Derivative Instruments (Details)		3 Months Ended			3 Months Ended
	Mar. 31, 2015 Foreign Exchange Forward [Member] Not Designated as Hedging Instrument [Member] USD ($)	Mar. 31, 2015 Foreign Exchange Contract [Member] USD ($)	Mar. 31, 2014 Foreign Exchange Contract [Member] USD ($)	Dec. 31, 2014 Foreign Exchange Contract [Member] USD ($)	Mar. 31, 2015 Foreign Exchange Contract [Member] Designated as Hedging Instrument [Member] USD ($)	Mar. 31, 2015 United States of America, Dollars [Member] Foreign Exchange Forward [Member] Not Designated as Hedging Instrument [Member] USD ($)	Mar. 31, 2015 United Kingdom, Pounds [Member] Foreign Exchange Forward [Member] Not Designated as Hedging Instrument [Member] GBP (£)	Mar. 31, 2015 Euro Member Countries, Euro [Member] Foreign Exchange Forward [Member] Not Designated as Hedging Instrument [Member] EUR (€)
Derivative Instruments, Gain (Loss) [Line Items]
Foreign currency forward contract	$ 163,000,000					$ 143,000,000	£ 8,900,000	€ 4,700,000
Foreign exchange contracts		1,000,000		100,000
Unrealized gains (losses) recorded to other comprehensive income related to foreign currency hedges					0
Derivative financial instruments revaluation, net of tax		$ 0	$ 200,000