Restructuring and Integration Expenses - Restructuring Reserve Rollforward (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Restructuring Reserve [Roll Forward]
Beginning balance	$ 15,004
Expense	0	$ 45,960	$ 87,307
Payments	(12,933)
Ending balance	2,071	15,004
Severance costs
Restructuring Reserve [Roll Forward]
Beginning balance	3,377	5,528
Expense	0	9,487	18,326
Payments	(3,377)	(11,638)
Ending balance	0	3,377	5,528
Facility exit costs
Restructuring Reserve [Roll Forward]
Beginning balance	6,786	7,621
Expense	0	6,532	13,519
Payments	(4,965)	(7,367)
Ending balance	1,821	6,786	7,621
System consolidation costs
Restructuring Reserve [Roll Forward]
Beginning balance	14	1,064
Expense	0	11,603	20,859
Payments	(14)	(12,653)
Ending balance	0	14	1,064
Legal costs
Restructuring Reserve [Roll Forward]
Beginning balance	4,813	3,519
Expense	0	5,550	3,956
Payments	(4,563)	(4,256)
Ending balance	250	4,813	3,519
Tax and accounting advisory services
Restructuring Reserve [Roll Forward]
Beginning balance	14	0
Expense	0	1,918	14,851
Payments	(14)	(1,904)
Ending balance	0	14	0
Other costs
Restructuring Reserve [Roll Forward]
Beginning balance	18,305	13,216
Expense		10,870	15,796
Payments		(5,781)
Ending balance		18,305	13,216
Total
Restructuring Reserve [Roll Forward]
Beginning balance	$ 33,309	30,948
Expense		45,960
Payments		(43,599)
Ending balance		$ 33,309	$ 30,948