Subsequent events (Details) (USD $)	12 Months Ended
	Jan. 31, 2015
Subsequent Event [Line Items]
Subsequent Event, Date	Apr. 16, 2015
Subsequent Event, Description	First Amendment
Stock Repurchase Program, Authorized Amount	$ 2,000,000
Stock Repurchase Program Expiration Date	Dec. 31, 2015
Property, Plant and Equipment, Dispositions	On March 16, 2015,the Company signed a letter of intent to sell its idle facility in Cicero, Illinois to an unaffiliated third party. The Company does not anticipate that it will recognize a material gain or loss from sale upon closing the transaction.
Cash Surrender Value [Member]
Subsequent Event [Line Items]
Debt Instrument, Face Amount	$ 1,900,000
Debt Instrument, Interest Rate, Stated Percentage	5.00%
United States
Subsequent Event [Line Items]
Description of Material Affects of Noncompliance	Subsequent to January 31, 2015, the Company was not in compliance with the specific level of Borrowing Base availability for the period ended March 31, 2015. While not a covenant violation, the financial institution has the right in the Credit Agreement to have all domestic receipts deposited in a bank account from which all funds may only be used to serve the revolving line of credit under the Credit Agreement.