Long-Term Borrowings - Additional Information (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Mar. 30, 2024	Sep. 30, 2023	Mar. 15, 2024	Dec. 28, 2022
Debt Instrument [Line Items]
Stated interest rate (in hundredths)				5.50%
Ownership interest in Suburban Energy Finance Corp (in hundredths)	100.00%
Long-term borrowings	$ 1,221,951	$ 1,198,766		$ 80,645
Standby letters of credit issued under the Revolving Credit Facility, expiration date	Mar. 15, 2025
Consolidated fixed charge coverage ratio, minimum	1.75
Long-term debt maturities, 2024	$ 0
Long-term debt maturities, 2025	0
Long-term debt maturities, 2026	0
Long-term debt maturities, 2027	504,500
Long-term debt maturities, 2028	0
Long-term debt maturities, 2028 and thereafter	$ 730,645
Federal Funds Rate [Member]
Debt Instrument [Line Items]
Description of applicable interest rate on borrowings	Federal Funds Rate
Margin over basis rate (in hundredths)	0.50%
Amended Credit Agreement Due 2025 [Member]
Debt Instrument [Line Items]
Margin over basis rate (in hundredths)	1.00%
Weighted average interest rate (in hundredths)	7.74%
Amended Credit Agreement Due 2025 [Member] | Federal Funds Rate [Member]
Debt Instrument [Line Items]
Description of applicable interest rate on borrowings	Federal Funds Rate
Margin over basis rate (in hundredths)	0.50%
Fourth Amended And Restated Credit Agreement [Member]
Debt Instrument [Line Items]
Deferred Debt Issuance Cost, Writeoff	$ 215
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Maturity date	Mar. 15, 2029
Long-term borrowings	$ 154,500	132,000
Consolidated interest coverage ratio, minimum	2.5
Total consolidated leverage ratio	5.75
Senior secured unconsolidated leverage ratio maximum	3.25
Standby letters of credit issued under the Revolving Credit Facility	$ 33,586
Revolving Credit Facility [Member] | Third Amended and Restated Credit [Member]
Debt Instrument [Line Items]
Long-term borrowings	$ 187,900	$ 132,000
Revolving Credit Facility [Member] | Fourth Amended And Restated Credit Agreement [Member]
Debt Instrument [Line Items]
Maturity date	Mar. 15, 2029
Long-term borrowings	$ 154,500
Credit Facility, maximum amount			$ 500,000
5.875% Senior Notes due March 1, 2027 [Member]
Debt Instrument [Line Items]
Stated interest rate (in hundredths)	5.875%	5.875%
Maturity date	Mar. 01, 2027	Mar. 01, 2027
5.00% Senior Notes due June 1, 2031 [Member]
Debt Instrument [Line Items]
Stated interest rate (in hundredths)	5.00%	5.00%
Maturity date	Jun. 01, 2031	Jun. 01, 2031
Date public offering completed	May 24, 2021
Ownership interest in Suburban Energy Finance Corp (in hundredths)	100.00%
Percentage of principal amount at which debt was issued (in hundredths)	100.00%
Aggregate principal amount	$ 650,000
5.5% Senior Notes due June 1, 2024 [Member]
Debt Instrument [Line Items]
Stated interest rate (in hundredths)	5.50%
5.75% Senior Notes due March 1, 2025 [Member]
Debt Instrument [Line Items]
Stated interest rate (in hundredths)	5.75%
Senior Notes [Member] | 5.875% Senior Notes due March 1, 2027 [Member]
Debt Instrument [Line Items]
Stated interest rate (in hundredths)	5.875%
Maturity date	Mar. 01, 2027
Date public offering completed	Feb. 14, 2017
Ownership interest in Suburban Energy Finance Corp (in hundredths)	100.00%
Long-term borrowings	$ 350,000	$ 350,000
Percentage of principal amount at which debt was issued (in hundredths)	100.00%
Percentage of the principal amount repurchase offer under change of control provision (in hundredths)	101.00%
Repurchase of debt due to decline in rating after consummation of change of control, period	90 days
Senior Notes [Member] | 7.375% Senior Notes due August 1, 2021 [Member]
Debt Instrument [Line Items]
Stated interest rate (in hundredths)	7.375%
Senior Notes [Member] | 5.00% Senior Notes due June 1, 2031 [Member]
Debt Instrument [Line Items]
Long-term borrowings	$ 650,000	$ 650,000
Percentage of the principal amount repurchase offer under change of control provision (in hundredths)	101.00%
Repurchase of debt due to decline in rating after consummation of change of control, period	90 days