Condensed Consolidated Statements of Comprehensive Income (Loss) (unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 26,831	$ (15,946)	$ 104,532	$ (121,447)
Unrealized gains (losses) on marketable securities, net of taxes	(176)	0	131	0
Foreign currency translation adjustments	982	(1,017)	966	(984)
Other comprehensive income	806	(1,017)	1,097	(984)
Comprehensive income (loss)	27,637	(16,963)	105,629	(122,431)
Taxes on unrealized gains (losses) on marketable securities	$ (99)	$ 0	$ 9	$ 0