Income Taxes (Deferred Tax Assets and Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	Jan. 31, 2013	Jan. 31, 2012
Deferred tax assets
Accrued vacation and sick leave	$ 830	$ 879
Retirement plans	10,343	9,820
Insurance reserves	1,193	1,183
Warranty	451	595
Net operating loss carryforwards	12,072	11,255
Intangibles	272	338
Inventory	723	146
Other	1,250	1,486
Total deferred tax assets	27,134	25,702
Deferred tax liabilities
Tax in excess of book depreciation	(1,540)	(1,793)
Other	(81)	(71)
Total deferred tax liabilities	(1,621)	(1,864)
Valuation allowance	(24,601)	(22,859)
Net deferred tax asset	912	979
Current deferred tax liabilities	(572)	(1,221)
Long-term deferred tax assets	$ 1,484	$ 2,200