Fair Value Measurements (Tables)

12 Months Ended

Sep. 30, 2022

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 September 30, 2022 and 2021. 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 have historically entered into both gas and oil swap agreements with the Company. 

	At Fair Value as of September 30, 2022
Recurring Fair Value Measures	Level 1		Level 2		Level 3		Netting Adjustments(1)		Total(1)
	(Dollars in thousands)
Assets:
Cash Equivalents — Money Market Mutual Funds	$	35,015	$	—	$	—	$	—	$	35,015
Hedging Collateral Deposits	91,670		—		—		—		91,670
Derivative Financial Instruments:
Over the Counter Swaps — Gas	—		5,177		—		(4,178)		999
Contingent Consideration for Asset Sale	—		8,176		—		—		8,176
Foreign Currency Contracts	—		128		—		(128)		—
Other Investments:
Balanced Equity Mutual Fund	19,506		—		—		—		19,506
Fixed Income Mutual Fund	33,348		—		—		—		33,348
Total	$	179,539	$	13,481	$	—	$	(4,306)	$	188,714
Liabilities:
Derivative Financial Instruments:
Over the Counter Swaps — Gas	$	—	$	517,464	$	—	$	(4,178)	$	513,286
Over the Counter No Cost Collars — Gas	—		270,453		—		—		270,453
Foreign Currency Contracts	—		2,048		—		(128)		1,920
Total	$	—	$	789,965	$	—	$	(4,306)	$	785,659
Total Net Assets/(Liabilities)	$	179,539	$	(776,484)	$	—	$	—	$	(596,945)

	At Fair Value as of September 30, 2021
Recurring Fair Value Measures	Level 1		Level 2		Level 3		Netting Adjustments(1)		Total(1)
	(Dollars in thousands)
Assets:
Cash Equivalents — Money Market Mutual Funds	$	22,269	$	—	$	—	$	—	$	22,269
Hedging Collateral Deposits	88,610		—		—		—		88,610
Derivative Financial Instruments:
Over the Counter Swaps — Gas and Oil	—		1,802		—		(1,802)		—
Foreign Currency Contracts	—		938		—		(938)		—
Other Investments:
Balanced Equity Mutual Fund	34,433		—		—		—		34,433
Fixed Income Mutual Fund	70,639		—		—		—		70,639
Total	$	215,951	$	2,740	$	—	$	(2,740)	$	215,951
Liabilities:
Derivative Financial Instruments:
Over the Counter Swaps — Gas and Oil	$	—	$	601,551	$	—	$	(1,802)	$	599,749
Over the Counter No Cost Collars — Gas	—		17,385		—		—		17,385
Foreign Currency Contracts	—		214		—		(938)		(724)
Total	$	—	$	619,150	$	—	$	(2,740)	$	616,410
Total Net Assets/(Liabilities)	$	215,951	$	(616,410)	$	—	$	—	$	(400,459)

(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.