Derivative Instruments (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010 contract	Dec. 31, 2009
Euro Forward Contracts [Member]
Derivatives, Fair Value [Line Items]
Notional amount of derivatives	$ 90,000,000
Cash flow hedges expected to be reclassified to earnings	(3,700,000)
Number of derivatives held		0
Derivative instruments maturity range, months	12 months
Hedge ineffectiveness recorded to income	0	0	0
Interest Rate Swap Agreements [Member]
Derivatives, Fair Value [Line Items]
Notional amount of derivatives	199,500,000	60,000,000
Cash flow hedges expected to be reclassified to earnings	(400,000)
Number of derivatives held			0
Derivative instruments maturity range, months	12 months
Hedge ineffectiveness recorded to income	$ 0	$ 0	$ 0