UNAUDITED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) - 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]
Tax (benefit) associated with gain (loss) on net investment hedges	$ (59,607)	$ (12,867)	$ (179,948)	$ (47,023)
Tax (benefit) associated with gain (loss) on marketable securities	8,618	1,900	24,549	36,824
Amount of gain (loss) on marketable securities which are non-taxable	$ (57,728)	$ 167,673	$ 427,349	$ (74,885)