Deferred Acquisition Consideration (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance of contingent payments		$ 74,671		$ 74,671	$ 82,598
Payments		30,719		41,326
Redemption value adjustments	$ 3,573	15,451	$ 3,483	2,814	(2,617)
Additions		7,145		7,703
Foreign translation adjustment		$ 196		2,020
Ending balance of contingent payments	45,882			45,882
Deferred acquisition consideration	46,145			46,145		$ 75,220
Loss (Income) attributable to fair value adjustments	(2,803)		(1,943)	(515)	3,627
Stock-based compensation	770		1,540	2,299	1,010
Fixed payments
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Deferred acquisition consideration	263			263		$ 549
Contingent Payment
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Loss (Income) attributable to fair value adjustments	$ 2,803		$ 1,943	$ 515	$ (3,627)