Derivative Instruments (Fair Value of Derivative Instruments Designated as Hedging Instruments Recorded in the Condensed Consolidated Balance Sheets) (Details) (USD $) In Thousands	Jun. 30, 2011	Dec. 31, 2010
Designated as Hedging Instrument [Member]
Derivative Asset, Fair value
Derivative Liabilities, Fair value	(271)	(393)
Designated as Hedging Instrument [Member] | Other Current Assets [Member] | Commodity Contracts [Member]
Derivative Asset, Fair value
Designated as Hedging Instrument [Member] | Other Current Liabilities [Member] | Interest Rate Swap Agreements [Member]
Derivative Liabilities, Fair value	(271)	(393)
Not Designated as Hedging Instrument [Member]
Derivative Liabilities, Fair value		(378)
Not Designated as Hedging Instrument [Member] | Other Current Liabilities [Member] | Commodity Contracts [Member]
Derivative Liabilities, Fair value		$ (378)