Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 557,054	$ 478,035	$ 298,373
Other comprehensive income (loss):
Foreign currency translation adjustments	19,629	(1,020)	(27,585)
Change in unrealized gain on investments, net of income tax provision of $2,720, $666 and $200 for the years ended December 31, 2020, 2019 and 2018, respectively	5,314	4,788	603
Other comprehensive income (loss)	24,943	3,768	(26,982)
Comprehensive income	$ 581,997	$ 481,803	$ 271,391