Goodwill and Other Intangible Assets - Carrying Values of Goodwill Assigned to Partnership's Operating Segments (Details) - USD ($) $ in Thousands		9 Months Ended
		Jun. 26, 2021	Sep. 26, 2020
Goodwill [Line Items]
Goodwill		$ 1,113,488	$ 1,110,243
Accumulated adjustments		(6,462)	(6,462)
Goodwill, net		1,107,026	1,103,781
Goodwill acquired	[1]	3,245
Propane [Member]
Goodwill [Line Items]
Goodwill		1,094,688	1,091,443
Accumulated adjustments		0	0
Goodwill, net		1,094,688	1,091,443
Goodwill acquired	[1]	3,245
Fuel Oil and Refined Fuels [Member]
Goodwill [Line Items]
Goodwill		10,900	10,900
Accumulated adjustments		(6,462)	(6,462)
Goodwill, net		4,438	4,438
Goodwill acquired	[1]	0
Natural Gas and Electricity [Member]
Goodwill [Line Items]
Goodwill		7,900	7,900
Accumulated adjustments		0	0
Goodwill, net		7,900	$ 7,900
Goodwill acquired	[1]	$ 0

[1] Reflects the impact from acquisitions (See Note 4).