Note 8 - Leases - Lease Modifications (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2022	Mar. 31, 2022
Total	$ 5,422
Operating Lease, Right-of-Use Asset	4,987		$ 5,770
Environmental Technologies in Germany [Member]
Total	90	$ 90
Operating Lease, Right-of-Use Asset	90	$ 90
Lease Facility in Singapore [Member]
Total			51		$ 51
Operating Lease, Right-of-Use Asset			51		$ 51
Automobile Lease, One [Member]
Total	30
Operating Lease, Right-of-Use Asset	30
Automobile Lease for Videology [Member]
Total			42	$ 42
Operating Lease, Right-of-Use Asset			42	$ 42
Automobile Lease, Two [Member]
Total	41
Operating Lease, Right-of-Use Asset	41
Facility for Acculogic Operation in Canada [Member]
Total			942
Operating Lease, Right-of-Use Asset			942
Southeast Asia Operation [Member]
Total	455
Operating Lease, Right-of-Use Asset	455
Facility for Acculogic Operation in California [Member]
Total			127
Operating Lease, Right-of-Use Asset			$ 127
Process Technologies in the Netherlands [Member]
Total	136
Operating Lease, Right-of-Use Asset	$ 136