Note 4 - Revenue Recognition - Reconciliation of the Cost in Excess of Billings (Details) - USD ($) $ in Thousands	Jan. 31, 2021	Jan. 31, 2020
Costs incurred on uncompleted contracts	$ 17,543	$ 15,553
Estimated earnings	9,651	8,641
Earned revenue	27,194	24,194
Less billings to date	23,949	23,201
Costs in excess of billings, net	3,245	993
Contract assets: Costs and estimated earnings in excess of billings on uncompleted contracts	4,007	2,166
Contract liabilities: Billings in excess of costs and estimated earnings on uncompleted contracts	$ (762)	$ (1,173)