Note 7 - Loan and Credit Agreements (Detail) (USD $)	1 Months Ended	3 Months Ended	62 Months Ended											1 Months Ended					9 Months Ended	12 Months Ended	3 Months Ended
	May 31, 2010	Aug. 31, 2012	Jul. 31, 2014	Apr. 30, 2013	May 31, 2012	May 10, 2012	Apr. 26, 2012	Nov. 30, 2011	Sep. 15, 2010	Jun. 30, 2009	Nov. 30, 2007	Oct. 09, 2007	Jun. 07, 2007	Apr. 30, 2017 West Bank [Member] Term Loan [Member]	Apr. 30, 2017 West Bank [Member] Monona Construction [Member]	Apr. 30, 2017 West Bank [Member] Dubuque Construction [Member]	May 31, 2017 West Bank [Member]	May 31, 2017 US Bank [Member]	Aug. 31, 2012 US Bank [Member]	Nov. 30, 2011 US Bank [Member]	Aug. 31, 2012 Universal Harvester Co [Member]	Jun. 30, 2009 Promissory Note 1 [Member]	Jun. 30, 2009 Promissory Note 2 [Member]
Line of Credit Facility, Maximum Borrowing Capacity				$ 6,000,000
Debt Instrument, Interest Rate, Stated Percentage Rate Range, Minimum		4.00%
Line of Credit Facility, Amount Outstanding		642,000						1,389,000
Line of Credit Facility, Remaining Borrowing Capacity		5,358,000						4,611,000
Line of Credit Facility, Covenant Terms		60%
Long-term Debt	1,300,000	8,739,368			2,000,000	880,000	2,659,000	6,456,121	13,000				4,100,000						851,897	0.00		95,000	95,000
Debt Instrument, Periodic Payment		1,583												536,000	628,000	711,000	666,000	283,500	11,700	11,700
Construction Loan							$ 1,074,000				$ 1,500,000	$ 1,330,000
Debt Instrument, Payment Terms		Each of the Company's loans from West Bank is governed by the Business Loan Agreement, which requires the Company to comply with certain financial and reporting covenants. The Company must provide monthly internally prepared financial reports, year-end audited financial statements, annual compliance certificates, and notice upon certain events, such as a change in executive or management personnel.The Company must maintain a minimum debt service coverage ratio of 1.5, a maximum debt to tangible net worth ratio of 1.25, and a minimum tangible net worth of $12,000,000, each as measured at the Company's fiscal year-end. Further, the Company must obtain West Bank's prior written consent for any investment in, acquisition of, or guaranty relating to another business or entity. The loans are secured by a first position security interest on the assets of the Company and its subsidiaries, including but not limited to, inventories, accounts receivable, machinery, equipment and real estate, in accordance with the Business Loan Agreement, Real Estate Mortgages, Commercial Security Agreements, and Commercial Guaranties previously executed by the Company's subsidiaries. The Company and its subsidiaries were also required to execute Agreements to Provide Insurance that set forth the insurance requirements for the collateral. If the Company or either of its subsidiaries (as guarantors) commits an event of default under the Business Loan Agreement and fails or is unable to cure that default, the interest rate on the Line of Credit would increase by 2.0%. In addition, West Bank may cease advances under the Line of Credit and has the option of causing all outstanding indebtedness to become immediately due and payable. Events of default include, without limitation: (i) becoming insolvent or subject to bankruptcy proceedings; (ii) defaulting on any obligations to West Bank; (iii) defaulting on any obligations to third parties that would materially affect the ability to perform obligations owed to West Bank; (iv) suffering a material adverse change in financial condition or the value of any collateral; (v) experiencing a change in ownership of twenty-five percent or more of outstanding common stock; and (vi) making false statements to West Bank
Debt Instrument, Interest Rate, Stated Percentage									0.00%	0.00%									3.15%	3.15%
Debt Instrument, Frequency of Periodic Payment			60
Debt Instrument, Covenant Description	1.5 to 1.0	If the Company fails to make a required payment or perform any other covenant under the IFA Loan Agreement or the West Union Mortgage, becomes subject to bankruptcy or insolvency proceedings, defaults in payment on any of our other loan obligations in excess of $100,000, or if there is a determination that any of the Company's representations made in the IFA Loan Agreement or related documents are materially false, the Company will be deemed to have committed an event of default under the IFA Loan Agreement.If the Company does not cure the event of default within the time specified by the IFA Loan Agreement, the lender may cause the entire amount of the loan to be immediately due and payable and take any other action that it is lawfully permitted to take or in equity to enforce the Company's performance																			If the Company fails to make a required payment or perform or observe any agreement or covenant under the U.S. Bank Loan, commits and fails to cure a default under the terms of any of our other loan obligations in excess of $10,000, becomes subject to bankruptcy, insolvency proceedings, or a judgment in an amount exceeding $10,000, if there is a determination that any of the representations made in the U.S. Bank Loan or ancillary documents are untrue or materially misleading or if there is a material adverse change in our business, we will be deemed to be in default under the U.S. Bank Loan.If we do not cure the default within the applicable cure period, the lender may cause the entire amount of the loan to be immediately due and payable or may increase the interest rate to a rate of 5.00% per annum, plus the interest rate otherwise payable under the U.S. Bank Loan
Debt Instrument, Covenant Compliance		The Company was in compliance with all covenants under the IFA Loan Agreement as measured on November 30, 2011 and the Company remains in compliance with the terms of the IFA Loan Agreement