Restructuring (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Restructuring Cost and Reserve [Line Items]
Restructuring charge	$ 37,286	$ 17,153	$ 27,594
Restructuring Reserve [Roll Forward]
Balance	5,957	10,981	14,243
Costs incurred	28,545	17,153	27,594
Cash disbursements	(11,748)	(18,431)	(24,854)
Software and other non-cash charges	(833)	(3,784)	(6,529)
Translation adjustments and other	130	38	527
Balance	22,051	5,957	10,981
Employee Severance and Related Benefits
Restructuring Reserve [Roll Forward]
Balance	5,707	10,508	12,857
Costs incurred	26,332	12,455	15,841
Cash disbursements	(10,118)	(17,294)	(18,922)
Software and other non-cash charges	0	0	0
Translation adjustments and other	130	38	732
Balance	22,051	5,707	10,508
Software Charges
Restructuring Reserve [Roll Forward]
Balance	99	198	0
Costs incurred	833	3,784	4,940
Cash disbursements	(99)	(99)	0
Software and other non-cash charges	(833)	(3,784)	(4,742)
Translation adjustments and other	0	0	0
Balance	0	99	198
Other
Restructuring Reserve [Roll Forward]
Balance	151	275	1,386
Costs incurred	1,380	914	6,813
Cash disbursements	(1,531)	(1,038)	(5,932)
Software and other non-cash charges	0	0	(1,787)
Translation adjustments and other	0	0	(205)
Balance	0	151	275
2020 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Restructuring charge	23,600
2020 Restructuring Plan | Employee Severance and Related Benefits
Restructuring Cost and Reserve [Line Items]
Expected restructuring charge	7,000
2019 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Restructuring cost incurred to date	23,400
Restructuring charge	13,200	$ 10,200
Impairment loss on right-of-use asset	8,700
2018 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Restructuring cost incurred to date	19,000
Restructuring charge	$ 6,700		$ 12,300