Summary of Significant Accounting Policies narrative (Details)	3 Months Ended
	Jul. 31, 2013 gal
Plant production capacity	60,000,000
Production (Actual)	70,000,000
Measurement, Rolling Twelve Months	twelve
Heron Lake Bioenergy [Member]
Plant production capacity	50,000,000
Production (Actual)	59,000,000