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	$ 279,881	$ 176,186	$ 203,865
Available-for-sale investments:
Net unrealized gain (loss), net of tax of $(2,206), $981, and $515 in 2021, 2020, and 2019, respectively	(7,152)	6,478	5,219
Reclassification of net realized (gain) loss into current operations	(236)	(4,119)	(1,452)
Net change related to available-for-sale investments	(7,388)	2,359	3,767
Foreign currency translation adjustments:
Foreign currency translation adjustments	(6,753)	1,115	(541)
Net change related to foreign currency translation adjustments	(6,753)	1,115	(541)
Other comprehensive income (loss), net of tax	(14,141)	3,474	3,226
Total comprehensive income	$ 265,740	$ 179,660	$ 207,091