Warranty (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Jan. 31, 2015	Jan. 31, 2014
Warranty claim activity
Beginning accrued warranty balance	$ 1,000	$ 1,000
Provision	650	600
Provision for (benefits from) prior year	(258)	(220)
Costs incurred	(442)	(380)
Ending accrued warranty balance	$ 950	$ 1,000
Minimum [Member]
Warranty [Line Items]
Product warranty period	5 years
Maximum [Member]
Warranty [Line Items]
Product warranty period	10 years