Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 186,678	$ 122,641	$ 266,799
Other comprehensive loss:
Foreign currency translation adjustments	(5,464)	(37,887)	(7,768)
Change in unrealized gains (losses) on available-for-sale securities, net of tax of $126, $(598), and $(156), respectively	207	(975)	(253)
Total other comprehensive loss	(5,257)	(38,862)	(8,021)
Comprehensive income	$ 181,421	$ 83,779	$ 258,778