CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 139,290	$ 96,784	$ 339,033	$ 249,184
Foreign currency translation	1,471		(3,782)
Unrealized (loss) gain on available-for-sale debt securities, net of tax	(30)		233
Comprehensive income	$ 140,731	$ 96,784	$ 335,484	$ 249,184