Segment Information - Disclosure by Reportable Segment and Reconciliation of Total Operating Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 26, 2022	Mar. 27, 2021	Mar. 26, 2022	Mar. 27, 2021	Sep. 25, 2021
Revenues [Abstract]
Total revenues	$ 588,095	$ 537,238	$ 963,502	$ 842,429
Operating income (loss):
Total operating income	191,961	147,157	229,217	204,843
Reconciliation to net income:
Interest expense, net	15,254	18,092	30,553	36,227
Other, net	1,234	1,582	2,364	2,660
Provision for income taxes	371	267	(100)	763
Net income	175,102	127,216	196,400	165,193
Depreciation and amortization [Abstract]
Total depreciation and amortization	14,062	27,346	30,347	55,363
Assets [Abstract]
Total assets	2,199,857		2,199,857		$ 2,051,730
Operating/Reportable Segments [Member] | Propane [Member]
Revenues [Abstract]
Total revenues	516,821	481,328	847,938	749,952
Operating income (loss):
Total operating income	221,386	172,090	287,961	255,695
Depreciation and amortization [Abstract]
Total depreciation and amortization	11,764	24,988	25,498	50,679
Assets [Abstract]
Total assets	2,031,431		2,031,431		1,935,399
Operating/Reportable Segments [Member] | Fuel Oil and Refined Fuels [Member]
Revenues [Abstract]
Total revenues	43,501	32,011	64,467	47,761
Operating income (loss):
Total operating income	7,185	7,608	8,879	10,233
Depreciation and amortization [Abstract]
Total depreciation and amortization	428	396	856	796
Assets [Abstract]
Total assets	59,301		59,301		47,039
Operating/Reportable Segments [Member] | Natural Gas and Electricity [Member]
Revenues [Abstract]
Total revenues	14,395	10,750	23,618	17,626
Operating income (loss):
Total operating income	3,450	3,404	5,120	5,363
Depreciation and amortization [Abstract]
Total depreciation and amortization	5	6	10	12
Assets [Abstract]
Total assets	13,241		13,241		11,275
Operating/Reportable Segments [Member] | All Other [Member]
Revenues [Abstract]
Total revenues	13,378	13,149	27,479	27,090
Operating income (loss):
Total operating income	(5,002)	(4,232)	(10,792)	(9,293)
Depreciation and amortization [Abstract]
Total depreciation and amortization	45	47	90	94
Assets [Abstract]
Total assets	48,859		48,859		17,767
Operating/Reportable Segments [Member] | Corporate [Member]
Operating income (loss):
Total operating income	(35,058)	(31,713)	(61,951)	(57,155)
Depreciation and amortization [Abstract]
Total depreciation and amortization	1,820	$ 1,909	3,893	$ 3,782
Assets [Abstract]
Total assets	$ 47,025		$ 47,025		$ 40,250