Unaudited Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 202,823	$ 129,618	$ 457,503	$ 356,961
Other comprehensive (loss) income:
Foreign currency translation gains (losses), net of tax	112,301	(52,409)	168,655	(41,339)
Reclassification of foreign currency translation loss to investment, net of tax	31,381	0	31,381	0
Total other comprehensive income (loss)	143,682	(52,409)	200,036	(41,339)
Total comprehensive income	$ 346,505	$ 77,209	$ 657,539	$ 315,622