Revenue from Contracts with Customers - Revenue Disaggregation (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 31, 2021	Jul. 31, 2020	Jul. 31, 2021	Jul. 31, 2020
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	$ 6,807	$ 5,086	$ 11,001	$ 8,273
Revenue recognized at a point in time
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	6,662	4,885	10,725	7,872
Revenue recognized over time
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	145	201	276	401
Seamap | Revenue recognized at a point in time
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	5,256	3,881	8,169	5,870
Seamap | Revenue recognized over time
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	145	201	276	401
Klein | Revenue recognized at a point in time
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	$ 1,406	$ 1,004	$ 2,556	$ 2,002