Schedule II - Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Allowance for doubtful accounts
Valuation and Qualifying Accounts Disclosure [Line Items]
Valuation Allowances and Reserves, Beginning Balance	$ 200	$ 200	$ 275
Valuation Allowances and Reserves, Charged to (Reduced from) Expenses	141	115	3
Valuation Allowances and Reserves, Deductions from Reserves	141	115	78
Valuation Allowances and Reserves, Ending Balance	200	200	200
Warranty reserve
Valuation and Qualifying Accounts Disclosure [Line Items]
Valuation Allowances and Reserves, Beginning Balance	950	1,000	1,000
Valuation Allowances and Reserves, Charged to (Reduced from) Expenses	375	442	380
Valuation Allowances and Reserves, Deductions from Reserves	325	492	380
Valuation Allowances and Reserves, Ending Balance	1,000	950	1,000
Product, general, workers’ compensation and automobile liability reserves
Valuation and Qualifying Accounts Disclosure [Line Items]
Valuation Allowances and Reserves, Beginning Balance	2,130	2,425	2,985
Valuation Allowances and Reserves, Charged to (Reduced from) Expenses	975	204	1,546
Valuation Allowances and Reserves, Deductions from Reserves	1,290	499	2,106
Valuation Allowances and Reserves, Ending Balance	1,815	2,130	2,425
Deferred tax valuation allowance
Valuation and Qualifying Accounts Disclosure [Line Items]
Valuation Allowances and Reserves, Beginning Balance	26,399	24,210	24,601
Valuation Allowances and Reserves, Charged to (Reduced from) Expenses	0	2,189	0
Valuation Allowances and Reserves, Deductions from Reserves	4,493	0	391
Valuation Allowances and Reserves, Ending Balance	$ 21,906	$ 26,399	$ 24,210