Long-Term Debt and Bank Facility Borrowings - Additional Information (Detail)				1 Months Ended	3 Months Ended		4 Months Ended	7 Months Ended	9 Months Ended
		Sep. 30, 2023 USD ($)	Jul. 06, 2022 USD ($)	Oct. 30, 2023	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Feb. 27, 2024	Sep. 30, 2024	Jun. 30, 2024 USD ($)	Jun. 30, 2023 USD ($)
Debt Instrument [Line Items]
Additional loan repayments									$ 12,250,000	$ 12,375,000
Fixed charge coverage ratio					1.39
Hedging positions and payable amounts secured under credit facility		$ 100,000							2,900,000
Letters of credit issued and outstanding		3,200,000							5,700,000
Long-term debt, fair value	[1]	148,740,000							136,521,000
Revolving credit facility outstanding		240,000							4,396,000
Availability under credit agreement		$ 202,100,000							$ 201,000,000
Term Loan
Debt Instrument [Line Items]
Debt instrument, effective interest rate		6.60%							7.20%
Long-term debt, fair value	[1],[2]	$ 148,500,000							$ 132,125,000
Revolving Credit Facility
Debt Instrument [Line Items]
Debt instrument, effective interest rate		6.30%							7.50%
Revolving credit facility outstanding		$ 200,000							$ 4,400,000
Credit Agreement
Debt Instrument [Line Items]
Non Seasonal maximum borrowing capacity under revolving credit facility			$ 400,000,000
Maximum borrowing capacity (heating season December to April) under revolving credit facility			550,000,000
Issuance of line of credit for working capital purposes			$ 25,000,000
Senior secured term loan maturity date			Jul. 06, 2027
Facility size that can be increased additional without consulting bank group									200,000,000
Facility size that can be increased without consulting bank group									200,000,000
Term loan annual payment percentage			25.00%
Additional loan repayments					$ 4,000,000.0	$ 0
Commitment fee on the unused portion of the facility from December through April			0.30%
Commitment fee on the unused portion of the facility from May through November			0.20%
Minimum fixed charge coverage ratio			110.00%
Availability percentage to maximum facility size		12.50%	12.50%
Minimum fixed charge coverage ratio to be maintained credit facilities				110.00%			100.00%
Credit Agreement | Maximum
Debt Instrument [Line Items]
Senior secured leverage ratio during quarters ending June or September			300.00%
Senior secured leverage ratio during quarters ending December or March			550.00%
Credit Agreement | Quarterly
Debt Instrument [Line Items]
Term loan periodic payment			$ 4,100,000
Credit Agreement | Annually | Maximum
Debt Instrument [Line Items]
Term loan periodic payment									$ 8,500,000
Credit Agreement | Term Loan
Debt Instrument [Line Items]
Outstanding term loan			$ 165,000,000
Senior secured term loan maturity period			5 years
Sixth Amendment
Debt Instrument [Line Items]
Non Seasonal maximum borrowing capacity under revolving credit facility			$ 400,000,000
Maximum borrowing capacity (heating season December to April) under revolving credit facility			$ 550,000,000
Minimum fixed charge coverage ratio for distributions to unit holders or to repurchase common units			100.00%	115.00%			100.00%
Sixth Amendment | Scenario Forecast
Debt Instrument [Line Items]
Minimum fixed charge coverage ratio for distributions to unit holders or to repurchase common units								115.00%
Sixth Amendment | Term Loan
Debt Instrument [Line Items]
Outstanding term loan			$ 165,000,000
Senior secured term loan maturity period			5 years

[1] The face amount of the Company’s variable rate long-term debt approximates fair value.

[2] Carrying amounts are net of unamortized debt issuance costs of $0.5 million as of June 30, 2024 and $0.7 million as of September 30, 2023