Other Income, Net (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 31, 2016	Jul. 31, 2015	Jul. 31, 2016	Jul. 31, 2015
Other Income And Expenses [Abstract]
Net gain from disposal of property and equipment	$ 108	$ 210	$ 253	$ 969
Interest income	15	114	63	386
Currency exchange gain (losses)	(62)	111	(146)	(48)
Other	127	(183)	168	(14)
Total	$ 188	$ 252	$ 338	$ 1,293