Segment Information - Disclosure by Reportable Segment and Reconciliation of Total Operating Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 24, 2016	Dec. 26, 2015	Sep. 24, 2016
Revenues [Abstract]
Total revenues	$ 317,307	$ 275,857
Operating income [Abstract]:
Total operating income	53,485	31,344
Reconciliation to net income:
Interest expense, net	18,831	18,893
Provision for income taxes	165	185
Net income	34,489	12,266
Depreciation and amortization [Abstract]
Total depreciation and amortization	31,261	31,638
Assets [Abstract]
Total assets	2,294,225		$ 2,282,299
Operating/Reportable Segments [Member] | Propane [Member]
Revenues [Abstract]
Total revenues	269,459	231,475
Operating income [Abstract]:
Total operating income	74,663	55,583
Depreciation and amortization [Abstract]
Total depreciation and amortization	27,384	27,107
Assets [Abstract]
Total assets	2,170,284		2,141,108
Operating/Reportable Segments [Member] | Fuel Oil and Refined Fuels [Member]
Revenues [Abstract]
Total revenues	22,096	20,688
Operating income [Abstract]:
Total operating income	2,848	1,969
Depreciation and amortization [Abstract]
Total depreciation and amortization	631	696
Assets [Abstract]
Total assets	58,901		53,266
Operating/Reportable Segments [Member] | Natural Gas and Electricity [Member]
Revenues [Abstract]
Total revenues	13,067	11,674
Operating income [Abstract]:
Total operating income	3,120	2,252
Depreciation and amortization [Abstract]
Total depreciation and amortization	0	2
Assets [Abstract]
Total assets	15,614		13,415
Operating/Reportable Segments [Member] | All Other [Member]
Revenues [Abstract]
Total revenues	12,685	12,020
Operating income [Abstract]:
Total operating income	(5,206)	(7,056)
Depreciation and amortization [Abstract]
Total depreciation and amortization	70	82
Assets [Abstract]
Total assets	2,666		2,185
Operating/Reportable Segments [Member] | Corporate [Member]
Operating income [Abstract]:
Total operating income	(21,940)	(21,404)
Depreciation and amortization [Abstract]
Total depreciation and amortization	3,176	$ 3,751
Assets [Abstract]
Total assets	$ 46,760		$ 72,325