Property and Equipment, Net - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended		12 Months Ended
	Oct. 31, 2013	Oct. 31, 2012	Oct. 31, 2013	Oct. 31, 2012	Jan. 31, 2013
Property Plant And Equipment [Abstract]
Depreciation expense	$ 434	$ 391	$ 1,298	$ 1,029
Cost of equipment held pursuant to capital leases	14,497		14,497		14,450
Accumulated amortization			$ 10,624		$ 9,752