Significant Accounting Policies - Deferred Revenue (Details) - USD ($) $ in Thousands	Jan. 29, 2017	Jan. 31, 2016
Deferred Revenue Arrangement [Line Items]
Deferred revenue	$ 12,059	$ 8,628
Deferred Revenues [Member]
Deferred Revenue Arrangement [Line Items]
Deferred revenue	11,419	5,991
Deferred Cost of Revenues [Member]
Deferred Revenue Arrangement [Line Items]
Deferred revenue	(2,246)	(1,139)
Deferred Revenue, Net [Member]
Deferred Revenue Arrangement [Line Items]
Deferred revenue	9,173	4,852
Deferred Product Design and Engineering Recoveries [Member]
Deferred Revenue Arrangement [Line Items]
Deferred revenue	$ 2,886	$ 3,776