Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss)
Beginning balance	$ 2,780	$ 85,580	$ 42,069
Net other comprehensive (loss) income	(32,616)	(95,454)	68,570
Ending balance	(29,199)	2,780	85,580
Foreign currency translation adjustment
Accumulated Other Comprehensive Income (Loss)
Beginning balance	(23,621)	(23,202)	(23,336)
Net other comprehensive (loss) income	(117)	(419)	134
Ending balance	(23,738)	(23,621)	(23,202)
Unrealized gain (loss) on marketable securities, net
Accumulated Other Comprehensive Income (Loss)
Beginning balance	205	(64)	(229)
Net other comprehensive (loss) income	727	269	165
Ending balance	932	205	(64)
Accumulated other comprehensive loss
Accumulated Other Comprehensive Income (Loss)
Beginning balance	(23,416)	(23,266)	(23,565)
Ending balance	$ (22,806)	$ (23,416)	$ (23,266)