Property and Equipment, Net - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Oct. 31, 2016	Oct. 31, 2015	Oct. 31, 2016	Oct. 31, 2015
Property Plant And Equipment [Abstract]
Depreciation	$ 1.2	$ 1.1	$ 3.6	$ 1.9