Selected Balance Sheet Information - Property Plant and Equipment (Details) - USD ($) $ in Thousands	Sep. 24, 2016	Sep. 26, 2015
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	$ 1,373,028	$ 1,360,806
Less: accumulated depreciation	(630,899)	(579,748)
Property, plant and equipment, net	742,129	781,058
Land and improvements [Member]
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	193,194	195,430
Buildings and improvements [Member]
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	109,345	104,998
Transportation equipment [Member]
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	57,823	58,650
Storage facilities [Member]
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	110,528	110,033
Equipment, primarily tanks and cylinders [Member]
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	845,650	833,479
Computer systems [Member]
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	52,643	51,039
Construction in progress [Member]
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	$ 3,845	$ 7,177