Restructuring (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Restructuring Reserve [Roll Forward]
Balance	$ 10,981	$ 14,243	$ 1,613
Costs incurred	17,153	27,594	54,884
Cash disbursements	(18,431)	(24,854)	(9,110)
Software and other non-cash charges	(3,784)	(6,529)	(33,144)
Translation adjustments and other	38	527
Balance	5,957	10,981	14,243
Employee Severance and Related Benefits
Restructuring Reserve [Roll Forward]
Balance	10,508	12,857	1,444
Costs incurred	12,455	15,841	17,311
Cash disbursements	(17,294)	(18,922)	(5,898)
Software and other non-cash charges	0	0	0
Translation adjustments and other	38	732
Balance	5,707	10,508	12,857
Software Charges
Restructuring Reserve [Roll Forward]
Balance	198	0	0
Costs incurred	3,784	4,940	31,965
Cash disbursements	(99)	0	0
Software and other non-cash charges	(3,784)	(4,742)	(31,965)
Translation adjustments and other	0	0
Balance	99	198	0
Excess Facilities, Contract Terminations and Other
Restructuring Reserve [Roll Forward]
Balance	275	1,386	169
Costs incurred	914	6,813	5,608
Cash disbursements	(1,038)	(5,932)	(3,212)
Software and other non-cash charges	0	(1,787)	(1,179)
Translation adjustments and other	0	(205)
Balance	151	275	1,386
2019 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Restructuring charges recognized	10,200
2018 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Restructuring charges recognized	6,700	12,300
Restructuring and Related Cost, Cost Incurred to Date	19,000
2017 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Restructuring charges recognized		$ 13,400	$ 49,300
Restructuring and Related Cost, Cost Incurred to Date	62,700
Minimum | 2019 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Expected restructuring charge	4,000
Maximum | 2019 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Expected restructuring charge	$ 7,000