Derivative Financial Instruments Derivative and Nonderivative Hedging Instrument Fair Value Disclosure (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Liability Derivatives [Abstract]
Total liability derivatives	$ 2,839	$ 222
Other Current Assets [Member]
Asset Derivatives [Abstract]
Foreign exchange forward contracts	146	241
Other Current Liabilities [Member]
Liability Derivatives [Abstract]
Foreign exchange forward contracts	114	222
Designated as Hedging Instrument [Member] | Other Current Liabilities [Member]
Liability Derivatives [Abstract]
Interest rate swap contracts	629	0
Designated as Hedging Instrument [Member] | Other Long Term Obligations [Member]
Liability Derivatives [Abstract]
Interest rate swap contracts	$ 2,096	$ 0