Derivative Financial Instruments Derivative Financial Instruments (Details textual) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Derivative [Line Items]
Net gain (loss)	$ (5,000,000)	$ (1,400,000)	$ (3,500,000)	$ 300,000
Maturities of foreign currency forward contracts			6 months
Level 2 | Interest Rate Swap [Member] | Other Current Assets
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset	$ 2,500,000		$ 2,500,000