Deferred Rent - Deferred Rent (Detail) - USD ($) $ in Thousands	Apr. 30, 2017	Jan. 31, 2017
Deferred Revenue Disclosure [Abstract]
Leasehold improvement incentive	$ 1,518	$ 1,582
Non-cash rent expense	1,275	1,349
Total deferred rent	2,793	2,931
Less current portion included in accrued expenses	(533)	(540)
Deferred rent, net of current portion	$ 2,260	$ 2,391