Derivative Financial Instruments Derivative Financial Instruments Narrative (Details) (USD $)	9 Months Ended								3 Months Ended	9 Months Ended
	Sep. 30, 2012 contracts	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011 contracts	Dec. 31, 2010	Sep. 30, 2012 Minimum [Member]	Sep. 30, 2012 Maximum [Member]	Sep. 30, 2012 contracts	Sep. 30, 2011 Euro Term Loan Interest Rate Swap [Member]	Sep. 30, 2011 Euro Term Loan Interest Rate Swap [Member]	Jun. 30, 2011	Jun. 30, 2011	Sep. 30, 2012 Net Investment Hedging [Member]
Net unrealized loss on hedging instruments	$ (16,057,000)	$ (14,380,000)	$ (14,368,000)		$ (10,034,000)								$ (14,400,000)
Number of Interest Rate Derivatives Held								6
Long-term Debt	421,250,000	452,502,000
Number of USD Term Loan Interest Rate Derivatives Expired				2
Pay fixed interest rate in interst rate swap								1.00%	6.59%	6.59%	2.11%	2.15%
Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net								256,000
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
Number of foreign exchange forward contracts entered into YTD	429
Notional amount of foreign currency forward contracts						120,000	51,000,000
Cash Payment to Terminate Interest Rate Swap									$ 2,900,000