Derivative Instruments, Hedging Activities and Fair Value (Details 3) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Foreign Currency Derivatives
Pre-tax net gains (losses) on certain loans designated as hedges of net investments in foreign subsidiaries	$ 2,200	$ (15,100)	$ 2,400	$ (20,000)
Foreign currency forward exchange contracts
Foreign Currency Derivatives
U.S. Dollar Equivalent	436,584		436,584		$ 468,822
Recognized Gain (Loss)			6,639	(133)
Foreign currency forward exchange contracts | British pounds sterling | Sell
Foreign Currency Derivatives
U.S. Dollar Equivalent	73		73		37,943
Recognized Gain (Loss)			0	179
Foreign currency forward exchange contracts | British pounds sterling | Buy
Foreign Currency Derivatives
U.S. Dollar Equivalent	46,021		46,021		2,783
Recognized Gain (Loss)			961	(4)
Foreign currency forward exchange contracts | Euros | Sell
Foreign Currency Derivatives
U.S. Dollar Equivalent	126,274		126,274		193,370
Recognized Gain (Loss)			(434)	2,993
Foreign currency forward exchange contracts | Euros | Buy
Foreign Currency Derivatives
U.S. Dollar Equivalent	198,565		198,565		194,084
Recognized Gain (Loss)			5,020	(3,767)
Foreign currency forward exchange contracts | Other currencies | Sell
Foreign Currency Derivatives
U.S. Dollar Equivalent	50,164		50,164		12,641
Recognized Gain (Loss)			1,113	439
Foreign currency forward exchange contracts | Other currencies | Buy
Foreign Currency Derivatives
U.S. Dollar Equivalent	$ 15,487		15,487		$ 28,001
Recognized Gain (Loss)			$ (21)	$ 27