Long-Term Borrowings - Additional Information (Details) - USD ($) $ in Thousands		12 Months Ended
	Mar. 05, 2020	Sep. 30, 2023	Sep. 24, 2022	Sep. 25, 2021	Dec. 28, 2022
Debt Instrument [Line Items]
Ownership interest in Suburban Energy Finance Corp (in hundredths)		100.00%
Stated interest rate (in hundredths)					5.50%
Long-term borrowings		$ 1,198,766	$ 1,089,600		$ 80,645
Loss on debt extinguishment		$ 0	0	$ 16,029
Consolidated fixed charge coverage ratio, minimum		1.75
Capitalized costs		$ 2,717
Long-term debt maturities, 2024		0
Long-term debt maturities, 2025		132,000
Long-term debt maturities, 2026		0
Long-term debt maturities, 2027		350,000
Long-term debt maturities, 2028		0
Long-term debt maturities, 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%
Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Debt Instrument [Line Items]
Description of applicable interest rate on borrowings		SOFR
Margin over basis rate (in hundredths)		1.00%
Amended Revolving Credit Facility Due2025 [Member]
Debt Instrument [Line Items]
Margin over basis rate (in hundredths)		1.00%
Weighted average interest rate (in hundredths)		7.91%
Amended Revolving Credit Facility Due2025 [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%
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Long-term borrowings		$ 132,000	89,600
Maturity date	Mar. 05, 2025	Mar. 05, 2025
Write-off unamortized debt origination costs		$ 109
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		$ 42,736
Standby letters of credit issued under the Revolving Credit Facility, expiration date		Apr. 30, 2024
Revolving Credit Facility [Member] | Third Amended and Restated Credit [Member]
Debt Instrument [Line Items]
Long-term borrowings		$ 132,000	89,600
Credit Facility, maximum amount	$ 500,000
Capitalized debt origination costs		$ 903	$ 1,312
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
5.0% Senior Notes due June 1, 2031 [Member]
Debt Instrument [Line Items]
Ownership interest in Suburban Energy Finance Corp (in hundredths)		100.00%
Stated interest rate (in hundredths)		5.00%	5.00%
Date public offering completed		May 24, 2021
Percentage of principal amount at which debt was issued (in hundredths)		100.00%
Maturity date		Jun. 01, 2031
Aggregate principal amount		$ 650,000
Debt instrument interest redemption percentage		35.00%
Redemption prices percentage		105.00%
Senior Notes Due2024 [Member]
Debt Instrument [Line Items]
Stated interest rate (in hundredths)		5.50%
Senior Notes Due2025 [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]
Ownership interest in Suburban Energy Finance Corp (in hundredths)		100.00%
Stated interest rate (in hundredths)		5.875%
Date public offering completed		Feb. 14, 2017
Long-term borrowings		$ 350,000	$ 350,000
Percentage of principal amount at which debt was issued (in hundredths)		100.00%
Maturity date		Mar. 01, 2027
Aggregate principal amount		$ 350,000
Redemption start date		Mar. 01, 2022
Redemption description		The 2027 Senior Notes are redeemable, at the Partnership’s option, in whole or in part, at any time on or after March 1, 2022, in each case at the redemption prices described in the table below, together with any accrued and unpaid interest to the date of the redemption.
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] | 5.0% 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