Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Statement of Comprehensive Income [Abstract]
Net income	$ 196,888	$ 144,793	$ 377,254	$ 283,224
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	191	1,193	(350)	(1,546)
Net change in unrealized gains (losses) on available-for-sale securities	(466)	5,802	(1,027)	9,226
Other comprehensive income (loss)	(275)	6,995	(1,377)	7,680
Comprehensive income	$ 196,613	$ 151,788	$ 375,877	$ 290,904