Derivative Instruments, Hedging Activities and Fair Value (Details 3) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 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	$ 1,500	$ (4,600)	$ 4,600	$ (4,900)
Foreign currency forward exchange contracts
Foreign Currency Derivatives
U.S. Dollar Equivalent	496,430		496,430		$ 468,822
Recognized Gain (Loss)			(2,049)	(133)
Foreign currency forward exchange contracts | British pounds sterling | Sell
Foreign Currency Derivatives
U.S. Dollar Equivalent	39,281		39,281		37,943
Recognized Gain (Loss)			348	179
Foreign currency forward exchange contracts | British pounds sterling | Buy
Foreign Currency Derivatives
U.S. Dollar Equivalent	2,870		2,870		2,783
Recognized Gain (Loss)			31	(4)
Foreign currency forward exchange contracts | Euros | Sell
Foreign Currency Derivatives
U.S. Dollar Equivalent	227,860		227,860		193,370
Recognized Gain (Loss)			(2,394)	2,993
Foreign currency forward exchange contracts | Euros | Buy
Foreign Currency Derivatives
U.S. Dollar Equivalent	183,539		183,539		194,084
Recognized Gain (Loss)			(621)	(3,767)
Foreign currency forward exchange contracts | Other currencies | Sell
Foreign Currency Derivatives
U.S. Dollar Equivalent	12,571		12,571		12,641
Recognized Gain (Loss)			399	439
Foreign currency forward exchange contracts | Other currencies | Buy
Foreign Currency Derivatives
U.S. Dollar Equivalent	$ 30,309		30,309		$ 28,001
Recognized Gain (Loss)			$ 188	$ 27