Long-Term Borrowings - Additional Information (Details) $ in Thousands		3 Months Ended		9 Months Ended	12 Months Ended
	Dec. 28, 2022 USD ($)	Dec. 27, 2025 USD ($)	Dec. 28, 2024 USD ($)	Jun. 28, 2025	Sep. 27, 2025 USD ($)	Mar. 15, 2024 USD ($)
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	$ 80,645	$ 1,334,694			$ 1,218,892
Loss on debt extinguishment		(1,183)	$ 0
Consolidated fixed charge coverage ratio, minimum				1.75
Long-term debt maturities, 2026		0
Long-term debt maturities, 2027		0
Long-term debt maturities, 2028		0
Long-term debt maturities, 2029		276,307
Long-term debt maturities, 2030		12,352
Long-term debt maturities, thereafter		$ 1,056,586
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)		6.27%
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%
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Maturity date		Mar. 15, 2029
Long-term borrowings		$ 264,600			149,200
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		$ 23,886
Standby letters of credit issued under the Revolving Credit Facility, expiration date		Nov. 21, 2026
Revolving Credit Facility [Member] \| Third Amended and Restated Credit [Member]
Debt Instrument [Line Items]
Long-term borrowings					$ 149,200
Revolving Credit Facility [Member] \| Fourth Amended And Restated Credit Agreement [Member]
Debt Instrument [Line Items]
Maturity date		Mar. 15, 2029
Long-term borrowings		$ 264,600
Credit Facility, maximum amount						$ 500,000
Green Bonds [Member]
Debt Instrument [Line Items]
Debt service coverage ratio minimum	1
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
6.50% Senior Notes due December 15, 2035 [Member]
Debt Instrument [Line Items]
Stated interest rate (in hundredths)		6.50%			6.50%
Maturity date		Dec. 15, 2035			Dec. 15, 2035
Date public offering completed		Dec. 22, 2025
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		$ 350,000
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]
Debt Instrument [Line Items]
Loss on debt extinguishment		$ 1,183
Senior notes redemption aggregate price		106.50%
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		$ 0			$ 350,000
Percentage of principal amount at which debt was issued (in hundredths)		100.00%
Aggregate principal amount		$ 350,000
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
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
Senior Notes [Member] \| 6.50% Senior Notes due December 15, 2035 [Member]
Debt Instrument [Line Items]
Long-term borrowings		$ 350,000			$ 0

SUBURBAN PROPANE PARTNERS LP 10-Q