Revenue from Contracts with Customers - Revenue Disaggregation (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2019	Jul. 31, 2018
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	$ 6,745	$ 6,012	$ 12,727	$ 9,720
Revenue recognized at a point in time
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	6,677	5,809	12,453	9,310
Revenue recognized over time
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	68	203	274	410
Seamap | Revenue recognized at a point in time
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	4,836	3,611	8,954	5,156
Seamap | Revenue recognized over time
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	68	203	274	410
Klein | Revenue recognized at a point in time
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	1,841	1,401	3,398	2,877
SAP | Revenue recognized at a point in time
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	$ 0	$ 797	$ 101	$ 1,277