Note 4 - Commitments and Contingencies (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013
Long-term Purchase Commitment, Amount	$ 39,826
Letters of Credit Outstanding, Amount	2,000
MMBTU Natual Gas Dollar Equivalent [Member]
Long-term Purchase Commitment, Amount	2,967
Pounds Of Flour Dollar Equivalent [Member]
Long-term Purchase Commitment, Amount	9,935
Capital Expenditures [Member]
Purchase Commitment, Remaining Minimum Amount Committed	$ 607