Acquisitions (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2014	Sep. 26, 2015	Sep. 27, 2014	Apr. 30, 2014	Dec. 31, 2013
Acquisitions [Line Items]
Goodwill	$ 340,743	$ 341,305	$ 336,252		$ 12,274
ATMI [Member]
Acquisitions [Line Items]
Property, plant, and equipment				$ 124,025
Identifiable intangible assets				297,040
Acquisition date	Apr. 30, 2014
Goodwill				337,095
Payments to Acquire Businesses, Gross	$ 1,130,484
Total purchase price, net of cash acquired				$ 809,390