Note 6 - Derivative Instruments and Fair Value Measurements (Detail) (USD $) In Thousands, unless otherwise specified	6 Months Ended			3 Months Ended
	Jun. 30, 2012 bu	Mar. 31, 2012	Dec. 31, 2011	Mar. 31, 2012 Deferred [Member]
Derivative, Number of Instruments Held	10,498,000
Processing Plants Current Output (in US Bushels)	1,750,000
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax		$ (27)
Loss on Cash Flow Hedge Ineffectiveness				(200)
Long-term Debt, Fair Value	7,761		8,647
Long-term Debt	7,693		8,522
Restricted Cash and Investments	2,757		7,605
Collateralized Agreements	$ 962		$ 4,680