Selected Balance Sheet Information - Property Plant and Equipment (Details) - USD ($) $ in Thousands	Sep. 26, 2015	Sep. 27, 2014
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	$ 1,360,806	$ 1,356,746
Less: accumulated depreciation	(579,748)	(529,920)
Property, plant and equipment, net	781,058	826,826
Land and improvements [Member]
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	195,430	201,353
Buildings and improvements [Member]
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	104,998	103,751
Transportation equipment [Member]
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	58,650	64,254
Storage facilities [Member]
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	110,033	110,586
Equipment, primarily tanks and cylinders [Member]
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	833,479	823,478
Computer systems [Member]
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	51,039	49,904
Construction in progress [Member]
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	$ 7,177	$ 3,420