Derivative Financial Instruments Derivative Financial Instruments Narrative (Details) (USD $)	12 Months Ended							3 Months Ended			12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Dec. 31, 2010	Dec. 31, 2012 Minimum [Member]	Dec. 31, 2012 Maximum [Member]	Dec. 31, 2012 contracts	Sep. 30, 2011 Euro Term Loan Interest Rate Swap [Member]	Jun. 30, 2011	Jun. 30, 2011	Dec. 31, 2012 Forward Contracts [Member]	Dec. 31, 2012 Net Investment Hedging [Member]
Net unrealized loss on hedging instruments	$ (16,069,000)	$ (14,380,000)		$ (10,034,000)								$ 14,400,000
Derivative, Number of Instruments Held							6
Pay fixed interest rate in interst rate swap							1.00%	6.59%	2.11%	2.15%
Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net							629,000
Long-term Debt	417,500,000	452,502,000
Percentage rate above EURIBOR receive on interest rate swap			2.00%					2.00%
Derivative, Description of Variable Rate Basis	Interbank Offered Rate (EURIBOR), plus 2%.
Notional amount of interest rate swaps							200,000,000		100,000,000	100,000,000
Cash Payment to Terminate Interest Rate Swap								2,900,000
Number of USD Term Loan Interest Rate Derivatives Expired	2
Number of foreign exchange forward contracts entered into YTD											560
Notional amount of foreign currency forward contracts					$ 120,000	$ 51,000,000