Note 15 - Income Taxes - Net Operating Loss Carry Forwards and Tax Credit Carry Forwards Available to Offset Future Federal Income Tax (Details) $ in Thousands	Mar. 31, 2022 USD ($)
Operating Loss Carryforwards	$ 13,099
Research Tax Credit Carryforward [Member]
Research and Experimentation Tax Credits	28
State and Local Jurisdiction [Member]
Operating Loss Carryforwards	7,155
Expiration Tax Year 2023 [Member]
Operating Loss Carryforwards	1,478
Expiration Tax Year 2023 [Member] | Research Tax Credit Carryforward [Member]
Research and Experimentation Tax Credits	0
Expiration Tax Year 2023 [Member] | State and Local Jurisdiction [Member]
Operating Loss Carryforwards	0
Expiration Tax Year 2025 [Member]
Operating Loss Carryforwards	0
Expiration Tax Year 2025 [Member] | Research Tax Credit Carryforward [Member]
Research and Experimentation Tax Credits	8
Expiration Tax Year 2025 [Member] | State and Local Jurisdiction [Member]
Operating Loss Carryforwards	0
Expiration Tax Year 2026 [Member]
Operating Loss Carryforwards	159
Expiration Tax Year 2026 [Member] | Research Tax Credit Carryforward [Member]
Research and Experimentation Tax Credits	2
Expiration Tax Year 2026 [Member] | State and Local Jurisdiction [Member]
Operating Loss Carryforwards	0
Expiration Tax Year 2027 [Member]
Operating Loss Carryforwards	2,665
Expiration Tax Year 2027 [Member] | Research Tax Credit Carryforward [Member]
Research and Experimentation Tax Credits	0
Expiration Tax Year 2027 [Member] | State and Local Jurisdiction [Member]
Operating Loss Carryforwards	0
Expiration Tax Year After 2027 [Member]
Operating Loss Carryforwards	4,379
Expiration Tax Year After 2027 [Member] | Research Tax Credit Carryforward [Member]
Research and Experimentation Tax Credits	18
Expiration Tax Year After 2027 [Member] | State and Local Jurisdiction [Member]
Operating Loss Carryforwards	7,155
Indefinite [Member]
Operating Loss Carryforwards	4,418
Indefinite [Member] | Research Tax Credit Carryforward [Member]
Research and Experimentation Tax Credits	0
Indefinite [Member] | State and Local Jurisdiction [Member]
Operating Loss Carryforwards	$ 0