Income Taxes - Reconciliation of Income Taxes by Jurisdiction (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Jan. 31, 2018	Oct. 31, 2017	Jul. 31, 2017	Apr. 30, 2017	Jan. 31, 2017	Oct. 31, 2016	Jul. 31, 2016	Apr. 30, 2016	Jan. 31, 2018	Jan. 31, 2017	Jan. 31, 2016
Loss before income taxes is attributable to the following jurisdictions:
Domestic									$ (12,246)	$ (17,685)	$ (11,900)
Foreign									(7,913)	(13,654)	(15,859)
Loss before income taxes	$ (8,021)	$ (4,695)	$ (5,007)	$ (2,436)	$ (8,546)	$ (7,558)	$ (9,091)	$ (6,144)	(20,159)	(31,339)	(27,759)
Current:
Domestic									(225)	34	(16)
Foreign									1,156	846	684
Total									931	880	668
Deferred:
Domestic									(36)	40	10,762
Foreign									15	894	(453)
Total									(21)	934	10,309
Income tax expense	$ (262)	$ 586	$ 357	$ 229	$ 1,308	$ (228)	$ 435	$ 299	$ 910	$ 1,814	$ 10,977