Segment Information - Disclosure by Reportable Segment and Reconciliation of Total Operating Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 30, 2019	Mar. 31, 2018	Mar. 30, 2019	Mar. 31, 2018	Sep. 29, 2018
Revenues [Abstract]
Total revenues	$ 504,377	$ 536,282	$ 881,481	$ 909,559
Operating income:
Total operating income (loss)	142,090	127,404	190,624	184,324
Reconciliation to net income:
Interest expense, net	19,647	19,402	39,135	38,916
Other, net	1,175	1,174	2,351	2,346
Provision for (benefit from) income taxes	252	41	403	(893)
Net income	121,016	106,787	148,735	143,955
Depreciation and amortization [Abstract]
Total depreciation and amortization	30,623	32,203	60,694	63,334
Assets [Abstract]
Total assets	2,139,970		2,139,970		$ 2,101,199
Operating/Reportable Segments [Member] | Propane [Member]
Revenues [Abstract]
Total revenues	433,056	462,814	754,416	784,944
Operating income:
Total operating income (loss)	162,650	144,395	233,121	220,118
Depreciation and amortization [Abstract]
Total depreciation and amortization	27,939	28,288	54,894	56,069
Assets [Abstract]
Total assets	2,020,044		2,020,044		1,995,060
Operating/Reportable Segments [Member] | Fuel Oil and Refined Fuels [Member]
Revenues [Abstract]
Total revenues	41,598	41,699	70,507	67,014
Operating income:
Total operating income (loss)	8,071	7,199	11,541	11,023
Depreciation and amortization [Abstract]
Total depreciation and amortization	503	716	1,025	1,295
Assets [Abstract]
Total assets	55,396		55,396		47,911
Operating/Reportable Segments [Member] | Natural Gas and Electricity [Member]
Revenues [Abstract]
Total revenues	17,596	20,392	31,000	33,539
Operating income:
Total operating income (loss)	4,885	5,454	7,713	8,939
Depreciation and amortization [Abstract]
Total depreciation and amortization	0	0	0	0
Assets [Abstract]
Total assets	15,277		15,277		13,067
Operating/Reportable Segments [Member] | All Other [Member]
Revenues [Abstract]
Total revenues	12,127	11,377	25,558	24,062
Operating income:
Total operating income (loss)	(4,152)	(4,981)	(8,796)	(10,214)
Depreciation and amortization [Abstract]
Total depreciation and amortization	48	56	100	106
Assets [Abstract]
Total assets	3,649		3,649		3,363
Operating/Reportable Segments [Member] | Corporate [Member]
Operating income:
Total operating income (loss)	(29,364)	(24,663)	(52,955)	(45,542)
Depreciation and amortization [Abstract]
Total depreciation and amortization	2,133	$ 3,143	4,675	$ 5,864
Assets [Abstract]
Total assets	$ 45,604		$ 45,604		$ 41,798