Fair Value Measurements (Tables)

12 Months Ended

Sep. 30, 2023

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, 2023 and 2022. Financial assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement.

	At Fair Value as of September 30, 2023
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	$	39,332	$	—	$	—	$	—	$	39,332
Derivative Financial Instruments:
Over the Counter Swaps — Gas	—		65,800		—		(37,508)		28,292
Over the Counter No Cost Collars — Gas	—		30,966		—		(14,745)		16,221
Contingent Consideration for Asset Sale	—		7,277		—		—		7,277
Foreign Currency Contracts	—		150		—		(1,453)		(1,303)
Other Investments:
Balanced Equity Mutual Fund	15,837		—		—		—		15,837
Fixed Income Mutual Fund	15,897		—		—		—		15,897
Total	$	71,066	$	104,193	$	—	$	(53,706)	$	121,553
Liabilities:
Derivative Financial Instruments:
Over the Counter Swaps — Gas	$	—	$	68,311	$	—	$	(37,508)	$	30,803
Over the Counter No Cost Collars — Gas	—		14,950		—		(14,745)		205
Foreign Currency Contracts	—		1,454		—		(1,453)		1
Total	$	—	$	84,715	$	—	$	(53,706)	$	31,009
Total Net Assets/(Liabilities)	$	71,066	$	19,478	$	—	$	—	$	90,544

	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)

(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.