Derivative Financial Instruments Derivative and Nonderivative Hedging Instrument Fair Value Disclosure (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Liability Derivatives [Abstract]
Derivative Liability, Fair Value, Gross Liability	$ 3,174	$ 2,839
Other Current Assets [Member]
Asset Derivatives [Abstract]
Foreign exchange forward contracts asset	185	146
Designated as Hedging Instrument [Member] | Other Current Liabilities [Member]
Liability Derivatives [Abstract]
Interest Rate Derivative Liabilities, at Fair Value	963	629
Designated as Hedging Instrument [Member] | Other Long Term Obligations [Member]
Liability Derivatives [Abstract]
Interest Rate Derivative Liabilities, at Fair Value	1,854	2,096
Not Designated as Hedging Instrument [Member] | Other Long Term Obligations [Member]
Liability Derivatives [Abstract]
Foreign exchange forward contracts liability	$ 357	$ 114