Derivative Instruments (Details 3) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Derivatives, Fair Value [Line Items]
Total derivatives	$ 453	$ (1,543)
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Total derivatives	453	(1,543)
Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Other Current Assets (Liabilities) [Member]
Derivatives, Fair Value [Line Items]
Total derivatives	(74)	(229)
Not Designated as Hedging Instrument [Member] | Derivative Features of Subordinated Notes [Member] | Long-term Debt & Long Term Debt-Related Party [Member]
Derivatives, Fair Value [Line Items]
Total derivatives	$ 527	$ (1,314)