Purchase Price (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Apr. 30, 2014
Acquisitions [Line Items]
Payments to Acquire Businesses, Net of Cash Acquired	$ 0	$ 0	$ 809,390
ATMI [Member]
Acquisitions [Line Items]
Cash paid to ATMI shareholders			1,099,033
Cash paid in settlement of share based compensation awards			31,451
Total purchase price			$ 1,130,484
Less cash and cash equivalents acquired				$ 321,094
Total purchase price, net of cash acquired				$ 809,390