Derivatives (Details Textual) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Maximum period in which contracts for the sale of grain to processors or other consumers extend	1 year
Estimated fair value of inventory	$ 0.3	$ 7.7
Amount reclassified from accumulated and other comprehensive income	0.5	0.3	(0.1)
Amount to be reclassified from accumulated and other comprehensive income in next twelve months	$ (0.5)