Derivative Financial Instruments Derivative Financial Instruments Narrative (Details) (USD $)			9 Months Ended												9 Months Ended
	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013 Forward Contracts [Member]	Sep. 30, 2013 Secured Debt [Member]	Dec. 31, 2012 Secured Debt [Member]	Sep. 30, 2013 Interest Rate Swap [Member] contracts	Sep. 30, 2013 Foreign Exchange Contract [Member] Not Designated as Hedging Instrument [Member] Minimum [Member]	Sep. 30, 2013 Foreign Exchange Contract [Member] Not Designated as Hedging Instrument [Member] Maximum [Member]	Sep. 30, 2013 Accumulated Other Comprehensive Income, Net Unrealized Gain (Loss) on Nonderivative Instruments [Member]	Dec. 31, 2012 Accumulated Other Comprehensive Income, Net Unrealized Gain (Loss) on Nonderivative Instruments [Member]	Sep. 30, 2012 Accumulated Other Comprehensive Income, Net Unrealized Gain (Loss) on Nonderivative Instruments [Member]	Dec. 31, 2011 Accumulated Other Comprehensive Income, Net Unrealized Gain (Loss) on Nonderivative Instruments [Member]	Sep. 30, 2013 Accumulated Other Comprehensive Income, Net Unrealized Gain (Loss) on Nonderivative Instruments [Member] Net Investment Hedging [Member]	Dec. 31, 2012 Accumulated Other Comprehensive Income, Net Unrealized Gain (Loss) on Nonderivative Instruments [Member] Net Investment Hedging [Member]	Sep. 30, 2013 Number of Counterparties [Member]
Description of Derivative Activity Volume			a total of 385 contracts were entered into												Our derivative assets and liabilities consist of foreign exchange forward and interest rate swap contracts with eight counterparties at September 30, 2013 and December 31, 2012.
Net unrealized loss on hedging instruments	$ 36,333,000	$ 34,384,000							$ 14,380,000	$ 14,380,000	$ 14,380,000	$ 14,380,000	$ 14,400,000	$ 14,400,000
Number of Interest Rate Derivatives Held						6
Derivative, Notional Amount						200,000,000	251,000	11,000,000
Pay fixed interest rate in interst rate swap						1.00%
Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net						(1,600,000)
Long-term Debt				$ 399,375,000	$ 417,500,000