Note 4 - Revenue Recognition - Reconciliation of the Cost in Excess of Billings (Details) - USD ($) $ in Thousands	Jan. 31, 2022	Jan. 31, 2021
Costs incurred on uncompleted contracts	$ 20,021	$ 17,543
Estimated earnings	12,030	9,651
Earned revenue	32,051	27,194
Less billings to date	31,019	23,949
Costs in excess of billings, net	1,032	3,245
Contract assets: Costs and estimated earnings in excess of billings on uncompleted contracts	2,309	4,007
Contract liabilities: Billings in excess of costs and estimated earnings on uncompleted contracts	$ (1,277)	$ (762)