Goodwill and Other Intangible Assets - Carrying Values of Goodwill Assigned to Partnership's Operating Segments (Details) - USD ($) $ in Thousands		12 Months Ended
		Sep. 26, 2020	Sep. 28, 2019
Goodwill [Line Items]
Goodwill		$ 1,110,243	$ 1,104,547
Accumulated adjustments		(6,462)	(6,462)
Goodwill, net		1,103,781	1,098,085
Goodwill acquired	[1]	5,696
Propane [Member]
Goodwill [Line Items]
Goodwill		1,091,443	1,085,747
Accumulated adjustments		0	0
Goodwill, net		1,091,443	1,085,747
Goodwill acquired	[1]	5,696
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).