Goodwill and Other Intangible Assets - Carrying Values of Goodwill Assigned to Partnership's Operating Segments (Details) - USD ($) $ in Thousands		6 Months Ended
		Mar. 25, 2023	Sep. 24, 2022
Goodwill [Line Items]
Goodwill		$ 1,151,644	$ 1,119,885
Accumulated adjustments		(6,462)	(6,462)
Goodwill, net		1,145,182	1,113,423
Goodwill acquired	[1]	31,759
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
Propane [Member]
Goodwill [Line Items]
Goodwill		1,101,085	1,101,085
Accumulated adjustments		0	0
Goodwill, net		1,101,085	1,101,085
Goodwill acquired	[1]	0
All Other [Member]
Goodwill [Line Items]
Goodwill		31,759	0
Accumulated adjustments		0	0
Goodwill, net		31,759	$ 0
Goodwill acquired	[1]	$ 31,759

[1] (1) Reflects the impact of the acquisition; see Note 4, “Investments in and Acquisitions of Businesses.”