CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 60,360	$ 63,248	$ 133,153	$ 148,417
Other comprehensive income (loss), net of tax
Foreign currency translation adjustment	863	(767)	(12,086)	(387)
Unrealized gain on investments	0	0	189	0
Reclassification adjustment for realized loss on investments included in net income	0	0	541	0
Total other comprehensive income (loss)	863	(767)	(11,356)	(387)
Total comprehensive income	$ 61,223	$ 62,481	$ 121,797	$ 148,030