Income Taxes (Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Thousands	Jan. 31, 2016	Jan. 31, 2015
Deferred tax assets
Accrued vacation and sick leave	$ 1,106	$ 1,003
Retirement plans	8,837	10,887
Insurance reserves	791	830
Warranty	535	487
Net operating loss carryforwards	10,393	13,303
Intangibles	25	145
Inventory	1,582	1,472
Other	859	595
Total deferred tax assets	24,128	28,722
Deferred tax liabilities
Tax in excess of book depreciation	(1,432)	(1,458)
Other	(87)	(85)
Total deferred tax liabilities	(1,519)	(1,543)
Valuation allowance	(21,906)	(26,399)
Net long term deferred tax asset	$ 703	$ 780