Goodwill and Intangible Assets - Carrying Amounts of Amortizable Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Finite-lived Intangible Assets [Roll Forward]
Gross cost, beginning balance	$ 1,301,120
Foreign currency translation impact	(37,925)
Gross cost, ending balance	1,263,195
Accumulated amortization	(399,045)		$ (376,033)
Finite-lived intangible assets, net	864,150		925,087
Amortization of intangibles	32,179	$ 33,683
Customer Relationships
Finite-lived Intangible Assets [Roll Forward]
Gross cost, beginning balance	1,145,109
Foreign currency translation impact	(36,507)
Gross cost, ending balance	1,108,602
Accumulated amortization	(299,121)		(283,369)
Finite-lived intangible assets, net	$ 809,481		861,740
Customer Relationships | Minimum
Finite-lived Intangible Assets [Roll Forward]
Finite-lived intangible assets useful life	4 years
Customer Relationships | Maximum
Finite-lived Intangible Assets [Roll Forward]
Finite-lived intangible assets useful life	13 years
Software
Finite-lived Intangible Assets [Roll Forward]
Gross cost, beginning balance	$ 111,033
Foreign currency translation impact	(1,171)
Gross cost, ending balance	109,862
Accumulated amortization	(66,478)		(61,564)
Finite-lived intangible assets, net	$ 43,384		49,469
Software | Minimum
Finite-lived Intangible Assets [Roll Forward]
Finite-lived intangible assets useful life	3 years
Software | Maximum
Finite-lived Intangible Assets [Roll Forward]
Finite-lived intangible assets useful life	7 years
Content
Finite-lived Intangible Assets [Roll Forward]
Gross cost, beginning balance	$ 14,140
Foreign currency translation impact	(175)
Gross cost, ending balance	13,965
Accumulated amortization	(12,302)		(11,225)
Finite-lived intangible assets, net	$ 1,663		2,915
Content | Minimum
Finite-lived Intangible Assets [Roll Forward]
Finite-lived intangible assets useful life	1 year 6 months
Content | Maximum
Finite-lived Intangible Assets [Roll Forward]
Finite-lived intangible assets useful life	4 years
Other
Finite-lived Intangible Assets [Roll Forward]
Gross cost, beginning balance	$ 30,838
Foreign currency translation impact	(72)
Gross cost, ending balance	30,766
Accumulated amortization	(21,144)		(19,875)
Finite-lived intangible assets, net	$ 9,622		$ 10,963
Other | Minimum
Finite-lived Intangible Assets [Roll Forward]
Finite-lived intangible assets useful life	2 years
Other | Maximum
Finite-lived Intangible Assets [Roll Forward]
Finite-lived intangible assets useful life	11 years