Income Taxes - Reconciliation of Income Taxes by Jurisdiction (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Jan. 31, 2019	Oct. 31, 2018	Jul. 31, 2018	Apr. 30, 2018	Jan. 31, 2018	Oct. 31, 2017	Jul. 31, 2017	Apr. 30, 2017	Jan. 31, 2019	Jan. 31, 2018	Jan. 31, 2017
Loss before income taxes is attributable to the following jurisdictions:
Domestic									$ (6,025)	$ (12,246)	$ (17,685)
Foreign									(13,563)	(7,913)	(13,654)
Loss before income taxes	$ (4,176)	$ (5,440)	$ (4,504)	$ (5,468)	$ (8,021)	$ (4,695)	$ (5,007)	$ (2,436)	(19,588)	(20,159)	(31,339)
Current:
Domestic									9	(225)	34
Foreign									619	1,156	846
Total									628	931	880
Deferred:
Domestic									0	(36)	40
Foreign									(376)	15	894
Total									(376)	(21)	934
Income tax expense	$ (21)	$ (249)	$ 85	$ 437	$ (262)	$ 586	$ 357	$ 229	$ 252	$ 910	$ 1,814