued use of derivative financial instruments in its NFR operations upon completing the sale of its commercial and industrial contracts and certain other assets on August 1, 2020. The Company has been winding down its NFR operations since August 1, 2020 which has resulted in a significant reduction in natural gas marketing revenues as shown in the tables above. The Company also records revenue related to alternative revenue programs in its Utility segment. Revenue related to derivative financial instruments and alternative revenue programs are excluded from the scope of the authoritative guidance regarding revenue recognition since they are accounted for under other existing accounting guidance. The Company’s Pipeline and Storage segment expects to recognize the following revenue amounts in future periods related to “fixed” charges associated with remaining performance obligations for transportation and storage contracts: $94.6 million for the remainder of fiscal 2021; $179.7 million for fiscal 2022; $144.5 million for fiscal 2023; $124.3 million for fiscal 2024; $117.0 million for fiscal 2025; and $517.5 million thereafter.

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Mar. 31, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The FASB authoritative guidance regarding fair value measurements establishes a fair-value hierarchy and prioritizes the inputs used in valuation techniques that measure fair value. Those inputs are prioritized into three levels. Level 1 inputs are unadjusted quoted prices in active markets for assets or liabilities that the Company can access at the measurement date. Level 2 inputs are inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly at the measurement date. Level 3 inputs are unobservable inputs for the asset or liability at the measurement date. The Company’s assessment of the significance of a particular input to the fair value measurement requires judgment, and may affect the valuation of fair value assets and liabilities and their placement within the fair value hierarchy levels. The following table sets forth, by level within the fair value hierarchy, the Company's financial assets and liabilities (as applicable) that were accounted for at fair value on a recurring basis as of March 31, 2021 and September 30, 2020. Financial assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. The fair value presentation for over-the-counter swaps combines gas and oil swaps because a significant number of the counterparties enter into both gas and oil swap agreements with the Company. Recurring Fair Value Measures At fair value as of March 31, 2021 (Thousands of Dollars) Level 1 Level 2 Level 3 Netting Adjustments (1) Total (1) Assets: Cash Equivalents – Money Market Mutual Funds $ 66,759 $ — $ — $ — $ 66,759 Derivative Financial Instruments: Over the Counter Swaps – Gas and Oil — 18,805 — (14,768) 4,037 Over the Counter No Cost Collars – Gas — — — (118) (118) Foreign Currency Contracts — 1,437 — (1,252) 185 Other Investments: Balanced Equity Mutual Fund 32,993 — — — 32,993 Fixed Income Mutual Fund 70,133 — — — 70,133 Common Stock – Financial Services Industry 988 — — — 988 Total $ 170,873 $ 20,242 $ — $ (16,138) $ 174,977 Liabilities: Derivative Financial Instruments: Over the Counter Swaps – Gas and Oil — 35,809 — (14,768) 21,041 Over the Counter No Cost Collars – Gas — 1,488 — (118) 1,370 Foreign Currency Contracts — 72 — (1,252) (1,180) Total $ — $ 37,369 $ — $ (16,138) $ 21,231 Total Net Assets/(Liabilities) $ 170,873 $ (17,127) $ — $ — $ 153,746 Recurring Fair Value Measures At fair value as of September 30, 2020 (Thousands of Dollars) Level 1 Level 2 Level 3 Netting Adjustments (1) Total (1) Assets: Cash Equivalents – Money Market Mutual Funds $ 12,285 $ — $ — $ — $ 12,285 Derivative Financial Instruments: Over the Counter Swaps – Gas and Oil — 36,418 — (26,400) 10,018 Over the Counter No Cost Collars – Gas — — — (720) (720) Foreign Currency Contracts — 259 — (338) (79) Other Investments: Balanced Equity Mutual Fund 39,618 — — — 39,618 Fixed Income Mutual Fund 72,253 — — — 72,253 Common Stock – Financial Services Industry 639 — — — 639 Total $ 124,795 $ 36,677 $ — $ (27,458) $ 134,014 Liabilities: Derivative Financial Instruments: Over the Counter Swaps – Gas and Oil — 61,280 — (26,400) 34,880 Over the Counter No Cost Collars – Gas — 8,171 — (720) 7,451 Foreign Currency Contracts — 1,976 — (338) 1,638 Total $ — $ 71,427 $ — $ (27,458) $ 43,969 Total Net Assets/(Liabilities) $ 124,795 $ (34,750) $ — $ — $ 90,045 (1) Netting Adjustments represent the impact of legally-enforceable master netting arrangements that allow the Company to net gain and loss positions held with the same counterparties. The net asset or net liability for each counterparty is recorded as an asset or liability on the Company’s balance sheet. Derivative Financial Instruments The derivative financial instruments reported in Level 2 at March 31, 2021 and September 30, 2020 consist of natural gas price swap agreements, natural gas no cost collars, crude oil price swap agreements, and foreign currency contracts, all of which are used in the Company’s Exploration and Production segment. The fair value of the Level 2 price swap agreements and no cost collars is based on an internal, discounted cash flow model that uses observable inputs (i.e. LIBOR based discount rates and basis differential information, if applicable, at active natural gas and crude oil trading markets). The fair value of the Level 2 foreign currency contracts is determined using the market approach based on observable market transactions of forward Canadian currency rates. The authoritative guidance for fair value measurements and disclosures require consideration of the impact of nonperformance risk (including credit risk) from a market participant perspective in the measurement of the fair value of assets and liabilities. At March 31, 2021, the Company determined that nonperformance risk would have no material impact on its financial position or results of operation. To assess nonperformance risk, the Company considered information such as any applicable collateral posted, master netting arrangements, and applied a market-based method by using the counterparty's (assuming the derivative is in a gain position) or the Company’s (assuming the derivative is in a loss position) credit default swaps rates.

Financial Instruments

Financial Instruments	6 Months Ended
	Mar. 31, 2021
Financial Instruments, Owned, at Fair Value [Abstract]
Financial Instruments	Financial Instruments Long-Term Debt. The fair market value of the Company’s debt, as presented in the table below, was determined using a discounted cash flow model, which incorporates the Company’s credit ratings and current market conditions in determining the yield, and subsequently, the fair market value of the debt. Based on these criteria, the fair market value of long-term debt, including current portion, was as follows (in thousands): March 31, 2021 September 30, 2020 Carrying Fair Value Carrying Fair Value Long-Term Debt $ 2,627,033 $ 2,869,081 $ 2,629,576 $ 2,778,556 The fair value amounts are not intended to reflect principal amounts that the Company will ultimately be required to pay. Carrying amounts for other financial instruments recorded on the Company’s Consolidated Balance Sheets approximate fair value. The fair value of long-term debt was calculated using observable inputs (U.S. Treasuries/LIBOR for the risk free component and company specific credit spread information – generally obtained from recent trade activity in the debt). As such, the Company considers the debt to be Level 2. Any temporary cash investments, notes payable to banks and commercial paper are stated at cost. Temporary cash investments are considered Level 1, while notes payable to banks and commercial paper are considered to be Level 2. Given the short-term nature of the notes payable to banks and commercial paper, the Company believes cost is a reasonable approximation of fair value. Other Investments. The components of the Company's Other Investments are as follows (in thousands): At March 31, 2021 At September 30, 2020 Life Insurance Contracts $ 43,307 $ 41,992 Equity Mutual Fund 32,993 39,618 Fixed Income Mutual Fund 70,133 72,253 Marketable Equity Securities 988 639 $ 147,421 $ 154,502 Investments in life insurance contracts are stated at their cash surrender values or net present value. Investments in an equity mutual fund, a fixed income mutual fund and the stock of an insurance company (marketable equity securities) are stated at fair value based on quoted market prices with changes in fair value recognized in net income. The insurance contracts and marketable equity and fixed income securities are primarily informal funding mechanisms for various benefit obligations the Company has to certain employees. Derivative Financial Instruments. The Company uses derivative financial instruments to manage commodity price risk in the Exploration and Production segment. The Company enters into over-the-counter no cost collars and over-the-counter swap agreements for natural gas and crude oil to manage the price risk associated with forecasted sales of gas and oil. In addition, the Company also enters into foreign exchange forward contracts to manage the risk of currency fluctuations associated with transportation costs denominated in Canadian currency in the Exploration and Production segment. These instruments are accounted for as cash flow hedges. The duration of the Company’s cash flow hedges does not typically exceed 5 years while the foreign currency forward contracts do not exceed 10 years. The Company has presented its net derivative assets and liabilities as “Fair Value of Derivative Financial Instruments” on its Consolidated Balance Sheets at March 31, 2021 and September 30, 2020. Substantially all of the derivative financial instruments reported on those line items relate to commodity contracts and a small portion relates to foreign currency forward contracts. Cash Flow Hedges For derivative instruments that are designated and qualify as a cash flow hedge, the gain or loss on the derivative is reported as a component of other comprehensive income (loss) and reclassified into earnings in the period or periods during which the hedged transaction affects earnings. As of March 31, 2021, the Company had the following commodity derivative contracts (swaps and no cost collars) outstanding: Commodity Units Natural Gas 253.3 Bcf Crude Oil 2,082,000 Bbls As of March 31, 2021, the Company was hedging a total of $69.4 million of forecasted transportation costs denominated in Canadian dollars with foreign currency forward contracts. As of March 31, 2021, the Company had $17.1 million ($12.1 million after-tax) of net hedging losses included in the accumulated other comprehensive income (loss) balance. It is expected that $28.2 million ($19.9 million after-tax) of unrealized losses will be reclassified into the Consolidated Statement of Income within the next 12 months as the underlying hedged transactions are recorded in earnings. The Effect of Derivative Financial Instruments on the Statement of Financial Performance for the Three Months Ended March 31, 2021 and 2020 (Thousands of Dollars) Derivatives in Cash Flow Hedging Relationships Amount of Derivative Gain or (Loss) Recognized in Other Comprehensive Income (Loss) on Location of Derivative Gain or (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) on the Consolidated Balance Sheet into the Consolidated Statement of Income Amount of Derivative Gain or (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) on the Consolidated Balance Sheet into the Consolidated Statement of Income for the 2021 2020 2021 2020 Commodity Contracts $ (35,123) $ 81,108 Operating Revenue $ (3,761) $ 23,396 Commodity Contracts — (134) Purchased Gas — 1,909 Foreign Currency Contracts 750 (4,670) Operating Revenue 95 (271) Total $ (34,373) $ 76,304 $ (3,666) $ 25,034 The Effect of Derivative Financial Instruments on the Statement of Financial Performance for the Six Months Ended March 31, 2021 and 2020 (Thousands of Dollars) Derivatives in Cash Flow Hedging Relationships Amount of Derivative Gain or Location of Derivative Gain or (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) on the Consolidated Balance Sheet into the Consolidated Statement of Income Amount of Derivative Gain or 2021 2020 2021 2020 Commodity Contracts $ 10,472 $ 79,553 Operating Revenue $ (4,071) $ 30,937 Commodity Contracts — 997 Purchased Gas — 1,911 Foreign Currency Contracts 3,176 (3,751) Operating Revenue 94 (462) Total $ 13,648 $ 76,799 $ (3,977) $ 32,386 Credit Risk The Company may be exposed to credit risk on any of the derivative financial instruments that are in a gain position. Credit risk relates to the risk of loss that the Company would incur as a result of nonperformance by counterparties pursuant to the terms of their contractual obligations. To mitigate such credit risk, management performs a credit check, and then on a quarterly basis monitors counterparty credit exposure. The majority of the Company’s counterparties are financial institutions and energy traders. The Company has over-the-counter swap positions, no cost collars and applicable foreign currency forward contracts with fifteen counterparties of which five are in a net gain position. On average, the Company had $0.8 million of credit exposure per counterparty in a gain position at March 31, 2021. The maximum credit exposure per counterparty in a gain position at March 31, 2021 was $1.6 million. As of March 31, 2021, no collateral was received from the counterparties by the Company. The Company's gain position on such derivative financial instruments had not exceeded the established thresholds at which the counterparties would be required to post collateral, nor had the counterparties' credit ratings declined to levels at which the counterparties were required to post collateral. As of March 31, 2021, thirteen of the fifteen counterparties to the Company’s outstanding derivative instrument contracts (specifically the over-the-counter swaps, over-the-counter no cost collars and applicable foreign currency forward contracts) had a common credit-risk related contingency feature. In the event the Company’s credit rating increases or falls below a certain threshold (applicable debt ratings), the available credit extended to the Company would either increase or decrease. A decline in the Company’s credit rating, in and of itself, would not cause the Company to be required to increase the level of its hedging collateral deposits (in the form of cash deposits, letters of credit or treasury debt instruments). If the Company’s outstanding derivative instrument contracts were in a liability position (or if the liability were larger) and/or the Company’s credit rating declined, then additional hedging collateral deposits may be required. At March 31, 2021, the fair market value of the derivative financial instrument assets with a credit-risk related contingency feature was $1.5 million according to the Company’s internal model (discussed in Note 4 – Fair Value Measurements). At March 31, 2021, the fair market value of the derivative financial instrument liabilities with a credit-risk related contingency feature was $21.2 million according to the Company's internal model. For its over-the-counter swap agreements and foreign currency forward contracts, no hedging collateral deposits were required to be posted by the Company at March 31, 2021.

Income Taxes

Income Taxes	6 Months Ended
	Mar. 31, 2021
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The effective tax rates for the quarters ended March 31, 2021 and March 31, 2020 were 26.3% and negative 53.2%, respectively. The effective tax rates for the six months ended March 31, 2021 and March 31, 2020 were 26.8% and 139.9%, respectively. The change in the tax rate is primarily the result of a valuation allowance initially established in the quarter ended March 31, 2020, discussed below. A valuation allowance for deferred tax assets, including net operating losses and tax credits, is recognized when it is more likely than not that some or all of the benefit from the deferred tax assets will not be realized. The Company continually assesses the realizability of its deferred tax assets, including factors such as future taxable income, reversal of existing temporary differences, and tax planning strategies. The Company considers both positive and negative evidence related to the likelihood of the realization of the deferred tax assets. As of March 31, 2020, the Company recorded a valuation allowance against certain state deferred tax assets in the amount of $56.8 million based on its conclusion, considering all available objective evidence and the Company’s history of subsidiary state tax losses, that it was more likely than not that the deferred tax assets would not be realized. The valuation allowance increased to $63.9 million as of March 31, 2021 as a result of certain state net operating loss and tax credit activity. Changes in judgment regarding future realization of these deferred tax assets may result in a reversal of all or a portion of the valuation allowance. The Company will continue to re-assess this position each quarter. On March 27, 2020, the “Coronavirus Aid, Relief and Economic Security (CARES) Act” was signed into law. The CARES Act, among other things, includes provisions relating to alternative minimum tax (AMT) credit refunds, refundable payroll tax credits, deferment of employer side social security payments, net operating loss carryback periods, and modifications to the net interest deduction limitation. The 2017 Tax Reform Act had repealed the corporate AMT and provided that the Company’s existing AMT credit carryovers were refundable over a four year period. As of September 30, 2018, the Company had $85.0 million of AMT credit carryovers. The Company received the first installment for $42.5 million of AMT credit refunds related to fiscal 2019 in January 2020 and filed for the acceleration of the remaining AMT credit refunds of $42.5 million, which were received in June 2020. On December 27, 2020, the “Consolidated Appropriations Act, 2021 (CAA)” was signed into law. The CAA clarifies and expands the Paycheck Protection Program loans and the Employee Retention Credit as well as several other tax provisions first outlined in the CARES Act. The CAA is currently being evaluated, however, the Company does not anticipate a material impact as a result of this legislation. On March 11, 2021, the “American Rescue Plan Act of 2021” was signed into law. The Company is still evaluating the impacts of this legislation but does not anticipate a material impact as a result of this legislation.

Capitalization

Capitalization	3 Months Ended
	Mar. 31, 2021
Capitalization, Long-term Debt and Equity [Abstract]
Capitalization	Capitalization Summary of Changes in Common Stock Equity Common Stock Paid In Earnings Accumulated Shares Amount (Thousands, except per share amounts) Balance at January 1, 2021 91,153 $ 91,153 $ 1,004,369 $ 1,028,844 $ (79,741) Net Income Available for Common Stock 112,436 Dividends Declared on Common Stock ($0.445 Per Share) (40,562) Other Comprehensive Loss, Net of Tax (22,247) Share-Based Payment Expense (1) 4,283 Common Stock Issued Under Stock and Benefit Plans 11 11 423 Balance at March 31, 2021 91,164 $ 91,164 $ 1,009,075 $ 1,100,718 $ (101,988) Balance at October 1, 2020 90,955 $ 90,955 $ 1,004,158 $ 991,630 $ (114,757) Net Income Available for Common Stock 190,210 Dividends Declared on Common Stock ($0.89 Per Share) (81,122) Other Comprehensive Income, Net of Tax 12,769 Share-Based Payment Expense (1) 7,779 Common Stock Issued (Repurchased) Under Stock and Benefit Plans 209 209 (2,862) Balance at March 31, 2021 91,164 $ 91,164 $ 1,009,075 $ 1,100,718 $ (101,988) Balance at January 1, 2020 86,552 $ 86,552 $ 831,146 $ 1,320,592 $ (56,150) Net Income (Loss) Available for Common Stock (106,068) Dividends Declared on Common Stock ($0.435 Per Share) (37,654) Other Comprehensive Income, Net of Tax 37,233 Share-Based Payment Expense (1) 3,876 Common Stock Issued Under Stock and Benefit Plans 10 10 422 Balance at March 31, 2020 86,562 $ 86,562 $ 835,444 $ 1,176,870 $ (18,917) Balance at October 1, 2019 86,315 $ 86,315 $ 832,264 $ 1,272,601 $ (52,155) Net Income (Loss) Available for Common Stock (19,477) Dividends Declared on Common Stock ($0.87 Per Share) (75,304) Cumulative Effect of Adoption of Authoritative Guidance for Hedging (950) Other Comprehensive Income, Net of Tax 33,238 Share-Based Payment Expense (1) 6,704 Common Stock Issued (Repurchased) Under Stock and Benefit Plans 247 247 (3,524) Balance at March 31, 2020 86,562 $ 86,562 $ 835,444 $ 1,176,870 $ (18,917) (1) Paid in Capital includes compensation costs associated with performance shares and/or restricted stock awards. The expense is included within Net Income Available For Common Stock, net of tax benefits. Common Stock. During the six months ended March 31, 2021, the Company issued 105,260 original issue shares of common stock for restricted stock units that vested and 165,161 original issue shares of common stock for performance shares that vested. The Company also issued 21,616 original issue shares of common stock to the non-employee directors of the Company who receive compensation under the Company’s 2009 Non-Employee Director Equity Compensation Plan, including the reinvestment of dividends for certain non-employee directors who elected to defer their shares pursuant to the dividend reinvestment feature of the Company's Non-Employee Directors Deferred Compensation Plan during the six months ended March 31, 2021. Holders of stock-based compensation awards will often tender shares of common stock to the Company for payment of applicable withholding taxes. During the six months ended March 31, 2021, 82,936 shares of common stock were tendered to the Company for such purposes. The Company considers all shares tendered as cancelled shares restored to the status of authorized but unissued shares, in accordance with New Jersey law. Current Portion of Long-Term Debt. None of the Company's long-term debt as of March 31, 2021 and September 30, 2020 had a maturity date within the following twelve-month period. Long-Term Debt. On February 24, 2021, the Company issued $500.0 million of 2.95% notes due March 1, 2031. After deducting underwriting discounts, commissions and other debt issuance costs, the net proceeds to the Company amounted to $495.3 million. The holders of the notes may require the Company to repurchase their notes at a price equal to 101% of the principal amount in the event of both a change in control and a ratings downgrade to a rating below investment grade. Additionally, the interest rate payable on the notes will be subject to adjustment from time to time, with a maximum adjustment of 2.00%, if certain change of control events involving a material subsidiary result in a downgrade of the credit rating assigned to the notes below investment grade (or if the credit rating assigned to the notes is subsequently upgraded). The proceeds of this debt issuance were used for general corporate purposes, including the redemption of $500.0 million of 4.90% notes on March 11, 2021 that were scheduled to mature in December 2021. The Company redeemed those notes for $515.7 million, plus accrued interest. The call premium of $15.7 million was recorded to Interest Expense on Long-Term Debt on the Consolidated Income Statement during the quarter ended March 31, 2021.

Commitments And Contingencies

Commitments And Contingencies	6 Months Ended
	Mar. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments And Contingencies	Commitments and Contingencies Environmental Matters. The Company is subject to various federal, state and local laws and regulations relating to the protection of the environment. The Company has established procedures for the ongoing evaluation of its operations to identify potential environmental exposures and to comply with regulatory requirements. It is the Company’s policy to accrue estimated environmental clean-up costs (investigation and remediation) when such amounts can reasonably be estimated and it is probable that the Company will be required to incur such costs. At March 31, 2021, the Company has estimated its remaining clean-up costs related to former manufactured gas plant sites will be approximately $3.3 million, which includes a $0.5 million estimated minimum liability to remediate a former manufactured gas plant site located in New York. In March 2018, the NYDEC issued a Record of Decision for this New York site and the minimum liability reflects the remedy selected in the Record of Decision. Active remedial work at the site has been completed and restoration is currently underway. The Company's liability for such clean-up costs has been recorded in Other Deferred Credits on the Consolidated Balance Sheet at March 31, 2021. The Company expects to recover its environmental clean-up costs through rate recovery over a period of approximately 1 year and is currently not aware of any material additional exposure to environmental liabilities. However, changes in environmental laws and regulations, new information or other factors could have an adverse financial impact on the Company. Northern Access Project. On February 3, 2017, Supply Corporation and Empire received FERC approval of the Northern Access project described herein. Shortly thereafter, the NYDEC issued a Notice of Denial of the federal Clean Water Act Section 401 Water Quality Certification and other state stream and wetland permits for the New York portion of the project (the Water Quality Certification for the Pennsylvania portion of the project was received in January of 2017). The United States Court of Appeals for the Second Circuit (the “Second Circuit Court of Appeals”) held in the Company’s favor in its appeal of this decision, vacating the NYDEC denial and remanding to the NYDEC. The NYDEC subsequently issued a second denial, which the Company has appealed to the Second Circuit Court of Appeals. The court has held this appeal in abeyance pending the outcome of the FERC waiver appeal, described below. While the Company’s initial appeal was pending before the Second Circuit Court of Appeals, the FERC issued an Order finding that the NYDEC exceeded the statutory time frame to take action under the Clean Water Act and, therefore, waived its opportunity to approve or deny the Water Quality Certification. FERC denied rehearing requests associated with its Order and FERC's decisions were appealed. Recently, the Second Circuit Court of Appeals issued an order upholding the FERC waiver orders. In addition, in the Company's state court litigation challenging the NYDEC's actions with regard to various state permits, the New York State Supreme Court issued a decision finding these permits to be preempted. The Company remains committed to the project. Other. The Company is involved in other litigation and regulatory matters arising in the normal course of business. These other matters may include, for example, negligence claims and tax, regulatory or other governmental audits, inspections, investigations and other proceedings. These matters may involve state and federal taxes, safety, compliance with regulations, rate base, cost of service and purchased gas cost issues, among other things. While these other matters arising in the normal course of business could have a material effect on earnings and cash flows in the period in which they are resolved, an estimate of the possible loss or range of loss, if any, cannot be made at this time.

Business Segment Information

Business Segment Information	6 Months Ended
	Mar. 31, 2021
Segment Reporting [Abstract]
Business Segment Information	Business Segment Information The Company reports financial results for four segments: Exploration and Production, Pipeline and Storage, Gathering and Utility. The division of the Company’s operations into reportable segments is based upon a combination of factors including differences in products and services, regulatory environment and geographic factors. The data presented in the tables below reflect financial information for the segments and reconciliations to consolidated amounts. As stated in the 2020 Form 10-K, the Company evaluates segment performance based on income before discontinued operations (when applicable). When this is not applicable, the Company evaluates performance based on net income. There have not been any changes in the basis of segmentation nor in the basis of measuring segment profit or loss from those used in the Company’s 2020 Form 10-K. A listing of segment assets at March 31, 2021 and September 30, 2020 is shown in the tables below. Quarter Ended March 31, 2021 (Thousands) Exploration and Production Pipeline and Storage Gathering Utility Total Reportable Segments All Other Corporate and Intersegment Eliminations Total Consolidated Revenue from External Customers $220,187 $59,314 $671 $270,784 $550,956 $64 $95 $551,115 Intersegment Revenues $— $27,390 $49,591 $97 $77,078 $1 $(77,079) $— Segment Profit: Net Income (Loss) $36,822 $24,928 $20,700 $32,044 $114,494 $(983) $(1,075) $112,436 Six Months Ended March 31, 2021 (Thousands) Exploration and Production Pipeline and Storage Gathering Utility Total Reportable Segments All Other Corporate and Intersegment Eliminations Total Consolidated Revenue from External Customers $411,582 $118,623 $1,021 $459,684 $990,910 $1,175 $190 $992,275 Intersegment Revenues $— $55,846 $96,249 $197 $152,292 $20 $(152,312) $— Segment Profit: Net Income $7,199 $49,112 $41,250 $55,081 $152,642 $36,577 $991 $190,210 (Thousands) Exploration and Production Pipeline and Storage Gathering Utility Total Reportable Segments All Other Corporate and Intersegment Eliminations Total Consolidated Segment Assets: At March 31, 2021 $2,023,147 $2,240,140 $855,507 $2,151,304 $7,270,098 $27,391 $(181,837) $7,115,652 At September 30, 2020 $1,979,028 $2,204,971 $945,199 $2,067,852 $7,197,050 $113,571 $(345,686) $6,964,935 Quarter Ended March 31, 2020 (Thousands) Exploration and Production Pipeline and Storage Gathering Utility Total Reportable Segments All Other Corporate and Intersegment Eliminations Total Consolidated Revenue from External Customers $155,560 $51,919 $— $250,556 $458,035 $32,925 $135 $491,095 Intersegment Revenues $— $27,326 $35,267 $3,937 $66,530 $79 $(66,609) $— Segment Profit: Net Income (Loss) $(175,275) $22,087 $19,898 $31,499 $(101,791) $1,169 $(5,446) $(106,068) Six Months Ended March 31, 2020 (Thousands) Exploration and Production Pipeline and Storage Gathering Utility Total Reportable Segments All Other Corporate and Intersegment Eliminations Total Consolidated Revenue from External Customers $321,499 $100,888 $— $445,465 $867,852 $67,161 $270 $935,283 Intersegment Revenues $— $50,577 $70,055 $5,853 $126,485 $256 $(126,741) $— Segment Profit: Net Income (Loss) $(151,299) $40,192 $35,842 $58,082 $(17,183) $1,540 $(3,834) $(19,477)

Retirement Plan And Other Post-

Retirement Plan And Other Post-Retirement Benefits	6 Months Ended
	Mar. 31, 2021
Retirement Benefits [Abstract]
Retirement Plan and Other Post-Retirement Benefits	Retirement Plan and Other Post-Retirement Benefits Components of Net Periodic Benefit Cost (in thousands): Retirement Plan Other Post-Retirement Benefits Three Months Ended March 31, 2021 2020 2021 2020 Service Cost $ 2,466 $ 2,330 $ 400 $ 402 Interest Cost 5,422 7,483 2,326 3,228 Expected Return on Plan Assets (14,537) (15,016) (7,241) (7,308) Amortization of Prior Service Cost (Credit) 158 182 (107) (107) Amortization of Losses 9,203 9,846 212 134 Net Amortization and Deferral for Regulatory Purposes (Including Volumetric Adjustments) (1) 7,710 5,519 9,451 8,846 Net Periodic Benefit Cost $ 10,422 $ 10,344 $ 5,041 $ 5,195 Retirement Plan Other Post-Retirement Benefits Six Months Ended March 31, 2021 2020 2021 2020 Service Cost $ 4,932 $ 4,659 $ 801 $ 804 Interest Cost 10,843 14,965 4,652 6,457 Expected Return on Plan Assets (29,074) (30,032) (14,482) (14,616) Amortization of Prior Service Cost (Credit) 316 365 (214) (214) Amortization of Losses 18,407 19,692 424 267 Net Amortization and Deferral for Regulatory Purposes (Including Volumetric Adjustments) (1) 11,422 7,047 16,303 15,094 Net Periodic Benefit Cost $ 16,846 $ 16,696 $ 7,484 $ 7,792 (1) The Company’s policy is to record retirement plan and other post-retirement benefit costs in the Utility segment on a volumetric basis to reflect the fact that the Utility segment experiences higher throughput of natural gas in the winter months and lower throughput of natural gas in the summer months. The components of net periodic benefit cost other than service cost are presented in Other Income (Deductions) on the Consolidated Statements of Income.

Regulatory Matters

Regulatory Matters	6 Months Ended
	Mar. 31, 2021
Regulatory Assets and Liabilities, Other Disclosures [Abstract]
Regulatory Matters	Regulatory Matters New York Jurisdiction Distribution Corporation's current delivery rates in its New York jurisdiction were approved by the NYPSC in an order issued on April 20, 2017 with rates becoming effective May 1, 2017. The order provided for a return on equity of 8.7%. The order also directed the implementation of an earnings sharing mechanism to be in place beginning on April 1, 2018. In New York, on March 13, 2020, in response to the COVID-19 pandemic, the Company agreed to NYPSC Staff’s request that the Company suspend service terminations and disconnections. Thereafter, on June 17, 2020, New York enacted a new law that prohibits utilities from terminating or disconnecting services to any residential customer for non-payment for the duration of the state disaster emergency. In addition, the law prohibits residential terminations for non-payment for a period of 180 days running from the end of the state disaster emergency for customers that have experienced a change in financial circumstances due to the COVID-19 state of emergency. Governor Cuomo, through the issuance of executive orders, has extended the declaration of the state disaster emergency through May 25, 2021. Although the state disaster emergency declaration continues, the above-enumerated law reached its sunset on March 31, 2021. Legislation purporting to extend the moratorium is pending, and all of the major utilities have notified NYPSC Staff that they have no immediate plans to resume residential disconnections given the proposed legislation. The duration of the aforementioned suspension in New York and its related impact on the Company is uncertain. The Company is anticipating that customer non-payment may increase given higher natural gas usage and the resulting increase in costs for customers. It is uncertain at this point as to whether there would be any regulatory relief for utilities with regard to an increase in costs associated with the COVID-19 pandemic, but it is one of many issues currently being considered in a generic NYPSC proceeding entitled “Proceeding on Motion of the Commission Regarding the Effects of COVID-19 on Utility Service” (Case No. 20-M-0266). Correspondence from NYPSC Staff has recommended that utilities rely on existing avenues of relief for these costs, and has identified additional, more stringent requirements that must be met to achieve relief. Pennsylvania Jurisdiction Distribution Corporation’s current delivery rates in its Pennsylvania jurisdiction were approved by the PaPUC on November 30, 2006 as part of a settlement agreement that became effective January 1, 2007. The rate settlement does not specify any requirement to file a future rate case. On March 26, 2020, the PaPUC ratified an Emergency Order that established a Service Termination Moratorium intended to continue during the pendency of Governor Wolf’s March 6, 2020 Proclamation of Disaster Emergency associated with the COVID-19 pandemic. On May 13, 2020, the Company (and other Pennsylvania local distribution companies) received a Secretarial Letter from the PaPUC regarding COVID-19 pandemic cost tracking and regulatory assets. The Secretarial Letter directs utilities to track “extraordinary, nonrecurring incremental COVID-19 related expenses” so the Commission can understand the impact of these expenses on the utilities’ finances. It also authorizes the creation of a utility regulatory asset, but only for incremental uncollectible expenses incurred above those embedded in rates (and incurred since the issuance of the Emergency Order). The Company currently does not anticipate a need to create a regulatory asset for these expenses. On October 8, 2020, the Commission issued an order ending the moratorium effective November 9, 2020, imposing a list of enhanced customer protections that expired on March 31, 2021. On March 11, 2021, the Commission adopted an order confirming that effective April 1, 2021, the utility service termination moratorium would be lifted and utilities would be authorized to return to the regular collections process with certain modifications to customer payment arrangements. The October and March orders expanded the aforementioned potential utility regulatory asset to include all incremental COVID-19 related expenses incurred above those embedded in rates resulting from directives contained in the orders. The Company continues to monitor this item for potential deferral opportunity. FERC Jurisdiction Supply Corporation’s rate settlement, approved June 1, 2020, provides that no party may make a rate filing for new rates to be effective before February 1, 2024, except that Supply Corporation may file an NGA general Section 4 rate case to change rates if the corporate federal income tax rate is increased. If no case has been filed, Supply Corporation must file for rates to be effective February 1, 2025. Supply has no rate case currently on file. Empire’s 2019 rate settlement provides that Empire must make a rate case filing no later than May 1, 2025.

Summary Of Significant Accoun_2

Summary Of Significant Accounting Policies (Policy)	6 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation. The Company consolidates all entities in which it has a controlling financial interest. All significant intercompany balances and transactions are eliminated. The Company uses proportionate consolidation when accounting for drilling arrangements related to oil and gas producing properties accounted for under the full cost method of accounting. The preparation of the consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Earnings For Interim Periods	Earnings for Interim Periods. The Company, in its opinion, has included all adjustments (which consist of only normally recurring adjustments, unless otherwise disclosed in this Form 10-Q) that are necessary for a fair statement of the results of operations for the reported periods. The consolidated financial statements and notes thereto, included herein, should be read in conjunction with the financial statements and notes for the years ended September 30, 2020, 2019 and 2018 that are included in the Company's 2020 Form 10-K. The consolidated financial statements for the year ended September 30, 2021 will be audited by the Company's independent registered public accounting firm after the end of the fiscal year.
Consolidated Statements of Cash Flows	Consolidated Statements of Cash Flows. The components, as reported on the Company’s Consolidated Balance Sheets, of the total cash, cash equivalents, and restricted cash presented on the Statement of Cash Flows are as follows (in thousands): Six Months Ended Six Months Ended Balance at October 1, 2020 Balance at Balance at October 1, 2019 Balance at Cash and Temporary Cash Investments $ 20,541 $ 80,467 $ 20,428 $ 111,655 Hedging Collateral Deposits — — 6,832 10,728 Cash, Cash Equivalents, and Restricted Cash $ 20,541 $ 80,467 $ 27,260 $ 122,383 The Company considers all highly liquid debt instruments purchased with a maturity date of generally three months or less to be cash equivalents. The Company’s restricted cash is composed entirely of amounts reported as Hedging Collateral Deposits on the Consolidated Balance Sheets. Hedging Collateral Deposits is an account title for cash held in margin accounts funded by the Company to serve as collateral for hedging positions. In accordance with its accounting policy, the Company does not offset hedging collateral deposits paid or received against related derivative financial instruments liability or asset balances.
Allowance for Uncollectible Accounts	Allowance for Uncollectible Accounts. The allowance for uncollectible accounts is the Company’s best estimate of the amount of probable credit losses in the existing accounts receivable. The allowance is determined based on historical experience, the age of customer accounts, other specific information about customer accounts, and the economic environment. Account balances are charged off against the allowance twelve months after the account is final billed or when it is anticipated that the receivable will not be recovered. To date, as a result of the COVID-19 pandemic, the Company has started to see modest increases in their receivable balances due to customer non-payments. As a result, the Company has increased the bad debt reserve to account for the higher receivable balances. Activity in the allowance for uncollectible accounts for the six months ended March 31, 2021 are as follows: Balance at Beginning of Period Additions Charged to Costs and Expenses Add: Deduct: Balance at End of Period Six Months Ended March 31, 2021 Allowance for Uncollectible Accounts $ 22,810 $ 11,074 $ 737 $ 4,493 $ 30,128
Gas Stored Underground	Gas Stored Underground. In the Utility segment, gas stored underground is carried at lower of cost or net realizable value, on a LIFO method. Gas stored underground normally declines during the first and second quarters of the year and is replenished during the third and fourth quarters. In the Utility segment, the current cost of replacing gas withdrawn from storage is recorded in the Consolidated Statements of Income and a reserve for gas replacement is recorded in the Consolidated Balance Sheets under the caption “Other Accruals and Current Liabilities.” Such reserve, which amounted to $21.4 million at March 31, 2021, is reduced to zero by September 30 of each year as the inventory is replenished.
Materials, Supplies and Emission Allowances	Materials, Supplies and Emission Allowances. The components of the Company's materials, supplies and emission allowances are as follows: At March 31, 2021 At September 30, 2020 Materials and Supplies - at average cost $ 33,532 $ 33,859 Emission Allowances 18,680 18,018 $ 52,212 $ 51,877
Property, Plant and Equipment	Property, Plant and Equipment. In the Company’s Exploration and Production segment, oil and gas property acquisition, exploration and development costs are capitalized under the full cost method of accounting. Under this methodology, all costs associated with property acquisition, exploration and development activities are capitalized, including internal costs directly identified with acquisition, exploration and development activities. The internal costs that are capitalized do not include any costs related to production, general corporate overhead, or similar activities. The Company does not recognize any gain or loss on the sale or other disposition of oil and gas properties unless the gain or loss would significantly alter the relationship between capitalized costs and proved reserves of oil and gas attributable to a cost center. The Company's capitalized costs relating to oil and gas producing activities, net of accumulated depreciation, depletion and amortization, were $1.8 billion at both March 31, 2021 and September 30, 2020. Capitalized costs include costs related to unproved properties, which are excluded from amortization until proved reserves are found or it is determined that the unproved properties are impaired. Such costs amounted to $149.2 million and $148.1 million at March 31, 2021 and September 30, 2020, respectively. All costs related to unproved properties are reviewed quarterly to determine if impairment has occurred. The amount of any impairment is transferred to the pool of capitalized costs being amortized. Capitalized costs are subject to the SEC full cost ceiling test. The ceiling test, which is performed each quarter, determines a limit, or ceiling, on the amount of property acquisition, exploration and development costs that can be capitalized. The ceiling under this test represents (a) the present value of estimated future net cash flows, excluding future cash outflows associated with settling asset retirement obligations that have been accrued on the balance sheet, using a discount factor of 10%, which is computed by applying prices of oil and gas (as adjusted for hedging) to estimated future production of proved oil and gas reserves as of the date of the latest balance sheet, less estimated future expenditures, plus (b) the cost of unevaluated properties not being depleted, less (c) income tax effects related to the differences between the book and tax basis of the properties. The gas and oil prices used to calculate the full cost ceiling are based on an unweighted arithmetic average of the first day of the month oil and gas prices for each month within the twelve-month period prior to the end of the reporting period. If capitalized costs, net of accumulated depreciation, depletion and amortization and related deferred income taxes, exceed the ceiling at the end of any quarter, a permanent non-cash impairment is required to be charged to earnings in that quarter. At March 31, 2021, the ceiling exceeded the book value of the oil and gas properties by approximately $145.4 million. The book value of the oil and gas properties exceeded the ceiling at December 31, 2020. As such, the Company recognized a non-cash, pre-tax impairment charge of $76.2 million for the quarter ended December 31, 2020. A deferred income tax benefit of $21.0 million related to the non-cash impairment charge was also recognized for the quarter ended December 31, 2020. In adjusting estimated future cash flows for hedging under the ceiling test at March 31, 2021, estimated future net cash flows were increased by $127.9 million.
Accumulated Other Comprehensive Income (Loss)	Accumulated Other Comprehensive Income (Loss). The components of Accumulated Other Comprehensive Income (Loss) and changes for the six months ended March 31, 2021 and 2020, net of related tax effect, are as follows (amounts in parentheses indicate debits) (in thousands): Gains and Losses on Derivative Financial Instruments Funded Status of the Pension and Other Post-Retirement Benefit Plans Total Three Months Ended March 31, 2021 Balance at January 1, 2021 $ 10,151 $ (89,892) $ (79,741) Other Comprehensive Gains and Losses Before Reclassifications (24,903) — (24,903) Amounts Reclassified From Other Comprehensive Income (Loss) 2,656 — 2,656 Balance at March 31, 2021 $ (12,096) $ (89,892) $ (101,988) Six Months Ended March 31, 2021 Balance at October 1, 2020 $ (24,865) $ (89,892) $ (114,757) Other Comprehensive Gains and Losses Before Reclassifications 9,888 — 9,888 Amounts Reclassified From Other Comprehensive Income (Loss) 2,881 — 2,881 Balance at March 31, 2021 $ (12,096) $ (89,892) $ (101,988) Three Months Ended March 31, 2020 Balance at January 1, 2020 $ 30,680 $ (86,830) $ (56,150) Other Comprehensive Gains and Losses Before Reclassifications 55,450 — 55,450 Amounts Reclassified From Other Comprehensive Income (Loss) (18,217) — (18,217) Balance at March 31, 2020 $ 67,913 $ (86,830) $ (18,917) Six Months Ended March 31, 2020 Balance at October 1, 2019 $ 34,675 $ (86,830) $ (52,155) Other Comprehensive Gains and Losses Before Reclassifications 55,825 — 55,825 Amounts Reclassified From Other Comprehensive Income (Loss) (23,537) — (23,537) Cumulative Effect of Adoption of Authoritative Guidance for Hedging 950 — 950 Balance at March 31, 2020 $ 67,913 $ (86,830) $ (18,917)
Reclassifications Out of Accumulated Other Comprehensive Income (Loss)	Reclassifications Out of Accumulated Other Comprehensive Income (Loss). The details about the reclassification adjustments out of accumulated other comprehensive income (loss) for the six months ended March 31, 2021 and 2020 are as follows (amounts in parentheses indicate debits to the income statement) (in thousands): Details About Accumulated Other Comprehensive Income (Loss) Components Amount of Gain or (Loss) Reclassified from Accumulated Other Comprehensive Affected Line Item in the Statement Where Net Income is Presented Three Months Ended Six Months Ended March 31, 2021 2020 2021 2020 Gains (Losses) on Derivative Financial Instrument Cash Flow Hedges: Commodity Contracts ($3,761) $23,396 ($4,071) $30,937 Operating Revenues Commodity Contracts — 1,909 — 1,911 Purchased Gas Foreign Currency Contracts 95 (271) 94 (462) Operating Revenues (3,666) 25,034 (3,977) 32,386 Total Before Income Tax 1,010 (6,817) 1,096 (8,849) Income Tax Expense ($2,656) $18,217 ($2,881) $23,537 Net of Tax
Other Current Assets	Other Current Assets . The components of the Company’s Other Current Assets are as follows (in thousands): At March 31, 2021 At September 30, 2020 Prepayments $ 7,692 $ 12,851 Prepaid Property and Other Taxes 23,373 14,269 State Income Taxes Receivable — 3,828 Regulatory Assets 25,052 16,609 $ 56,117 $ 47,557
Other Accruals and Current Liabilities	Other Accruals and Current Liabilities . The components of the Company’s Other Accruals and Current Liabilities are as follows (in thousands): At March 31, 2021 At September 30, 2020 Accrued Capital Expenditures $ 49,526 $ 33,344 Regulatory Liabilities 34,832 44,890 Reserve for Gas Replacement 21,432 — Liability for Royalty and Working Interests 22,475 15,665 Non-Qualified Benefit Plan Liability 14,460 14,460 Other 34,215 31,817 $ 176,940 $ 140,176
Earnings Per Common Share	Earnings Per Common Share. Basic earnings per common share is computed by dividing income or loss by the weighted average number of common shares outstanding for the period. Diluted earnings per common share reflects the potential dilution that could occur if securities or other contracts to issue common stock were exercised or converted into common stock. For purposes of determining earnings per common share, the potentially dilutive securities the Company had outstanding were SARs, restricted stock units and performance shares. For the quarter and six months ended March 31, 2021, the diluted weighted average shares outstanding shown on the Consolidated Statements of Income reflects the potential dilution as a result of these securities as determined using the Treasury Stock Method. SARs, restricted stock units and performance shares that are antidilutive are excluded from the calculation of diluted earnings per common share. There were 334,945 securities excluded as being antidilutive for both the quarter and six months ended March 31, 2021. As the Company recognized a net
Stock-Based Compensation	Stock-Based Compensation. The Company granted 309,470 performance shares during the six months ended March 31, 2021. The weighted average fair value of such performance shares was $39.19 per share for the six months ended March 31, 2021. Performance shares are an award constituting units denominated in common stock of the Company, the number of which may be adjusted over a performance cycle based upon the extent to which performance goals have been satisfied. Earned performance shares may be distributed in the form of shares of common stock of the Company, an equivalent value in cash or a combination of cash and shares of common stock of the Company, as determined by the Company. The performance shares do not entitle the participant to receive dividends during the vesting period. Half of the performance shares granted during the six months ended March 31, 2021 must meet a performance goal related to relative return on capital over a three-year performance cycle. The performance goal over the performance cycle is the Company’s total return on capital relative to the total return on capital of other companies in a group selected by the Compensation Committee (“Report Group”). Total return on capital for a given company means the average of the Report Group companies’ returns on capital for each twelve month period corresponding to each of the Company’s fiscal years during the performance cycle, based on data reported for the Report Group companies in the Bloomberg database. The number of these performance shares that will vest and be paid will depend upon the Company’s performance relative to the Report Group and not upon the absolute level of return achieved by the Company. The fair value of these performance shares is calculated by multiplying the expected number of shares that will be issued by the average market price of Company common stock on the date of grant reduced by the present value of forgone dividends over the vesting term of the award. The fair value is recorded as compensation expense over the vesting term of the award. The other half of the performance shares granted during the six months ended March 31, 2021 must meet a performance goal related to relative total shareholder return over a three-year performance cycle. The performance goal over the performance cycle is the Company’s three-year total shareholder return relative to the three-year total shareholder return of the other companies in the Report Group. Three-year total shareholder return for a given company will be based on the data reported for that company (with the starting and ending stock prices over the performance cycle calculated as the average closing stock price for the prior calendar month and with dividends reinvested in that company’s securities at each ex-dividend date) in the Bloomberg database. The number of these total shareholder return performance shares ("TSR performance shares") that will vest and be paid will depend upon the Company’s performance relative to the Report Group and not upon the absolute level of return achieved by the Company. The fair value price at the date of grant for the TSR performance shares is determined using a Monte Carlo simulation technique, which includes a reduction in value for the present value of forgone dividends over the vesting term of the award. This price is multiplied by the number of TSR performance shares awarded, the result of which is recorded as compensation expense over the vesting term of the award. The Company granted 172,513 restricted stock units during the six months ended March 31, 2021. The weighted average fair value of such restricted stock units was $37.98 per share for the six months ended March 31, 2021. Restricted stock units represent the right to receive shares of common stock of the Company (or the equivalent value in cash or a combination of cash and shares of common stock of the Company, as determined by the Company) at the end of a specified time period. These restricted stock units do not entitle the participant to receive dividends during the vesting period. The accounting for restricted stock units is the same as the accounting for restricted share awards, except that the fair value at the date of grant of the restricted stock units must be reduced by the present value of forgone dividends over the vesting term of the award.
New Authoritative Accounting and Financial Reporting Guidance	New Authoritative Accounting and Financial Reporting Guidance. On October 1, 2020, the Company adopted authoritative guidance regarding the measurement of credit losses on financial assets measured at amortized cost. The new guidance requires financial assets measured at amortized cost to be presented at the net amount expected to be collected, which means that companies are required to recognize an allowance for credit losses for the difference between the amortized cost basis of the financial asset and the amount expected to be collected over the contractual life of the asset. Prior to adoption, the Company analyzed its financial assets measured at amortized cost, primarily trade receivables. The adoption of this guidance did not have a material impact to the Company’s financial statements.

Summary Of Significant Accoun_3

Summary Of Significant Accounting Policies (Tables)	6 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Schedule of Cash, Cash Equivalents and Restricted Cash	The components, as reported on the Company’s Consolidated Balance Sheets, of the total cash, cash equivalents, and restricted cash presented on the Statement of Cash Flows are as follows (in thousands): Six Months Ended Six Months Ended Balance at October 1, 2020 Balance at Balance at October 1, 2019 Balance at Cash and Temporary Cash Investments $ 20,541 $ 80,467 $ 20,428 $ 111,655 Hedging Collateral Deposits — — 6,832 10,728 Cash, Cash Equivalents, and Restricted Cash $ 20,541 $ 80,467 $ 27,260 $ 122,383
Schedule of Allowance for Uncollectible Accounts	Activity in the allowance for uncollectible accounts for the six months ended March 31, 2021 are as follows: Balance at Beginning of Period Additions Charged to Costs and Expenses Add: Deduct: Balance at End of Period Six Months Ended March 31, 2021 Allowance for Uncollectible Accounts $ 22,810 $ 11,074 $ 737 $ 4,493 $ 30,128
Schedule of Materials, Supplies and Emission Allowances	The components of the Company's materials, supplies and emission allowances are as follows: At March 31, 2021 At September 30, 2020 Materials and Supplies - at average cost $ 33,532 $ 33,859 Emission Allowances 18,680 18,018 $ 52,212 $ 51,877
Components of Accumulated Other Comprehensive Income (Loss)	The components of Accumulated Other Comprehensive Income (Loss) and changes for the six months ended March 31, 2021 and 2020, net of related tax effect, are as follows (amounts in parentheses indicate debits) (in thousands): Gains and Losses on Derivative Financial Instruments Funded Status of the Pension and Other Post-Retirement Benefit Plans Total Three Months Ended March 31, 2021 Balance at January 1, 2021 $ 10,151 $ (89,892) $ (79,741) Other Comprehensive Gains and Losses Before Reclassifications (24,903) — (24,903) Amounts Reclassified From Other Comprehensive Income (Loss) 2,656 — 2,656 Balance at March 31, 2021 $ (12,096) $ (89,892) $ (101,988) Six Months Ended March 31, 2021 Balance at October 1, 2020 $ (24,865) $ (89,892) $ (114,757) Other Comprehensive Gains and Losses Before Reclassifications 9,888 — 9,888 Amounts Reclassified From Other Comprehensive Income (Loss) 2,881 — 2,881 Balance at March 31, 2021 $ (12,096) $ (89,892) $ (101,988) Three Months Ended March 31, 2020 Balance at January 1, 2020 $ 30,680 $ (86,830) $ (56,150) Other Comprehensive Gains and Losses Before Reclassifications 55,450 — 55,450 Amounts Reclassified From Other Comprehensive Income (Loss) (18,217) — (18,217) Balance at March 31, 2020 $ 67,913 $ (86,830) $ (18,917) Six Months Ended March 31, 2020 Balance at October 1, 2019 $ 34,675 $ (86,830) $ (52,155) Other Comprehensive Gains and Losses Before Reclassifications 55,825 — 55,825 Amounts Reclassified From Other Comprehensive Income (Loss) (23,537) — (23,537) Cumulative Effect of Adoption of Authoritative Guidance for Hedging 950 — 950 Balance at March 31, 2020 $ 67,913 $ (86,830) $ (18,917)
Schedule of Reclassifications Out of Accumulated Other Comprehensive Income (Loss)	The details about the reclassification adjustments out of accumulated other comprehensive income (loss) for the six months ended March 31, 2021 and 2020 are as follows (amounts in parentheses indicate debits to the income statement) (in thousands): Details About Accumulated Other Comprehensive Income (Loss) Components Amount of Gain or (Loss) Reclassified from Accumulated Other Comprehensive Affected Line Item in the Statement Where Net Income is Presented Three Months Ended Six Months Ended March 31, 2021 2020 2021 2020 Gains (Losses) on Derivative Financial Instrument Cash Flow Hedges: Commodity Contracts ($3,761) $23,396 ($4,071) $30,937 Operating Revenues Commodity Contracts — 1,909 — 1,911 Purchased Gas Foreign Currency Contracts 95 (271) 94 (462) Operating Revenues (3,666) 25,034 (3,977) 32,386 Total Before Income Tax 1,010 (6,817) 1,096 (8,849) Income Tax Expense ($2,656) $18,217 ($2,881) $23,537 Net of Tax
Schedule of Other Current Assets	The components of the Company’s Other Current Assets are as follows (in thousands): At March 31, 2021 At September 30, 2020 Prepayments $ 7,692 $ 12,851 Prepaid Property and Other Taxes 23,373 14,269 State Income Taxes Receivable — 3,828 Regulatory Assets 25,052 16,609 $ 56,117 $ 47,557
Schedule of Other Accruals and Current Liabilities	The components of the Company’s Other Accruals and Current Liabilities are as follows (in thousands): At March 31, 2021 At September 30, 2020 Accrued Capital Expenditures $ 49,526 $ 33,344 Regulatory Liabilities 34,832 44,890 Reserve for Gas Replacement 21,432 — Liability for Royalty and Working Interests 22,475 15,665 Non-Qualified Benefit Plan Liability 14,460 14,460 Other 34,215 31,817 $ 176,940 $ 140,176

Revenue from Contracts with C_2

Revenue from Contracts with Customers (Tables)	6 Months Ended
	Mar. 31, 2021
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following tables provide a disaggregation of the Company's revenues for the quarter and six months ended March 31, 2021 and 2020, presented by type of service from each reportable segment. Quarter Ended March 31, 2021 (Thousands) Revenues By Type of Service Exploration and Production Pipeline and Storage Gathering Utility All Other Corporate and Intersegment Eliminations Total Consolidated Production of Natural Gas $ 188,769 $ — $ — $ — $ — $ — $ 188,769 Production of Crude Oil 33,589 — — — — — 33,589 Natural Gas Processing 772 — — — — — 772 Natural Gas Gathering Service — — 50,262 — — (49,591) 671 Natural Gas Transportation Service — 64,648 — 39,514 — (18,187) 85,975 Natural Gas Storage Service — 21,231 — — — (9,108) 12,123 Natural Gas Residential Sales — — — 203,768 — — 203,768 Natural Gas Commercial Sales — — — 28,872 — — 28,872 Natural Gas Industrial Sales — — — 1,368 — — 1,368 Natural Gas Marketing — — — — 66 (1) 65 Other 818 825 — (4,519) (1) (97) (2,974) Total Revenues from Contracts with Customers 223,948 86,704 50,262 269,003 65 (76,984) 552,998 Alternative Revenue Programs — — — 1,878 — — 1,878 Derivative Financial Instruments (3,761) — — — — — (3,761) Total Revenues $ 220,187 $ 86,704 $ 50,262 $ 270,881 $ 65 $ (76,984) $ 551,115 Six Months Ended March 31, 2021 (Thousands) Revenues By Type of Service Exploration and Production Pipeline and Storage Gathering Utility All Other Corporate and Intersegment Eliminations Total Consolidated Production of Natural Gas $ 355,212 $ — $ — $ — $ — $ — $ 355,212 Production of Crude Oil 58,088 — — — — — 58,088 Natural Gas Processing 1,324 — — — — — 1,324 Natural Gas Gathering Service — — 97,270 — — (96,249) 1,021 Natural Gas Transportation Service — 129,473 — 68,535 — (37,777) 160,231 Natural Gas Storage Service — 41,748 — — — (17,871) 23,877 Natural Gas Residential Sales — — — 341,649 — — 341,649 Natural Gas Commercial Sales — — — 46,067 — — 46,067 Natural Gas Industrial Sales — — — 2,290 — — 2,290 Natural Gas Marketing — — — — 650 (20) 630 Other 1,029 3,248 — (6,131) 545 (205) (1,514) Total Revenues from Contracts with Customers 415,653 174,469 97,270 452,410 1,195 (152,122) 988,875 Alternative Revenue Programs — — — 7,471 — — 7,471 Derivative Financial Instruments (4,071) — — — — — (4,071) Total Revenues $ 411,582 $ 174,469 $ 97,270 $ 459,881 $ 1,195 $ (152,122) $ 992,275 Quarter Ended March 31, 2020 (Thousands) Revenues By Type of Service Exploration and Production Pipeline and Storage Gathering Utility All Other Corporate and Intersegment Eliminations Total Consolidated Production of Natural Gas $ 100,777 $ — $ — $ — $ — $ — $ 100,777 Production of Crude Oil 30,268 — — — — — 30,268 Natural Gas Processing 714 — — — — — 714 Natural Gas Gathering Service — — 35,267 — — (35,267) — Natural Gas Transportation Service — 58,454 — 39,832 — (21,976) 76,310 Natural Gas Storage Service — 20,524 — — — (9,087) 11,437 Natural Gas Residential Sales — — — 185,323 — — 185,323 Natural Gas Commercial Sales — — — 27,296 — — 27,296 Natural Gas Industrial Sales — — — 1,144 — — 1,144 Natural Gas Marketing — — — — 36,404 (79) 36,325 Other 405 267 — (3,524) 851 (65) (2,066) Total Revenues from Contracts with Customers 132,164 79,245 35,267 250,071 37,255 (66,474) 467,528 Alternative Revenue Programs — — — 4,422 — — 4,422 Derivative Financial Instruments 23,396 — — — (4,251) — 19,145 Total Revenues $ 155,560 $ 79,245 $ 35,267 $ 254,493 $ 33,004 $ (66,474) $ 491,095 Six Months Ended March 31, 2020 (Thousands) Revenues By Type of Service Exploration and Production Pipeline and Storage Gathering Utility All Other Corporate and Intersegment Eliminations Total Consolidated Production of Natural Gas $ 220,651 $ — $ — $ — $ — $ — $ 220,651 Production of Crude Oil 67,931 — — — — — 67,931 Natural Gas Processing 1,402 — — — — — 1,402 Natural Gas Gathering Service — — 70,055 — — (70,055) — Natural Gas Transportation Service — 111,906 — 72,640 — (38,963) 145,583 Natural Gas Storage Service — 38,950 — — — (17,079) 21,871 Natural Gas Residential Sales — — — 329,693 — — 329,693 Natural Gas Commercial Sales — — — 46,137 — — 46,137 Natural Gas Industrial Sales — — — 2,413 — — 2,413 Natural Gas Marketing — — — — 70,513 (256) 70,257 Other 578 609 — (6,848) 1,971 (118) (3,808) Total Revenues from Contracts with Customers 290,562 151,465 70,055 444,035 72,484 (126,471) 902,130 Alternative Revenue Programs — — — 7,283 — — 7,283 Derivative Financial Instruments 30,937 — — — (5,067) — 25,870 Total Revenues $ 321,499 $ 151,465 $ 70,055 $ 451,318 $ 67,417 $ (126,471) $ 935,283

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Mar. 31, 2021
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The following table sets forth, by level within the fair value hierarchy, the Company's financial assets and liabilities (as applicable) that were accounted for at fair value on a recurring basis as of March 31, 2021 and September 30, 2020. Financial assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. The fair value presentation for over-the-counter swaps combines gas and oil swaps because a significant number of the counterparties enter into both gas and oil swap agreements with the Company. Recurring Fair Value Measures At fair value as of March 31, 2021 (Thousands of Dollars) Level 1 Level 2 Level 3 Netting Adjustments (1) Total (1) Assets: Cash Equivalents – Money Market Mutual Funds $ 66,759 $ — $ — $ — $ 66,759 Derivative Financial Instruments: Over the Counter Swaps – Gas and Oil — 18,805 — (14,768) 4,037 Over the Counter No Cost Collars – Gas — — — (118) (118) Foreign Currency Contracts — 1,437 — (1,252) 185 Other Investments: Balanced Equity Mutual Fund 32,993 — — — 32,993 Fixed Income Mutual Fund 70,133 — — — 70,133 Common Stock – Financial Services Industry 988 — — — 988 Total $ 170,873 $ 20,242 $ — $ (16,138) $ 174,977 Liabilities: Derivative Financial Instruments: Over the Counter Swaps – Gas and Oil — 35,809 — (14,768) 21,041 Over the Counter No Cost Collars – Gas — 1,488 — (118) 1,370 Foreign Currency Contracts — 72 — (1,252) (1,180) Total $ — $ 37,369 $ — $ (16,138) $ 21,231 Total Net Assets/(Liabilities) $ 170,873 $ (17,127) $ — $ — $ 153,746 Recurring Fair Value Measures At fair value as of September 30, 2020 (Thousands of Dollars) Level 1 Level 2 Level 3 Netting Adjustments (1) Total (1) Assets: Cash Equivalents – Money Market Mutual Funds $ 12,285 $ — $ — $ — $ 12,285 Derivative Financial Instruments: Over the Counter Swaps – Gas and Oil — 36,418 — (26,400) 10,018 Over the Counter No Cost Collars – Gas — — — (720) (720) Foreign Currency Contracts — 259 — (338) (79) Other Investments: Balanced Equity Mutual Fund 39,618 — — — 39,618 Fixed Income Mutual Fund 72,253 — — — 72,253 Common Stock – Financial Services Industry 639 — — — 639 Total $ 124,795 $ 36,677 $ — $ (27,458) $ 134,014 Liabilities: Derivative Financial Instruments: Over the Counter Swaps – Gas and Oil — 61,280 — (26,400) 34,880 Over the Counter No Cost Collars – Gas — 8,171 — (720) 7,451 Foreign Currency Contracts — 1,976 — (338) 1,638 Total $ — $ 71,427 $ — $ (27,458) $ 43,969 Total Net Assets/(Liabilities) $ 124,795 $ (34,750) $ — $ — $ 90,045 (1) Netting Adjustments represent the impact of legally-enforceable master netting arrangements that allow the Company to net gain and loss positions held with the same counterparties. The net asset or net liability for each counterparty is recorded as an asset or liability on the Company’s balance sheet.

Financial Instruments (Tables)

Financial Instruments (Tables)	6 Months Ended
	Mar. 31, 2021
Financial Instruments, Owned, at Fair Value [Abstract]
Long-Term Debt	Based on these criteria, the fair market value of long-term debt, including current portion, was as follows (in thousands): March 31, 2021 September 30, 2020 Carrying Fair Value Carrying Fair Value Long-Term Debt $ 2,627,033 $ 2,869,081 $ 2,629,576 $ 2,778,556
Schedule Of Other Investments	The components of the Company's Other Investments are as follows (in thousands): At March 31, 2021 At September 30, 2020 Life Insurance Contracts $ 43,307 $ 41,992 Equity Mutual Fund 32,993 39,618 Fixed Income Mutual Fund 70,133 72,253 Marketable Equity Securities 988 639 $ 147,421 $ 154,502
Schedule of Derivative Financial Instruments Designated And Qualifying As Cash Flow Hedges On The Statement Of Financial Performance	The Effect of Derivative Financial Instruments on the Statement of Financial Performance for the Three Months Ended March 31, 2021 and 2020 (Thousands of Dollars) Derivatives in Cash Flow Hedging Relationships Amount of Derivative Gain or (Loss) Recognized in Other Comprehensive Income (Loss) on Location of Derivative Gain or (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) on the Consolidated Balance Sheet into the Consolidated Statement of Income Amount of Derivative Gain or (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) on the Consolidated Balance Sheet into the Consolidated Statement of Income for the 2021 2020 2021 2020 Commodity Contracts $ (35,123) $ 81,108 Operating Revenue $ (3,761) $ 23,396 Commodity Contracts — (134) Purchased Gas — 1,909 Foreign Currency Contracts 750 (4,670) Operating Revenue 95 (271) Total $ (34,373) $ 76,304 $ (3,666) $ 25,034 The Effect of Derivative Financial Instruments on the Statement of Financial Performance for the Six Months Ended March 31, 2021 and 2020 (Thousands of Dollars) Derivatives in Cash Flow Hedging Relationships Amount of Derivative Gain or Location of Derivative Gain or (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) on the Consolidated Balance Sheet into the Consolidated Statement of Income Amount of Derivative Gain or 2021 2020 2021 2020 Commodity Contracts $ 10,472 $ 79,553 Operating Revenue $ (4,071) $ 30,937 Commodity Contracts — 997 Purchased Gas — 1,911 Foreign Currency Contracts 3,176 (3,751) Operating Revenue 94 (462) Total $ 13,648 $ 76,799 $ (3,977) $ 32,386

Capitalization (Tables)

Capitalization (Tables)	6 Months Ended
	Mar. 31, 2021
Capitalization, Long-term Debt and Equity [Abstract]
Summary of Changes in Common Stock Equity	Summary of Changes in Common Stock Equity Common Stock Paid In Earnings Accumulated Shares Amount (Thousands, except per share amounts) Balance at January 1, 2021 91,153 $ 91,153 $ 1,004,369 $ 1,028,844 $ (79,741) Net Income Available for Common Stock 112,436 Dividends Declared on Common Stock ($0.445 Per Share) (40,562) Other Comprehensive Loss, Net of Tax (22,247) Share-Based Payment Expense (1) 4,283 Common Stock Issued Under Stock and Benefit Plans 11 11 423 Balance at March 31, 2021 91,164 $ 91,164 $ 1,009,075 $ 1,100,718 $ (101,988) Balance at October 1, 2020 90,955 $ 90,955 $ 1,004,158 $ 991,630 $ (114,757) Net Income Available for Common Stock 190,210 Dividends Declared on Common Stock ($0.89 Per Share) (81,122) Other Comprehensive Income, Net of Tax 12,769 Share-Based Payment Expense (1) 7,779 Common Stock Issued (Repurchased) Under Stock and Benefit Plans 209 209 (2,862) Balance at March 31, 2021 91,164 $ 91,164 $ 1,009,075 $ 1,100,718 $ (101,988) Balance at January 1, 2020 86,552 $ 86,552 $ 831,146 $ 1,320,592 $ (56,150) Net Income (Loss) Available for Common Stock (106,068) Dividends Declared on Common Stock ($0.435 Per Share) (37,654) Other Comprehensive Income, Net of Tax 37,233 Share-Based Payment Expense (1) 3,876 Common Stock Issued Under Stock and Benefit Plans 10 10 422 Balance at March 31, 2020 86,562 $ 86,562 $ 835,444 $ 1,176,870 $ (18,917) Balance at October 1, 2019 86,315 $ 86,315 $ 832,264 $ 1,272,601 $ (52,155) Net Income (Loss) Available for Common Stock (19,477) Dividends Declared on Common Stock ($0.87 Per Share) (75,304) Cumulative Effect of Adoption of Authoritative Guidance for Hedging (950) Other Comprehensive Income, Net of Tax 33,238 Share-Based Payment Expense (1) 6,704 Common Stock Issued (Repurchased) Under Stock and Benefit Plans 247 247 (3,524) Balance at March 31, 2020 86,562 $ 86,562 $ 835,444 $ 1,176,870 $ (18,917) (1) Paid in Capital includes compensation costs associated with performance shares and/or restricted stock awards. The expense is included within Net Income Available For Common Stock, net of tax benefits.

Business Segment Information (T

Business Segment Information (Tables)	6 Months Ended
	Mar. 31, 2021
Segment Reporting [Abstract]
Financial Segment Information By Segment	Quarter Ended March 31, 2021 (Thousands) Exploration and Production Pipeline and Storage Gathering Utility Total Reportable Segments All Other Corporate and Intersegment Eliminations Total Consolidated Revenue from External Customers $220,187 $59,314 $671 $270,784 $550,956 $64 $95 $551,115 Intersegment Revenues $— $27,390 $49,591 $97 $77,078 $1 $(77,079) $— Segment Profit: Net Income (Loss) $36,822 $24,928 $20,700 $32,044 $114,494 $(983) $(1,075) $112,436 Six Months Ended March 31, 2021 (Thousands) Exploration and Production Pipeline and Storage Gathering Utility Total Reportable Segments All Other Corporate and Intersegment Eliminations Total Consolidated Revenue from External Customers $411,582 $118,623 $1,021 $459,684 $990,910 $1,175 $190 $992,275 Intersegment Revenues $— $55,846 $96,249 $197 $152,292 $20 $(152,312) $— Segment Profit: Net Income $7,199 $49,112 $41,250 $55,081 $152,642 $36,577 $991 $190,210 (Thousands) Exploration and Production Pipeline and Storage Gathering Utility Total Reportable Segments All Other Corporate and Intersegment Eliminations Total Consolidated Segment Assets: At March 31, 2021 $2,023,147 $2,240,140 $855,507 $2,151,304 $7,270,098 $27,391 $(181,837) $7,115,652 At September 30, 2020 $1,979,028 $2,204,971 $945,199 $2,067,852 $7,197,050 $113,571 $(345,686) $6,964,935 Quarter Ended March 31, 2020 (Thousands) Exploration and Production Pipeline and Storage Gathering Utility Total Reportable Segments All Other Corporate and Intersegment Eliminations Total Consolidated Revenue from External Customers $155,560 $51,919 $— $250,556 $458,035 $32,925 $135 $491,095 Intersegment Revenues $— $27,326 $35,267 $3,937 $66,530 $79 $(66,609) $— Segment Profit: Net Income (Loss) $(175,275) $22,087 $19,898 $31,499 $(101,791) $1,169 $(5,446) $(106,068) Six Months Ended March 31, 2020 (Thousands) Exploration and Production Pipeline and Storage Gathering Utility Total Reportable Segments All Other Corporate and Intersegment Eliminations Total Consolidated Revenue from External Customers $321,499 $100,888 $— $445,465 $867,852 $67,161 $270 $935,283 Intersegment Revenues $— $50,577 $70,055 $5,853 $126,485 $256 $(126,741) $— Segment Profit: Net Income (Loss) $(151,299) $40,192 $35,842 $58,082 $(17,183) $1,540 $(3,834) $(19,477)

Retirement Plan And Other Pos_2

Retirement Plan And Other Post-Retirement Benefits (Tables)	6 Months Ended
	Mar. 31, 2021
Retirement Benefits [Abstract]
Components of Net Periodic Benefit Cost	Components of Net Periodic Benefit Cost (in thousands): Retirement Plan Other Post-Retirement Benefits Three Months Ended March 31, 2021 2020 2021 2020 Service Cost $ 2,466 $ 2,330 $ 400 $ 402 Interest Cost 5,422 7,483 2,326 3,228 Expected Return on Plan Assets (14,537) (15,016) (7,241) (7,308) Amortization of Prior Service Cost (Credit) 158 182 (107) (107) Amortization of Losses 9,203 9,846 212 134 Net Amortization and Deferral for Regulatory Purposes (Including Volumetric Adjustments) (1) 7,710 5,519 9,451 8,846 Net Periodic Benefit Cost $ 10,422 $ 10,344 $ 5,041 $ 5,195 Retirement Plan Other Post-Retirement Benefits Six Months Ended March 31, 2021 2020 2021 2020 Service Cost $ 4,932 $ 4,659 $ 801 $ 804 Interest Cost 10,843 14,965 4,652 6,457 Expected Return on Plan Assets (29,074) (30,032) (14,482) (14,616) Amortization of Prior Service Cost (Credit) 316 365 (214) (214) Amortization of Losses 18,407 19,692 424 267 Net Amortization and Deferral for Regulatory Purposes (Including Volumetric Adjustments) (1) 11,422 7,047 16,303 15,094 Net Periodic Benefit Cost $ 16,846 $ 16,696 $ 7,484 $ 7,792 (1) The Company’s policy is to record retirement plan and other post-retirement benefit costs in the Utility segment on a volumetric basis to reflect the fact that the Utility segment experiences higher throughput of natural gas in the winter months and lower throughput of natural gas in the summer months.

Summary Of Significant Accoun_4

Summary Of Significant Accounting Policies (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended			6 Months Ended		12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020	Sep. 30, 2020	Sep. 30, 2021	Dec. 31, 2019	Sep. 30, 2019
Summary Of Significant Accounting Policies [Line Items]
Gas Stored Underground	$ 5,745			$ 5,745		$ 33,338
Capitalized Costs Oil and Gas Producing Activities Net	$ 1,800,000			1,800,000		1,800,000
Capitalized costs of unproved properties excluded from amortization				$ 149,200		148,100
Full cost ceiling test discount factor	10.00%			10.00%
Impairment of Oil and Gas Producing Properties	$ 0	$ 76,200	$ 177,761	$ 76,152	$ 177,761
Increase estimated future net cash flows	$ 127,900
Antidilutive securities	334,945		310,015	334,945	406,748
Retained Earnings (Accumulated Deficit)	$ 1,100,718	1,028,844	$ 1,176,870	$ 1,100,718	$ 1,176,870	991,630		$ 1,320,592	$ 1,272,601
Amount Full Cost Ceiling Exceeds Book Value Of Oil And Gas Properties	145,400			145,400
Earnings Reinvested in The Business [Member]
Summary Of Significant Accounting Policies [Line Items]
Retained Earnings (Accumulated Deficit)	1,100,718	1,028,844	$ 1,176,870	1,100,718	$ 1,176,870	991,630		1,320,592	1,272,601
Reserve For Gas Replacement [Member]
Summary Of Significant Accounting Policies [Line Items]
Gas Stored Underground	$ 21,432			$ 21,432		0
Impairment of Oil and Gas Producing Properties [Member]
Summary Of Significant Accounting Policies [Line Items]
Deferred Income Tax Benefit		21,000
Restricted Stock Units [Member]
Summary Of Significant Accounting Policies [Line Items]
Share based compensation other than options grants in period				172,513
Granted in fiscal year, weighted average grant date fair value				$ 37.98
Performance Shares [Member]
Summary Of Significant Accounting Policies [Line Items]
Share based compensation other than options grants in period				309,470
Granted in fiscal year, weighted average grant date fair value				$ 39.19
Subsequent Event [Member] | Reserve For Gas Replacement [Member]
Summary Of Significant Accounting Policies [Line Items]
Gas Stored Underground							$ 0
Guidance for Hedging [Member] | Cumulative Effect of Adoption of Authoritative Guidance [Member]
Summary Of Significant Accounting Policies [Line Items]
Retained Earnings (Accumulated Deficit)		$ 0				$ 0		$ 0	(950)
Increase (Decrease) to Accumulated Other Comprehensive Income									1,000
Guidance for Hedging [Member] | Cumulative Effect of Adoption of Authoritative Guidance [Member] | Earnings Reinvested in The Business [Member]
Summary Of Significant Accounting Policies [Line Items]
Retained Earnings (Accumulated Deficit)									$ (950)

Summary Of Significant Accoun_5

Summary Of Significant Accounting Policies (Consolidated Statements Of Cash Flows) (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Sep. 30, 2020	Mar. 31, 2020	Sep. 30, 2019
Cash and Cash Equivalents [Line Items]
Cash and Temporary Cash Investments	$ 80,467	$ 20,541	$ 111,655	$ 20,428
Hedging Collateral Deposits	0	0	10,728	6,832
Cash, Cash Equivalents and Restricted Cash	$ 80,467	$ 20,541	$ 122,383	$ 27,260

Summary Of Significant Accoun_6

Summary Of Significant Accounting Policies (Allowance for Uncollectible Accounts) (Details)	6 Months Ended
	Mar. 31, 2021USD ($)
Allowance for Uncollectible Accounts [Roll Forward]
Balance at Beginning of Period	$ 22,810
Additions Charged to Costs and Expenses	11,074
Add: Discounts on Purchased Receivables	737
Deduct: Net Accounts Receivable Written-Off	4,493
Balance at End of Period	$ 30,128

Summary of Significant Account

Summary of Significant Account Policies (Materials, Supplies and Emission Allowances) (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Sep. 30, 2020
Materials, Supplies and Emission Allowances [Line Items]
Materials and Supplies - at average cost	$ 33,532	$ 33,859
Emission Allowances	18,680	18,018
Materials, Supplies and Emission Allowances	$ 52,212	$ 51,877

Summary Of Significant Accoun_7

Summary Of Significant Accounting Policies (Components Of Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at Beginning of Period	$ (79,741)	$ (56,150)	$ (114,757)	$ (52,155)
Other Comprehensive Gains and Losses Before Reclassifications	(24,903)	55,450	9,888	55,825
Amounts Reclassified From Other Comprehensive Income (Loss)	2,656	(18,217)	2,881	(23,537)
Cumulative Effect of Adoption of Authoritative Guidance for Hedging				950
Balance at End of Period	(101,988)	(18,917)	(101,988)	(18,917)
Gains And Losses On Derivative Financial Instruments [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at Beginning of Period	10,151	30,680	(24,865)	34,675
Other Comprehensive Gains and Losses Before Reclassifications	(24,903)	55,450	9,888	55,825
Amounts Reclassified From Other Comprehensive Income (Loss)	2,656	(18,217)	2,881	(23,537)
Cumulative Effect of Adoption of Authoritative Guidance for Hedging				950
Balance at End of Period	(12,096)	67,913	(12,096)	67,913
Funded Status Of The Pension And Other Post-Retirement Benefit Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at Beginning of Period	(89,892)	(86,830)	(89,892)	(86,830)
Other Comprehensive Gains and Losses Before Reclassifications	0	0	0	0
Amounts Reclassified From Other Comprehensive Income (Loss)	0	0	0	0
Cumulative Effect of Adoption of Authoritative Guidance for Hedging				0
Balance at End of Period	$ (89,892)	$ (86,830)	$ (89,892)	$ (86,830)

Summary Of Significant Accoun_8

Summary Of Significant Accounting Policies (Reclassification Out Of Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020
Reclassification Adjustment out of Accumulated Other Comprehensive Income (Loss) [Line Items]
Operating Revenues	$ 551,115	$ 491,095	$ 992,275	$ 935,283
Purchased Gas	106,661	118,270	158,280	210,542
Other Income (Deductions)	(10,875)	(17,480)	(13,051)	(20,520)
Income (Loss) Before Income Taxes	152,646	(69,222)	259,837	48,764
Income Tax Expense	(40,210)	(36,846)	(69,627)	(68,241)
Net Income (Loss) Available for Common Stock	112,436	(106,068)	190,210	(19,477)
Amount Of Gain Or (Loss) Reclassified From Accumulated Other Comprehensive Income (Loss) [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income (Loss) [Line Items]
Income (Loss) Before Income Taxes	(3,666)	25,034	(3,977)	32,386
Income Tax Expense	1,010	(6,817)	1,096	(8,849)
Net Income (Loss) Available for Common Stock	(2,656)	18,217	(2,881)	23,537
Amount Of Gain Or (Loss) Reclassified From Accumulated Other Comprehensive Income (Loss) [Member] | Commodity Contracts [Member] | Gains And Losses On Derivative Financial Instruments [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income (Loss) [Line Items]
Operating Revenues	(3,761)	23,396	(4,071)	30,937
Purchased Gas [Member] | Amount Of Gain Or (Loss) Reclassified From Accumulated Other Comprehensive Income (Loss) [Member] | Commodity Contracts [Member] | Gains And Losses On Derivative Financial Instruments [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income (Loss) [Line Items]
Purchased Gas	0	1,909	0	1,911
Foreign Currency Contracts [Member] | Amount Of Gain Or (Loss) Reclassified From Accumulated Other Comprehensive Income (Loss) [Member] | Gains And Losses On Derivative Financial Instruments [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income (Loss) [Line Items]
Operating Revenues	$ 95	$ (271)	$ 94	$ (462)

Summary Of Significant Accoun_9

Summary Of Significant Accounting Policies (Components Of Other Current Assets) (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Sep. 30, 2020
Summary Of Significant Accounting Policies [Line Items]
Prepayments	$ 7,692	$ 12,851
Prepaid Property and Other Taxes	23,373	14,269
Regulatory Assets	25,052	16,609
Other Current Assets	56,117	47,557
State [Member]
Summary Of Significant Accounting Policies [Line Items]
Income Taxes Receivable	$ 0	$ 3,828

Summary Of Significant Accou_10

Summary Of Significant Accounting Policies (Schedule Of Other Accruals And Current Liabilities) (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Sep. 30, 2020
Summary Of Significant Accounting Policies [Line Items]
Regulatory Liabilities	$ 34,832	$ 44,890
Reserve for Gas Replacement	5,745	33,338
Liability for Royalty and Working Interests	22,475	15,665
Other Accruals and Current Liabilities	176,940	140,176
Accrued Capital Expenditures [Member]
Summary Of Significant Accounting Policies [Line Items]
Other	49,526	33,344
Reserve For Gas Replacement [Member]
Summary Of Significant Accounting Policies [Line Items]
Reserve for Gas Replacement	21,432	0
Other Accruals [Member]
Summary Of Significant Accounting Policies [Line Items]
Other	34,215	31,817
Non-Qualified [Member] | Current [Member]
Summary Of Significant Accounting Policies [Line Items]
Non-Qualified Benefit Plan Liability	$ 14,460	$ 14,460

Asset Acquisitions and Divest_2

Asset Acquisitions and Divestitures (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020	Sep. 30, 2020
Asset Acquisition and Divestitures [Line Items]
Total Consideration for Asset Acquisition					$ 506,300
Assets Held for Sale, Net	$ 0		$ 0		$ 53,424
Net Proceeds from Sale of Timber Properties			104,582	$ 0
Gain on Sale of Timber Properties	$ 0	$ 0	$ 51,066	$ 0

Revenue from Contracts with C_3

Revenue from Contracts with Customers (Narrative) (Details) $ in Millions	Mar. 31, 2021USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-04-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Future Revenue Amounts Related to Remaining Performance Obligations	$ 94.6
Remaining Performance Obligation, Expected Timing of Satisfaction	6 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Future Revenue Amounts Related to Remaining Performance Obligations	$ 179.7
Remaining Performance Obligation, Expected Timing of Satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Future Revenue Amounts Related to Remaining Performance Obligations	$ 144.5
Remaining Performance Obligation, Expected Timing of Satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Future Revenue Amounts Related to Remaining Performance Obligations	$ 124.3
Remaining Performance Obligation, Expected Timing of Satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Future Revenue Amounts Related to Remaining Performance Obligations	$ 117
Remaining Performance Obligation, Expected Timing of Satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Future Revenue Amounts Related to Remaining Performance Obligations	$ 517.5
Remaining Performance Obligation, Expected Timing of Satisfaction

Revenue from Contracts with C_4

Revenue from Contracts with Customers (Disaggregation of Revenue) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020
Disaggregation of Revenue [Line Items]
Revenue	$ 551,115	$ 491,095	$ 992,275	$ 935,283
Exploration And Production [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	223,948	132,164	415,653	290,562
Alternative Revenue Programs Outside Scope of Authoritative Guidance on Revenue Recognition	0	0	0	0
Derivative Financial Instruments Outside Scope of Authoritative Guidance on Revenue Recognition	(3,761)	23,396	(4,071)	30,937
Revenue	220,187	155,560	411,582	321,499
Pipeline And Storage [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	86,704	79,245	174,469	151,465
Alternative Revenue Programs Outside Scope of Authoritative Guidance on Revenue Recognition	0	0	0	0
Derivative Financial Instruments Outside Scope of Authoritative Guidance on Revenue Recognition	0	0	0	0
Revenue	86,704	79,245	174,469	151,465
Gathering [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	50,262	35,267	97,270	70,055
Alternative Revenue Programs Outside Scope of Authoritative Guidance on Revenue Recognition	0	0	0	0
Derivative Financial Instruments Outside Scope of Authoritative Guidance on Revenue Recognition	0	0	0	0
Revenue	50,262	35,267	97,270	70,055
Utility [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	269,003	250,071	452,410	444,035
Alternative Revenue Programs Outside Scope of Authoritative Guidance on Revenue Recognition	1,878	4,422	7,471	7,283
Derivative Financial Instruments Outside Scope of Authoritative Guidance on Revenue Recognition	0	0	0	0
Revenue	270,881	254,493	459,881	451,318
All Other [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	65	37,255	1,195	72,484
Alternative Revenue Programs Outside Scope of Authoritative Guidance on Revenue Recognition	0	0	0	0
Derivative Financial Instruments Outside Scope of Authoritative Guidance on Revenue Recognition	0	(4,251)	0	(5,067)
Revenue	65	33,004	1,195	67,417
Corporate And Intersegment Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	(76,984)	(66,474)	(152,122)	(126,471)
Alternative Revenue Programs Outside Scope of Authoritative Guidance on Revenue Recognition	0	0	0	0
Derivative Financial Instruments Outside Scope of Authoritative Guidance on Revenue Recognition	0	0	0	0
Revenue	(76,984)	(66,474)	(152,122)	(126,471)
Total Consolidated [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	552,998	467,528	988,875	902,130
Alternative Revenue Programs Outside Scope of Authoritative Guidance on Revenue Recognition	1,878	4,422	7,471	7,283
Derivative Financial Instruments Outside Scope of Authoritative Guidance on Revenue Recognition	(3,761)	19,145	(4,071)	25,870
Revenue	551,115	491,095	992,275	935,283
Production of Natural Gas [Member] | Exploration And Production [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	188,769	100,777	355,212	220,651
Production of Natural Gas [Member] | Pipeline And Storage [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
Production of Natural Gas [Member] | Gathering [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
Production of Natural Gas [Member] | Utility [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
Production of Natural Gas [Member] | All Other [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
Production of Natural Gas [Member] | Corporate And Intersegment Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
Production of Natural Gas [Member] | Total Consolidated [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	188,769	100,777	355,212	220,651
Production of Crude Oil [Member] | Exploration And Production [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	33,589	30,268	58,088	67,931
Production of Crude Oil [Member] | Pipeline And Storage [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
Production of Crude Oil [Member] | Gathering [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
Production of Crude Oil [Member] | Utility [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
Production of Crude Oil [Member] | All Other [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
Production of Crude Oil [Member] | Corporate And Intersegment Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
Production of Crude Oil [Member] | Total Consolidated [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	33,589	30,268	58,088	67,931
Natural Gas Processing [Member] | Exploration And Production [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	772	714	1,324	1,402
Natural Gas Processing [Member] | Pipeline And Storage [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
Natural Gas Processing [Member] | Gathering [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
Natural Gas Processing [Member] | Utility [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
Natural Gas Processing [Member] | All Other [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
Natural Gas Processing [Member] | Corporate And Intersegment Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
Natural Gas Processing [Member] | Total Consolidated [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	772	714	1,324	1,402
Natural Gas Gathering Service [Member] | Exploration And Production [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
Natural Gas Gathering Service [Member] | Pipeline And Storage [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
Natural Gas Gathering Service [Member] | Gathering [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	50,262	35,267	97,270	70,055
Natural Gas Gathering Service [Member] | Utility [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
Natural Gas Gathering Service [Member] | All Other [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
Natural Gas Gathering Service [Member] | Corporate And Intersegment Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	(49,591)	(35,267)	(96,249)	(70,055)
Natural Gas Gathering Service [Member] | Total Consolidated [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	671	0	1,021	0
Natural Gas Transportation Service [Member] | Exploration And Production [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
Natural Gas Transportation Service [Member] | Pipeline And Storage [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	64,648	58,454	129,473	111,906
Natural Gas Transportation Service [Member] | Gathering [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
Natural Gas Transportation Service [Member] | Utility [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	39,514	39,832	68,535	72,640
Natural Gas Transportation Service [Member] | All Other [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
Natural Gas Transportation Service [Member] | Corporate And Intersegment Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	(18,187)	(21,976)	(37,777)	(38,963)
Natural Gas Transportation Service [Member] | Total Consolidated [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	85,975	76,310	160,231	145,583
Natural Gas Storage Service [Member] | Exploration And Production [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
Natural Gas Storage Service [Member] | Pipeline And Storage [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	21,231	20,524	41,748	38,950
Natural Gas Storage Service [Member] | Gathering [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
Natural Gas Storage Service [Member] | Utility [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
Natural Gas Storage Service [Member] | All Other [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
Natural Gas Storage Service [Member] | Corporate And Intersegment Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	(9,108)	(9,087)	(17,871)	(17,079)
Natural Gas Storage Service [Member] | Total Consolidated [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	12,123	11,437	23,877	21,871
Natural Gas Residential Sales [Member] | Exploration And Production [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
Natural Gas Residential Sales [Member] | Pipeline And Storage [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
Natural Gas Residential Sales [Member] | Gathering [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
Natural Gas Residential Sales [Member] | Utility [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	203,768	185,323	341,649	329,693
Natural Gas Residential Sales [Member] | All Other [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
Natural Gas Residential Sales [Member] | Corporate And Intersegment Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
Natural Gas Residential Sales [Member] | Total Consolidated [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	203,768	185,323	341,649	329,693
Natural Gas Commercial Sales [Member] | Exploration And Production [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
Natural Gas Commercial Sales [Member] | Pipeline And Storage [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
Natural Gas Commercial Sales [Member] | Gathering [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
Natural Gas Commercial Sales [Member] | Utility [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	28,872	27,296	46,067	46,137
Natural Gas Commercial Sales [Member] | All Other [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
Natural Gas Commercial Sales [Member] | Corporate And Intersegment Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
Natural Gas Commercial Sales [Member] | Total Consolidated [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	28,872	27,296	46,067	46,137
Natural Gas Industrial Sales [Member] | Exploration And Production [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
Natural Gas Industrial Sales [Member] | Pipeline And Storage [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
Natural Gas Industrial Sales [Member] | Gathering [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
Natural Gas Industrial Sales [Member] | Utility [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	1,368	1,144	2,290	2,413
Natural Gas Industrial Sales [Member] | All Other [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
Natural Gas Industrial Sales [Member] | Corporate And Intersegment Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
Natural Gas Industrial Sales [Member] | Total Consolidated [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	1,368	1,144	2,290	2,413
Natural Gas Marketing [Member] | Exploration And Production [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
Natural Gas Marketing [Member] | Pipeline And Storage [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
Natural Gas Marketing [Member] | Gathering [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
Natural Gas Marketing [Member] | Utility [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
Natural Gas Marketing [Member] | All Other [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	66	36,404	650	70,513
Natural Gas Marketing [Member] | Corporate And Intersegment Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	(1)	(79)	(20)	(256)
Natural Gas Marketing [Member] | Total Consolidated [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	65	36,325	630	70,257
Other [Member] | Exploration And Production [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	818	405	1,029	578
Other [Member] | Pipeline And Storage [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	825	267	3,248	609
Other [Member] | Gathering [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	0	0	0	0
Other [Member] | Utility [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	(4,519)	(3,524)	(6,131)	(6,848)
Other [Member] | All Other [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	(1)	851	545	1,971
Other [Member] | Corporate And Intersegment Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	(97)	(65)	(205)	(118)
Other [Member] | Total Consolidated [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contracts with Customers	$ (2,974)	$ (2,066)	$ (1,514)	$ (3,808)

Fair Value Measurements (Narrat

Fair Value Measurements (Narrative) (Details) - USD ($)	Mar. 31, 2021	Sep. 30, 2020	Mar. 31, 2020	Sep. 30, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Hedging collateral deposits	$ 0	$ 0	$ 10,728,000	$ 6,832,000
Derivative Financial Instruments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Level 3 Fair Value	$ 0		$ 0

Fair Value Measurements (Recurr

Fair Value Measurements (Recurring Fair Value Measures Of Assets And Liabilities) (Details) - USD ($) $ in Thousands		Mar. 31, 2021		Sep. 30, 2020	Mar. 31, 2020	Sep. 30, 2019
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Cash Equivalents - Money Market Mutual Funds	[1]	$ 66,759		$ 12,285
Hedging Collateral Deposits		0		0	$ 10,728	$ 6,832
Total Assets	[1]	174,977		134,014
Total Liabilities	[1]	21,231		43,969
Total Net Assets/(Liabilities)	[1]	153,746		90,045
Over the Counter No Cost Collars - Gas [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative Asset		(118)	[1]	(720)
Derivative Liability		1,370	[1]	7,451
Foreign Currency Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative Asset	[1]	185		(79)
Derivative Liability	[1]	(1,180)		1,638
Balanced Equity Mutual Fund [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Other Investments	[1]	32,993		39,618
Fixed Income Mutual Fund [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Other Investments	[1]	70,133		72,253
Common Stock - Financial Services Industry [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Other Investments	[1]	988		639
Over The Counter Swaps - Gas And Oil [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative Asset	[1]	4,037		10,018
Derivative Liability	[1]	21,041		34,880
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Cash Equivalents - Money Market Mutual Funds		66,759		12,285
Total Assets		170,873		124,795
Total Liabilities		0		0
Total Net Assets/(Liabilities)		170,873		124,795
Fair Value, Inputs, Level 1 [Member] | Over the Counter No Cost Collars - Gas [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative Asset		0		0
Derivative Liability		0		0
Fair Value, Inputs, Level 1 [Member] | Foreign Currency Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative Asset		0		0
Derivative Liability		0		0
Fair Value, Inputs, Level 1 [Member] | Balanced Equity Mutual Fund [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Other Investments		32,993		39,618
Fair Value, Inputs, Level 1 [Member] | Fixed Income Mutual Fund [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Other Investments		70,133		72,253
Fair Value, Inputs, Level 1 [Member] | Common Stock - Financial Services Industry [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Other Investments		988		639
Fair Value, Inputs, Level 1 [Member] | Over The Counter Swaps - Gas And Oil [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative Asset		0		0
Derivative Liability		0		0
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Cash Equivalents - Money Market Mutual Funds		0		0
Total Assets		20,242		36,677
Total Liabilities		37,369		71,427
Total Net Assets/(Liabilities)		(17,127)		(34,750)
Fair Value, Inputs, Level 2 [Member] | Over the Counter No Cost Collars - Gas [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative Asset		0		0
Derivative Liability		1,488		8,171
Fair Value, Inputs, Level 2 [Member] | Foreign Currency Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative Asset		1,437		259
Derivative Liability		72		1,976
Fair Value, Inputs, Level 2 [Member] | Balanced Equity Mutual Fund [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Other Investments		0		0
Fair Value, Inputs, Level 2 [Member] | Fixed Income Mutual Fund [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Other Investments		0		0
Fair Value, Inputs, Level 2 [Member] | Common Stock - Financial Services Industry [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Other Investments		0		0
Fair Value, Inputs, Level 2 [Member] | Over The Counter Swaps - Gas And Oil [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative Asset		18,805		36,418
Derivative Liability		35,809		61,280
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Cash Equivalents - Money Market Mutual Funds		0		0
Total Assets		0		0
Total Liabilities		0		0
Total Net Assets/(Liabilities)		0		0
Fair Value, Inputs, Level 3 [Member] | Over the Counter No Cost Collars - Gas [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative Asset		0		0
Derivative Liability		0		0
Fair Value, Inputs, Level 3 [Member] | Foreign Currency Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative Asset		0		0
Derivative Liability		0		0
Fair Value, Inputs, Level 3 [Member] | Balanced Equity Mutual Fund [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Other Investments		0		0
Fair Value, Inputs, Level 3 [Member] | Fixed Income Mutual Fund [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Other Investments		0		0
Fair Value, Inputs, Level 3 [Member] | Common Stock - Financial Services Industry [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Other Investments		0		0
Fair Value, Inputs, Level 3 [Member] | Over The Counter Swaps - Gas And Oil [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative Asset		0		0
Derivative Liability		0		0
Netting Adjustments [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Cash Equivalents - Money Market Mutual Funds	[1]	0		0
Total Assets	[1]	(16,138)		(27,458)
Total Liabilities	[1]	(16,138)		(27,458)
Total Net Assets/(Liabilities)	[1]	0		0
Netting Adjustments [Member] | Over the Counter No Cost Collars - Gas [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative Asset		(118)	[1]	(720)
Derivative Liability		(118)	[1]	(720)
Netting Adjustments [Member] | Foreign Currency Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative Asset	[1]	(1,252)		(338)
Derivative Liability	[1]	(1,252)		(338)
Netting Adjustments [Member] | Balanced Equity Mutual Fund [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Other Investments	[1]	0		0
Netting Adjustments [Member] | Fixed Income Mutual Fund [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Other Investments	[1]	0		0
Netting Adjustments [Member] | Common Stock - Financial Services Industry [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Other Investments	[1]	0		0
Netting Adjustments [Member] | Over The Counter Swaps - Gas And Oil [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative Asset	[1]	(14,768)		(26,400)
Derivative Liability	[1]	$ (14,768)		$ (26,400)
[1]	Netting Adjustments represent the impact of legally-enforceable master netting arrangements that allow the Company to net gain and loss positions held with the same counterparties. The net asset or net liability for each counterparty is recorded as an asset or liability on the Company’s balance sheet.

Financial Instruments (Narrativ

Financial Instruments (Narrative) (Details) $ in Thousands	6 Months Ended
	Mar. 31, 2021USD ($)counterpartybblMMcf	Sep. 30, 2020USD ($)	Mar. 31, 2020USD ($)	Sep. 30, 2019USD ($)
Derivative Instruments, Gain (Loss) [Line Items]
Foreign Currency Forward Contract Hedge Duration	10 years
Net hedging gains (losses) in accumulated other comprehensive income (loss)	$ (17,100)
After tax net hedging gains (losses) in accumulated other comprehensive income (loss)	(12,100)
Pre-Tax Net Hedging Gains (Losses) Reclassified Within Twelve Months	(28,200)
After Tax Net Hedging Gains (Losses) Reclassified Within Twelve Months	(19,900)
Fair market value of derivative asset with a credit-risk related contingency	1,500
Fair market value of derivative liability with a credit-risk related contingency	21,200
Hedging collateral deposits	$ 0	$ 0	$ 10,728	$ 6,832
Cash Flow Hedges [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Hedge Duration	5 years
Over the Counter Swaps, No Cost Collars and Foreign Currency Forward Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Number of counterparties in which the company holds over-the-counter swap positions | counterparty	15
Number of counterparties in net gain position | counterparty	5
Credit risk exposure per counterparty	$ 800
Maximum credit risk exposure per counterparty	1,600
Collateral Received by the Company	0
Hedging collateral deposits	$ 0
Natural Gas MMCf [Member] | Cash Flow Hedges [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Nonmonetary notional amount of price risk cash flow hedge derivatives, natural gas | MMcf	253,300
Crude Oil Bbls [Member] | Cash Flow Hedges [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Nonmonetary notional amount of price risk cash flow hedge derivatives, crude oil | bbl	2,082,000
Foreign Currency Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Notional Amount	$ 69,400
Credit Risk Related Contingency Feature [Member] | Over the Counter Swaps, No Cost Collars and Foreign Currency Forward Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Number of counterparties with a common credit-risk related contingency | counterparty	13

Financial Instruments (Long-Ter

Financial Instruments (Long-Term Debt) (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Sep. 30, 2020
Financial Instruments, Owned, at Fair Value [Abstract]
Carrying Amount	$ 2,627,033	$ 2,629,576
Fair Value	$ 2,869,081	$ 2,778,556

Financial Investments (Other In

Financial Investments (Other Investments) (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Sep. 30, 2020
Investment Holdings [Line Items]
Life Insurance Contracts	$ 43,307	$ 41,992
Other Investments	147,421	154,502
Equity Mutual Fund [Member]
Investment Holdings [Line Items]
Fair Value	32,993	39,618
Fixed Income Mutual Fund [Member]
Investment Holdings [Line Items]
Fair Value	70,133	72,253
Marketable Equity Securities [Member]
Investment Holdings [Line Items]
Fair Value	$ 988	$ 639

Financial Instruments (Schedule

Financial Instruments (Schedule Of Derivative Financial Instruments Designated And Qualifying As Cash Flow Hedges On The Statement Of Financial Performance) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Derivative Gain or (Loss) Recognized in Other Comprehensive Income (Loss) on the Consolidated Statement of Comprehensive Income (Loss)	$ (34,373)	$ 76,304	$ 13,648	$ 76,799
Amount of Derivative Gain or (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) on the Consolidated Balance Sheet into the Consolidated Statement of Income	(3,666)	25,034	(3,977)	32,386
Foreign Currency Contracts [Member] | Operating Revenues [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Derivative Gain or (Loss) Recognized in Other Comprehensive Income (Loss) on the Consolidated Statement of Comprehensive Income (Loss)	750	(4,670)	3,176	(3,751)
Amount of Derivative Gain or (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) on the Consolidated Balance Sheet into the Consolidated Statement of Income	95	(271)	94	(462)
Commodity Contracts [Member] | Operating Revenues [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Derivative Gain or (Loss) Recognized in Other Comprehensive Income (Loss) on the Consolidated Statement of Comprehensive Income (Loss)	(35,123)	81,108	10,472	79,553
Amount of Derivative Gain or (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) on the Consolidated Balance Sheet into the Consolidated Statement of Income	(3,761)	23,396	(4,071)	30,937
Commodity Contracts [Member] | Purchased Gas [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Derivative Gain or (Loss) Recognized in Other Comprehensive Income (Loss) on the Consolidated Statement of Comprehensive Income (Loss)	0	(134)	0	997
Amount of Derivative Gain or (Loss) Reclassified from Accumulated Other Comprehensive Income (Loss) on the Consolidated Balance Sheet into the Consolidated Statement of Income	$ 0	$ 1,909	$ 0	$ 1,911

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020	Sep. 30, 2020	Sep. 30, 2018
Income Taxes [Line Items]
Effective Tax Rate	26.30%	(53.20%)	26.80%	139.90%
Valuation Allowance	$ 63.9	$ 56.8	$ 63.9	$ 56.8
First Installment of AMT Credit Refunds Received					$ 42.5
Accelerated AMT Credit Refund Received Under CARES Act					$ 42.5
Alternative Minimum Tax Credit [Member]
Income Taxes [Line Items]
Tax Credit Carryforwards						$ 85

Capitalization (Narrative) (Det

Capitalization (Narrative) (Details) - USD ($) $ in Thousands	Feb. 24, 2021	Mar. 31, 2021	Mar. 31, 2020	Mar. 11, 2021	Sep. 30, 2020
Debt Instrument [Line Items]
Shares tendered		82,936
Current Portion of Long-Term Debt		$ 0			$ 0
Net Proceeds from Issuance of Long-Term Debt		495,267	$ 0
Gain (Loss) on Extinguishment of Debt		(15,715)	$ 0
4.90% Notes Due December 1, 2021 [Member]
Debt Instrument [Line Items]
Long-Term Debt, face value				$ 500,000
Long-term debt, interest rate				4.90%
Debt Instrument, Redeemed		515,700
Gain (Loss) on Extinguishment of Debt		(15,700)
2.95% Notes Due March 1, 2031 [Member]
Debt Instrument [Line Items]
Long-Term Debt, face value	$ 500,000
Long-term debt, interest rate	2.95%
Net Proceeds from Issuance of Long-Term Debt	$ 495,300
Maximum interest rate adjustment	2.00%
Percentage of Principal Amount	101.00%
Fourth Amended & Restated Credit Agreement [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		750,000
364-Day Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		250,000
Line of Credit Facility, Original Maximum Borrowing Capacity		$ 200,000
Restricted Stock Units [Member]
Debt Instrument [Line Items]
Common stock issued		105,260
Performance Shares [Member]
Debt Instrument [Line Items]
Common stock issued		165,161
Board Of Directors [Member]
Debt Instrument [Line Items]
Common stock issued		21,616

Capitalization and Short-Term B

Capitalization and Short-Term Borrowings (Summary of Changes in Common Stock Equity) (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended		6 Months Ended
		Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020
Schedule of Capitalization, Equity [Line Items]
Beginning balance (shares)				90,954,696
Beginning balance				$ 1,004,158
Balance at Beginning of Period		$ 1,028,844	$ 1,320,592	991,630	$ 1,272,601
Balance at Beginning of Period		(79,741)	(56,150)	(114,757)	(52,155)
Net Income (Loss) Available for Common Stock		112,436	(106,068)	190,210	(19,477)
Dividends Declared on Common Stock		(40,562)	(37,654)	(81,122)	(75,304)
Other Comprehensive Income (Loss), Net of Tax		$ (22,247)	37,233	$ 12,769	33,238
Ending balance (shares)		91,163,797		91,163,797
Ending balance		$ 1,009,075		$ 1,009,075
Balance at March 31		1,100,718	1,176,870	1,100,718	1,176,870
Balance at End of Period		$ (101,988)	$ (18,917)	$ (101,988)	$ (18,917)
Dividends per share		$ 0.445	$ 0.435	$ 0.89	$ 0.87
Paid-in Capital [Member]
Schedule of Capitalization, Equity [Line Items]
Beginning balance		$ 1,004,369	$ 831,146	$ 1,004,158	$ 832,264
Share-Based Payment Expense	[1]	4,283	3,876	7,779	6,704
Common Stock Issued Under Stock and Benefit Plans		423	422
Stock Repurchased under Stock and Benefit Plans				(2,862)	(3,524)
Ending balance		1,009,075	835,444	1,009,075	835,444
Earnings Reinvested in The Business [Member]
Schedule of Capitalization, Equity [Line Items]
Balance at Beginning of Period		1,028,844	1,320,592	991,630	1,272,601
Net Income (Loss) Available for Common Stock		112,436	(106,068)	190,210	(19,477)
Dividends Declared on Common Stock		(40,562)	(37,654)	(81,122)	(75,304)
Balance at March 31		1,100,718	1,176,870	1,100,718	1,176,870
Accumulated Other Comprehensive Income (Loss) [Member]
Schedule of Capitalization, Equity [Line Items]
Balance at Beginning of Period		(79,741)	(56,150)	(114,757)	(52,155)
Other Comprehensive Income (Loss), Net of Tax		(22,247)	37,233	12,769	33,238
Balance at End of Period		$ (101,988)	$ (18,917)	$ (101,988)	$ (18,917)
Common Stock [Member]
Schedule of Capitalization, Equity [Line Items]
Beginning balance (shares)		91,153,000	86,552,000	90,955,000	86,315,000
Beginning balance (value)		$ 91,153	$ 86,552	$ 90,955	$ 86,315
Common Stock Issued Under Stock and Benefit Plans (Shares)		11,000	10,000	209,000	247,000
Common Stock Issued Under Stock and Benefit Plans		$ 11	$ 10	$ 209	$ 247
Ending balance (shares)		91,164,000	86,562,000	91,164,000	86,562,000
Ending balance (value)		$ 91,164	$ 86,562	$ 91,164	$ 86,562
Guidance for Hedging [Member] | Cumulative Effect of Adoption of Authoritative Guidance [Member]
Schedule of Capitalization, Equity [Line Items]
Balance at Beginning of Period		$ 0	$ 0	$ 0	(950)
Guidance for Hedging [Member] | Earnings Reinvested in The Business [Member] | Cumulative Effect of Adoption of Authoritative Guidance [Member]
Schedule of Capitalization, Equity [Line Items]
Balance at Beginning of Period					$ (950)
[1]	Paid in Capital includes compensation costs associated with performance shares and/or restricted stock awards. The expense is included within Net Income Available For Common Stock, net of tax benefits.

Commitments And Contingencies (

Commitments And Contingencies (Details) $ in Millions	6 Months Ended
	Mar. 31, 2021USD ($)
Site Contingency [Line Items]
Estimated minimum liability for environmental remediation	$ 3.3
Rate recovery period	1 year
Former Manufactured Gas Plant Site New York [Member]
Site Contingency [Line Items]
Estimated minimum liability for environmental remediation	$ 0.5

Business Segment Information (N

Business Segment Information (Narrative) (Details)	6 Months Ended
	Mar. 31, 2021segment
Segment Reporting [Abstract]
Number of reportable segments	4

Business Segment Information (F

Business Segment Information (Financial Segment Information By Segment) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020	Sep. 30, 2020
Segment Reporting Information [Line Items]
Revenue	$ 551,115	$ 491,095	$ 992,275	$ 935,283
Segment Profit: Net Income (Loss)	112,436	(106,068)	190,210	(19,477)
Segment Assets	7,115,652		7,115,652		$ 6,964,935
Revenue from External Customers [Member]
Segment Reporting Information [Line Items]
Revenue	551,115	491,095	992,275	935,283
Intersegment Revenues [Member]
Segment Reporting Information [Line Items]
Revenue	0	0	0	0
Exploration And Production [Member]
Segment Reporting Information [Line Items]
Revenue	220,187	155,560	411,582	321,499
Segment Profit: Net Income (Loss)	36,822	(175,275)	7,199	(151,299)
Segment Assets	2,023,147		2,023,147		1,979,028
Exploration And Production [Member] | Revenue from External Customers [Member]
Segment Reporting Information [Line Items]
Revenue	220,187	155,560	411,582	321,499
Exploration And Production [Member] | Intersegment Revenues [Member]
Segment Reporting Information [Line Items]
Revenue	0	0	0	0
Pipeline And Storage [Member]
Segment Reporting Information [Line Items]
Revenue	86,704	79,245	174,469	151,465
Segment Profit: Net Income (Loss)	24,928	22,087	49,112	40,192
Segment Assets	2,240,140		2,240,140		2,204,971
Pipeline And Storage [Member] | Revenue from External Customers [Member]
Segment Reporting Information [Line Items]
Revenue	59,314	51,919	118,623	100,888
Pipeline And Storage [Member] | Intersegment Revenues [Member]
Segment Reporting Information [Line Items]
Revenue	27,390	27,326	55,846	50,577
Gathering [Member]
Segment Reporting Information [Line Items]
Revenue	50,262	35,267	97,270	70,055
Segment Profit: Net Income (Loss)	20,700	19,898	41,250	35,842
Segment Assets	855,507		855,507		945,199
Gathering [Member] | Revenue from External Customers [Member]
Segment Reporting Information [Line Items]
Revenue	671	0	1,021	0
Gathering [Member] | Intersegment Revenues [Member]
Segment Reporting Information [Line Items]
Revenue	49,591	35,267	96,249	70,055
Utility [Member]
Segment Reporting Information [Line Items]
Revenue	270,881	254,493	459,881	451,318
Segment Profit: Net Income (Loss)	32,044	31,499	55,081	58,082
Segment Assets	2,151,304		2,151,304		2,067,852
Utility [Member] | Revenue from External Customers [Member]
Segment Reporting Information [Line Items]
Revenue	270,784	250,556	459,684	445,465
Utility [Member] | Intersegment Revenues [Member]
Segment Reporting Information [Line Items]
Revenue	97	3,937	197	5,853
Total Reportable Segments [Member]
Segment Reporting Information [Line Items]
Segment Profit: Net Income (Loss)	114,494	(101,791)	152,642	(17,183)
Segment Assets	7,270,098		7,270,098		7,197,050
Total Reportable Segments [Member] | Revenue from External Customers [Member]
Segment Reporting Information [Line Items]
Revenue	550,956	458,035	990,910	867,852
Total Reportable Segments [Member] | Intersegment Revenues [Member]
Segment Reporting Information [Line Items]
Revenue	77,078	66,530	152,292	126,485
All Other [Member]
Segment Reporting Information [Line Items]
Revenue	65	33,004	1,195	67,417
Segment Profit: Net Income (Loss)	(983)	1,169	36,577	1,540
Segment Assets	27,391		27,391		113,571
All Other [Member] | Revenue from External Customers [Member]
Segment Reporting Information [Line Items]
Revenue	64	32,925	1,175	67,161
All Other [Member] | Intersegment Revenues [Member]
Segment Reporting Information [Line Items]
Revenue	1	79	20	256
Corporate And Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue	(76,984)	(66,474)	(152,122)	(126,471)
Segment Profit: Net Income (Loss)	(1,075)	(5,446)	991	(3,834)
Segment Assets	(181,837)		(181,837)		$ (345,686)
Corporate And Intersegment Eliminations [Member] | Revenue from External Customers [Member]
Segment Reporting Information [Line Items]
Revenue	95	135	190	270
Corporate And Intersegment Eliminations [Member] | Intersegment Revenues [Member]
Segment Reporting Information [Line Items]
Revenue	$ (77,079)	$ (66,609)	$ (152,312)	$ (126,741)

Retirement Plan And Other Pos_3

Retirement Plan And Other Post-Retirement Benefits (Narrative) (Details) $ in Millions	6 Months Ended
	Mar. 31, 2021USD ($)
Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Company's contributions	$ 14.6
VEBA Trusts [Member]
Defined Benefit Plan Disclosure [Line Items]
Company's contributions	2.1
Minimum [Member] | Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Estimated future contributions in remainder of fiscal year	5
Minimum [Member] | VEBA Trusts [Member]
Defined Benefit Plan Disclosure [Line Items]
Estimated future contributions in remainder of fiscal year	0.5
Maximum [Member] | Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Estimated future contributions in remainder of fiscal year	10
Maximum [Member] | VEBA Trusts [Member]
Defined Benefit Plan Disclosure [Line Items]
Estimated future contributions in remainder of fiscal year	$ 1

Retirement Plan And Other Pos_4

Retirement Plan And Other Post-Retirement Benefits (Components Of Net Periodic Benefit Cost) (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020
Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service Cost		$ 2,466	$ 2,330	$ 4,932	$ 4,659
Interest Cost		5,422	7,483	10,843	14,965
Expected Return on Plan Assets		(14,537)	(15,016)	(29,074)	(30,032)
Amortization of Prior Service Cost (Credit)		158	182	316	365
Amortization of Losses		9,203	9,846	18,407	19,692
Net Amortization and Deferral For Regulatory Purposes (Including Volumetric Adjustments)	[1]	7,710	5,519	11,422	7,047
Net Periodic Benefit Cost		10,422	10,344	16,846	16,696
Other Post-Retirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service Cost		400	402	801	804
Interest Cost		2,326	3,228	4,652	6,457
Expected Return on Plan Assets		(7,241)	(7,308)	(14,482)	(14,616)
Amortization of Prior Service Cost (Credit)		(107)	(107)	(214)	(214)
Amortization of Losses		212	134	424	267
Net Amortization and Deferral For Regulatory Purposes (Including Volumetric Adjustments)	[1]	9,451	8,846	16,303	15,094
Net Periodic Benefit Cost		$ 5,041	$ 5,195	$ 7,484	$ 7,792
[1]	The Company’s policy is to record retirement plan and other post-retirement benefit costs in the Utility segment on a volumetric basis to reflect the fact that the Utility segment experiences higher throughput of natural gas in the winter months and lower throughput of natural gas in the summer months.

Regulatory Matters (Details)

Regulatory Matters (Details)	6 Months Ended
	Mar. 31, 2021
NEW YORK
Regulatory Matters [Line Items]
Approved Return on Equity	8.70%