Deferred Revenue and Deferred Cost - Schedule of Deferred Revenue and Related Cost (Detail) - USD ($) $ in Thousands	Jan. 31, 2017	Jan. 31, 2016
Deferred Revenue Disclosure [Abstract]
Deferred revenue on product shipments	$ 7,725	$ 12,201
Deferred revenue from licenses & services	1,748	1,653
Deferred cost of revenue on product shipments	(2,048)	(3,777)
Total deferred revenue, net	$ 7,425	$ 10,077