Schedule II - Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
Jan. 31, 2018	Jan. 31, 2017	Jan. 31, 2016
Allowance for doubtful accounts
Valuation and Qualifying Accounts Disclosure [Line Items]
Valuation Allowances and Reserves, Beginning Balance	$ 200	$ 200	$ 200
Valuation Allowances and Reserves, Charged to (Reduced from) Expenses	55	110	141
Valuation Allowances and Reserves, Deductions from Reserves	55	110	141
Valuation Allowances and Reserves, Ending Balance	200	200	200
Warranty reserve
Valuation and Qualifying Accounts Disclosure [Line Items]
Valuation Allowances and Reserves, Beginning Balance	1,000	1,000	950
Valuation Allowances and Reserves, Charged to (Reduced from) Expenses	380	415	375
Valuation Allowances and Reserves, Deductions from Reserves	455	415	325
Valuation Allowances and Reserves, Ending Balance	925	1,000	1,000
Product, general, workers’ compensation and automobile liability reserves
Valuation and Qualifying Accounts Disclosure [Line Items]
Valuation Allowances and Reserves, Beginning Balance	1,650	2,050	2,130
Valuation Allowances and Reserves, Charged to (Reduced from) Expenses	1,101	777	975
Valuation Allowances and Reserves, Deductions from Reserves	1,404	1,177	1,055
Valuation Allowances and Reserves, Ending Balance	1,347	1,650	2,050
Deferred tax valuation allowance
Valuation and Qualifying Accounts Disclosure [Line Items]
Valuation Allowances and Reserves, Beginning Balance	515	21,906	26,399
Valuation Allowances and Reserves, Charged to (Reduced from) Expenses	410	0	0
Valuation Allowances and Reserves, Deductions from Reserves	0	21,391	4,493
Valuation Allowances and Reserves, Ending Balance	$ 925	$ 515	$ 21,906

Total of allowances and reserves, the valuation and qualifying accounts that are either netted against the cost of an asset (in order to value it at its carrying value) or that reflect a liability established to represent expected future costs.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 4
-Subparagraph (SX 210.12-09)
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24092-122690

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