Derivative Financial Instruments Derivative Financial Instruments (Details textual) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Derivative [Line Items]
Net gain (loss)	$ 1,400,000	$ 2,600,000	$ (2,100,000)	$ 2,900,000
Maturities of foreign currency forward contracts			7 months
Level 2 | Interest Rate Swap [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Net	1,800,000		1,800,000
Level 2 | Interest Rate Swap [Member] | Other Current Assets
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset	2,800,000		2,800,000
Level 2 | Interest Rate Swap [Member] | Other Current Liabilities
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Liability	$ 1,000,000		$ 1,000,000
Term loan facility [Member]
Derivative [Line Items]
Effective interest rate	2.49%		2.49%