Segment Information - Disclosure by Reportable Segment and Reconciliation of Total Operating Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 28, 2020	Mar. 30, 2019	Mar. 28, 2020	Mar. 30, 2019	Sep. 28, 2019
Revenues [Abstract]
Total revenues	$ 401,055	$ 504,377	$ 734,933	$ 881,481
Operating income:
Total operating income	97,625	142,090	157,479	190,624
Reconciliation to net income:
Loss on debt extinguishment	109	0	109	0
Interest expense, net	19,176	19,647	38,248	39,135
Other, net	979	1,175	1,957	2,351
(Benefit from) provision for income taxes	0	252	(359)	403
Net income	77,361	121,016	117,524	148,735
Depreciation and amortization [Abstract]
Total depreciation and amortization	29,288	30,623	58,562	60,694
Assets [Abstract]
Total assets	2,160,017		2,160,017		$ 1,998,348
Operating/Reportable Segments [Member] | Propane [Member]
Revenues [Abstract]
Total revenues	347,686	433,056	633,111	754,416
Operating income:
Total operating income	115,143	162,650	201,265	233,121
Depreciation and amortization [Abstract]
Total depreciation and amortization	26,871	27,939	53,851	54,894
Assets [Abstract]
Total assets	2,031,125		2,031,125		1,904,344
Operating/Reportable Segments [Member] | Fuel Oil and Refined Fuels [Member]
Revenues [Abstract]
Total revenues	31,502	41,598	57,393	70,507
Operating income:
Total operating income	6,391	8,071	9,119	11,541
Depreciation and amortization [Abstract]
Total depreciation and amortization	468	503	975	1,025
Assets [Abstract]
Total assets	54,635		54,635		44,279
Operating/Reportable Segments [Member] | Natural Gas and Electricity [Member]
Revenues [Abstract]
Total revenues	10,198	17,596	18,919	31,000
Operating income:
Total operating income	2,778	4,885	5,007	7,713
Depreciation and amortization [Abstract]
Total depreciation and amortization	6	0	6	0
Assets [Abstract]
Total assets	12,341		12,341		11,907
Operating/Reportable Segments [Member] | All Other [Member]
Revenues [Abstract]
Total revenues	11,669	12,127	25,510	25,558
Operating income:
Total operating income	(4,846)	(4,152)	(10,233)	(8,796)
Depreciation and amortization [Abstract]
Total depreciation and amortization	48	48	95	100
Assets [Abstract]
Total assets	16,479		16,479		2,950
Operating/Reportable Segments [Member] | Corporate [Member]
Operating income:
Total operating income	(21,841)	(29,364)	(47,679)	(52,955)
Depreciation and amortization [Abstract]
Total depreciation and amortization	1,895	$ 2,133	3,635	$ 4,675
Assets [Abstract]
Total assets	$ 45,437		$ 45,437		$ 34,868