Restructuring, Acquisition and Integration (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2018	Dec. 31, 2017
Restructuring Reserve [Roll Forward]
Beginning balance		$ 7,681	$ 30,129
Restructuring charges	$ 96,300	41,030	20,930
Cash payments / adjustments		(39,205)	(40,638)
Non-cash expense		(911)	(2,740)
Ending balance		8,595	7,681
Employee severance & termination benefits
Restructuring Reserve [Roll Forward]
Beginning balance		4,379	27,886
Restructuring charges		38,512	13,346
Cash payments / adjustments		(38,056)	(35,955)
Non-cash expense		0	(898)
Ending balance		4,835	4,379
Contractual obligations and other
Restructuring Reserve [Roll Forward]
Beginning balance		3,302	2,243
Restructuring charges		1,607	5,742
Cash payments / adjustments		(1,149)	(4,683)
Non-cash expense		0	0
Ending balance		3,760	3,302
Write-off of property, plant and equipment
Restructuring Reserve [Roll Forward]
Beginning balance		0	0
Restructuring charges		911	1,842
Cash payments / adjustments		0	0
Non-cash expense		(911)	(1,842)
Ending balance		$ 0	$ 0