Deferred Revenue and Deferred Cost - Schedule of Deferred Revenue and Related Cost (Detail) (USD $) In Thousands, unless otherwise specified	Apr. 30, 2013	Jan. 31, 2013
Deferred Revenue Disclosure [Abstract]
Deferred revenue on product shipments	$ 5,051	$ 3,827
Deferred revenue from licenses	300	485
Deferred cost of revenue on product shipments	(1,327)	(861)
Total deferred income	$ 4,024	$ 3,451