Warranties (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2017	Jan. 31, 2016	Jan. 31, 2015
Movement in Standard Product Warranty Accrual [Roll Forward]
Beginning balance	$ 1,835	$ 3,120	$ 2,525
Acquired	0	0	50
Accrual for warranties	1,597	1,945	3,467
Settlements made	(1,885)	(3,230)	(2,922)
Ending balance	$ 1,547	$ 1,835	$ 3,120