Condensed Consolidated Statement of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 60,883	$ 30,745	$ 92,580	$ 95,783
Other comprehensive loss, net of tax:
Foreign currency translation adjustment	(3,202)	(8,166)	(12,085)	(8,852)
Change in fair value on available-for-sale investments, net of tax expense of $141 and $314 for the three and nine months ended September 30, 2020, respectively, and zero and $184 for the three and nine months ended September 30, 2019, respectively.	8	0	553	558
Other comprehensive loss, net of tax	(3,194)	(8,166)	(11,532)	(8,294)
Comprehensive income	$ 57,689	$ 22,579	$ 81,048	$ 87,489