Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 26,335	$ 71,018	$ 50,031	$ 124,133
Other comprehensive income (loss):
Foreign currency translation adjustments	5,560	1,918	(33,930)	2,379
Change in unrealized gains on available-for-sale securities, net of tax of $25, $51, $158 and $342, respectively	(526)	81	256	548
Total other comprehensive (loss) income	5,034	1,999	(33,674)	2,927
Comprehensive income	$ 31,369	$ 73,017	$ 16,357	$ 127,060