Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 62,894	$ 42,062
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustment (CTA) gain	145,851	106,938
Net investment hedge CTA loss, net of tax effect of $1,637 and $0	(72,635)	(28,551)
Unrealized loss on available-for-sale securities, net of tax effect of $0 and $(99)	0	(265)
Unrealized loss on cash flow hedges, net of tax effects of $1,360 and $4,051	(4,080)	(11,727)
Net actuarial gain on defined benefit plans, net of tax effects of $(6) and $(6)	8	11
Total other comprehensive income, net of tax	69,144	66,406
Comprehensive income, net of tax	$ 132,038	$ 108,468