Revenue (Details) (USD $)	3 Months Ended		9 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Revenue from External Customer [Line Items]
Revenues	$ 40,894,385	$ 33,111,549	$ 135,781,429	$ 118,452,914
Ethanol [Member]
Revenue from External Customer [Line Items]
Revenues	30,669,000	24,437,000	98,809,000	89,578,000
Distillers' Grains [Member]
Revenue from External Customer [Line Items]
Revenues	9,373,000	7,785,000	34,171,000	25,636,000
Other [Member]
Revenue from External Customer [Line Items]
Revenues	$ 852,000	$ 859,000	$ 2,801,000	$ 3,245,000