Investment In And Loans To Dynamic Fuels (Narrative) (Details) (USD $)	3 Months Ended			9 Months Ended
	Sep. 30, 2013	Jun. 30, 2013	Sep. 30, 2012	Sep. 30, 2013 gal	Sep. 30, 2012	Dec. 31, 2012 gal
Unusual Risk or Uncertainty [Line Items]
Equity investment in and loans to Dynamic Fuels, LLC	$ 40,365,000			$ 40,365,000		$ 38,407,000
Current accounts receivable from Dynamic Fuels, LLC	6,000			6,000		252,000
Tax credit per gallon of produced renewable diesel				1.00
Tax credit per gallon of produced alternative fuels				0.50
Income tax refund requested				9,700,000
Income tax refunds received		9,000,000
Tax refund, receivable	697,000			697,000
Repayment of working capital loan				9,700,000
Renewable products sold						66,800,000
Plant design production rate per year				75,000,000
Technical services revenue from Dynamic Fuels, LLC	24,000		372,000	469,000	4,803,000
Royalties from Dynamic Fuels, LLC plant production			304,000	0	679,000
Dynamic Fuels, LLC [Member]
Unusual Risk or Uncertainty [Line Items]
Excess value of investment in Dynamic Fuels, LLC	$ 7,700,000			$ 7,700,000