Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 546,593	$ 447,286	$ 501,426
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments	(1,432)	5,620	7,618
Unrealized holding (loss) gain on investments:
Unrealized holding (losses) gains during the period, net of income taxes of $728, $(134) and $(461)	(2,527)	374	1,486
Less: reclassification adjustment for losses realized in net income, net of income taxes of $(246), $(190) and $(101)	914	712	392
Total other comprehensive (loss) income, net of taxes	(3,045)	6,706	9,496
Comprehensive income	$ 543,548	$ 453,992	$ 510,922