Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 29,432	$ 59,295	$ 79,463	$ 183,428
Other comprehensive income (loss):
Foreign currency translation adjustments	302	(4,354)	(33,628)	(1,975)
Change in unrealized gains on available-for-sale securities, net of tax of $(45), $(313), $113 and $28, respectively	(72)	(503)	184	45
Total other comprehensive income (loss)	230	(4,857)	(33,444)	(1,930)
Comprehensive income	$ 29,662	$ 54,438	$ 46,019	$ 181,498