Warranty (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2016	Jan. 31, 2015
Warranty claim activity
Beginning accrued warranty balance	$ 950	$ 1,000
Provision	675	650
Provision for (benefits from) prior year	(250)	(258)
Costs incurred	(375)	(442)
Ending accrued warranty balance	$ 1,000	$ 950
Minimum [Member]
Warranty [Line Items]
Product warranty period	5 years
Maximum [Member]
Warranty [Line Items]
Product warranty period	10 years