Segment Information - Disclosure by Reportable Segment and Reconciliation of Total Operating Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Jun. 26, 2021	Jun. 27, 2020	Jun. 27, 2020	Jun. 26, 2021	Jun. 27, 2020	Jun. 27, 2020	Sep. 26, 2020
Revenues [Abstract]
Total revenues	$ 238,085		$ 206,906	$ 1,080,514	$ 941,839
Operating income (loss):
Total operating income	8,003		4,880	212,846	162,359
Reconciliation to net (loss) income:
Loss on debt extinguishment	16,029		0	16,029	109
Interest expense, net	16,737		18,474	52,964	56,722
Other, net	1,085		1,878	3,745	3,835
Provision for (benefit from) income taxes	173		106	936	(253)
Net (loss) income	(26,021)	$ (15,578)	(15,578)	139,172	101,946	$ 101,946
Depreciation and amortization [Abstract]
Total depreciation and amortization	27,254		29,153	82,617	87,715
Assets [Abstract]
Total assets	2,046,762			2,046,762			$ 2,047,253
Operating/Reportable Segments [Member] | Propane [Member]
Revenues [Abstract]
Total revenues	208,689		179,049	958,641	812,160
Operating income (loss):
Total operating income	41,460		32,074	297,155	233,339
Depreciation and amortization [Abstract]
Total depreciation and amortization	25,083		26,724	75,762	80,575
Assets [Abstract]
Total assets	1,924,514			1,924,514			1,934,960
Operating/Reportable Segments [Member] | Fuel Oil and Refined Fuels [Member]
Revenues [Abstract]
Total revenues	11,314		11,702	59,075	69,095
Operating income (loss):
Total operating income	(433)		1,078	9,800	10,197
Depreciation and amortization [Abstract]
Total depreciation and amortization	429		451	1,225	1,426
Assets [Abstract]
Total assets	48,381			48,381			47,063
Operating/Reportable Segments [Member] | Natural Gas and Electricity [Member]
Revenues [Abstract]
Total revenues	5,835		6,099	23,461	25,018
Operating income (loss):
Total operating income	1,103		1,742	6,466	6,749
Depreciation and amortization [Abstract]
Total depreciation and amortization	6		6	18	12
Assets [Abstract]
Total assets	10,794			10,794			10,594
Operating/Reportable Segments [Member] | All Other [Member]
Revenues [Abstract]
Total revenues	12,247		10,056	39,337	35,566
Operating income (loss):
Total operating income	(5,117)		(5,053)	(14,410)	(15,286)
Depreciation and amortization [Abstract]
Total depreciation and amortization	47		47	141	142
Assets [Abstract]
Total assets	18,594			18,594			18,733
Operating/Reportable Segments [Member] | Corporate [Member]
Operating income (loss):
Total operating income	(29,010)		(24,961)	(86,165)	(72,640)
Depreciation and amortization [Abstract]
Total depreciation and amortization	1,689		$ 1,925	5,471	$ 5,560
Assets [Abstract]
Total assets	$ 44,479			$ 44,479			$ 35,903