Investment in and Acquisition and Disposition of Businesses - Summary of Acquisition and Purchase Price Allocation (Details) - USD ($) $ in Thousands		12 Months Ended
		Sep. 26, 2020	Sep. 28, 2019	Sep. 29, 2018
Georgia and California [Member]
Business Acquisition And Dispositions [Line Items]
Business acquisition, cost of acquired, cash paid	[1],[2]	$ 27,065
Texas, Florida and West Coast [Member]
Business Acquisition And Dispositions [Line Items]
Business acquisition, cost of acquired, cash paid	[1],[3]		$ 22,850
Florida and California [Member]
Business Acquisition And Dispositions [Line Items]
Business acquisition, cost of acquired, cash paid	[1],[4]			$ 16,771

[1] Total consideration includes non-compete consideration, which will be paid over the respective non-compete periods subject to compliance with the terms of the respective agreements, and excludes working capital adjustments.

[2] Includes the investment in Oberon and two acquisitions of propane retailers located in Georgia and California.

[3] Includes three acquisitions of propane retailers located in Texas, Florida and the West Coast.  Total consideration includes the issuance of $1,600 in Common Units.

[4] Includes two acquisitions of propane retailers located in Florida and California.