Financial Instruments (Details 4) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Derivative [Line Items]
Pre-tax net gains and losses on certain loans designated as hedges of net investments in foreign subsidiaries	$ 37,500,000	$ (2,700,000)	$ (22,600,000)
Proceeds from derivative transaction	16,625,000	75,057,000	$ 0
Foreign currency forward exchange contracts
Derivative [Line Items]
U.S. Dollar Equivalent	600,883,000	592,414,000
Recognized Gain (Loss)	1,394,000	4,090,000
Foreign currency forward exchange contracts | Short [Member] | British pounds sterling
Derivative [Line Items]
U.S. Dollar Equivalent	55,120,000	43,511,000
Recognized Gain (Loss)	(228,000)	822,000
Foreign currency forward exchange contracts | Short [Member] | Euros
Derivative [Line Items]
U.S. Dollar Equivalent	326,797,000	336,397,000
Recognized Gain (Loss)	628,000	547,000
Foreign currency forward exchange contracts | Short [Member] | No currency
Derivative [Line Items]
U.S. Dollar Equivalent	43,455,000	35,426,000
Recognized Gain (Loss)	1,477,000	316,000
Foreign currency forward exchange contracts | Long [Member] | British pounds sterling
Derivative [Line Items]
U.S. Dollar Equivalent	827,000	2,062,000
Recognized Gain (Loss)	(14,000)	(54,000)
Foreign currency forward exchange contracts | Long [Member] | Euros
Derivative [Line Items]
U.S. Dollar Equivalent	171,578,000	167,037,000
Recognized Gain (Loss)	(468,000)	2,497,000
Foreign currency forward exchange contracts | Long [Member] | No currency
Derivative [Line Items]
U.S. Dollar Equivalent	3,106,000	7,981,000
Recognized Gain (Loss)	(1,000)	$ (38,000)
Maturing 2013 through 2017 | Derivatives Designated as Hedging Instruments
Derivative [Line Items]
U.S. Dollar Equivalent	$ 2,700,000.0