Warranty (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Oct. 31, 2014	Oct. 31, 2013	Oct. 31, 2014	Oct. 31, 2013
Warranty claim activity
Beginning balance	$ 1,000	$ 1,000	$ 1,000	$ 1,000
Provision	134	17	352	233
Costs incurred	(134)	(117)	(352)	(333)
Ending balance	$ 1,000	$ 900	$ 1,000	$ 900
Minimum [Member]
Warranty [Line Items]
Product warranty period			5 years
Maximum [Member]
Warranty [Line Items]
Product warranty period			10 years