Warranties (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2018	Jan. 31, 2017	Jan. 31, 2016
Movement in Standard Product Warranty Accrual [Roll Forward]
Beginning balance	$ 1,547	$ 1,835	$ 3,120
Change in provision	1,762	1,597	1,945
Settlements made	(2,146)	(1,885)	(3,230)
Ending balance	$ 1,163	$ 1,547	$ 1,835