Note 7 - Loan and Credit Agreements (Details Textual)	6 Months Ended	12 Months Ended
	May. 31, 2015 USD ($)	Nov. 30, 2014 USD ($)	May. 29, 2014 USD ($)	May. 01, 2013 USD ($)	Feb. 01, 2013	May. 10, 2012 USD ($)	May. 01, 2010 USD ($)
US Bank New Loans [Member]
Debt Instrument, Face Amount				$ 6,319,000
Debt Instrument, Interest Rate, Stated Percentage				2.98%
Debt Instrument, Periodic Payment	$ 93,850
Debt Instrument, Periodic Payment Terms, Balloon Payment to be Paid	$ 1,372,000
Debt Instrument Covenant Debt to Tangible Net Worth Ratio	1.5
Debt Instrument Covenant Fixed Charge Coverage Ratio	1.15
Debt Instrument Covenant Interest Rate Increase in Event of Default	5.00%
US Bank [Member]
Debt Instrument, Face Amount			$ 1,000,000			$ 880,000
Term Loan Final Payment			$ 890,000			$ 283,500
Debt Instrument Covenant Interest Rate Increase in Event of Default	5.00%
Iowa Finance Authority [Member]
Debt Instrument, Face Amount							$ 1,300,000
Debt Instrument, Interest Rate, Stated Percentage	2.75%	2.75%			2.75%		3.50%
Debt Instrument, Periodic Payment	$ 12,500	$ 12,500
Debt Instrument Covenant Debt Service Coverage Ratio					1.5
Line of Credit Facility, Maximum Borrowing Capacity	$ 8,000,000
Debt Instrument, Interest Rate, Stated Percentage Rate Range, Minimum	3.50%
Line of Credit Facility, Interest Rate at Period End	3.50%
Long-term Line of Credit	$ 3,318,878
Line of Credit Facility, Remaining Borrowing Capacity	$ 4,255,255
Line of Credit Facility Borrowing Capacity Borrowing Base Percentage of Accounts Receivable	75.00%
Line of Credit Facility Borrowing Capacity Borrowing Base Minimum Percentage of Aggregate Receivables	20.00%
Line of Credit Facility Borrowing Capacity Borrowing Base Percentage of Inventory	50.00%
Line of Credit Facility Borrowing Capacity Borrowing Base Maximum Inventory Amount	$ 6,000,000