Warranty (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2019	Jan. 31, 2018
Warranty claim activity
Beginning accrued warranty balance	$ 925	$ 1,000
Provision	600	760
Provision for (benefits from) prior year	(555)	(380)
Costs incurred	(270)	(455)
Ending accrued warranty balance	$ 700	$ 925
Minimum [Member]
Warranty [Line Items]
Product warranty period	10 years
Maximum [Member]
Warranty [Line Items]
Product warranty period	10 years