Segment Reporting - Additional Information (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
Schedule Of Sales Revenue By Business Segment [Line Items]
Revenues	$ 10,363	$ 8,644	$ 10,836	$ 18,433	$ 12,548	$ 8,057	$ 8,663	$ 11,731	$ 48,276	$ 40,999	$ 51,819
Reduction in capital expenditures and fixed assets										6	192
Eliminations
Schedule Of Sales Revenue By Business Segment [Line Items]
Revenues									$ 216	$ 62	$ 196