Note 5 - Income Taxes - Summary of Operating Loss Carryforwards (Details) $ in Millions	12 Months Ended
	Mar. 31, 2025 USD ($) item
Operating Loss Carryforwards, Expiration Year	2,036
Tax Year 2014 [Member]
Operating Loss Carryforwards, Expiration Year | item	2,034
Tax Year 2016 [Member]
Operating Loss Carryforwards, Expiration Year | item	2,036
Tax Year 2017 [Member]
Operating Loss Carryforwards, Expiration Year | item	2,037
Tax Year 2018 [Member]
Operating Loss Carryforwards, Expiration Year | item	2,038
Tax Year 2019 [Member]
Operating Loss Carryforwards, Expiration Year | item	2,039
Tax Year 2020 [Member]
Operating Loss Carryforwards, Expiration Year | item	2,040
Tax Year 2021 [Member]
Operating Loss Carryforwards, Expiration Year | item	2,041
Tax Year 2022 [Member]
Operating Loss Carryforwards, Expiration Year | item	2,042
Tax Year 2024 [Member]
Operating Loss Carryforwards, Expiration Year | item	2,044
Tax Year 2025 [Member]
Operating Loss Carryforwards, Expiration Year	2,045
Domestic Tax Jurisdiction [Member]
Operating Loss Carryforwards	$ 19.1
Domestic Tax Jurisdiction [Member] | Tax Year 2014 [Member]
Operating Loss Carryforwards	0.0
Domestic Tax Jurisdiction [Member] | Tax Year 2016 [Member]
Operating Loss Carryforwards	0.0
Domestic Tax Jurisdiction [Member] | Tax Year 2017 [Member]
Operating Loss Carryforwards	0.0
Domestic Tax Jurisdiction [Member] | Tax Year 2018 [Member]
Operating Loss Carryforwards	0.0
Domestic Tax Jurisdiction [Member] | Tax Year 2019 [Member]
Operating Loss Carryforwards	1.9
Domestic Tax Jurisdiction [Member] | Tax Year 2020 [Member]
Operating Loss Carryforwards	3.7
Domestic Tax Jurisdiction [Member] | Tax Year 2021 [Member]
Operating Loss Carryforwards	4.0
Domestic Tax Jurisdiction [Member] | Tax Year 2022 [Member]
Operating Loss Carryforwards	3.4
Domestic Tax Jurisdiction [Member] | Tax Year 2024 [Member]
Operating Loss Carryforwards	2.4
Domestic Tax Jurisdiction [Member] | Tax Year 2025 [Member]
Operating Loss Carryforwards	3.7
State and Local Jurisdiction [Member]
Operating Loss Carryforwards	21.1
State and Local Jurisdiction [Member] | Tax Year 2014 [Member]
Operating Loss Carryforwards	0.0
State and Local Jurisdiction [Member] | Tax Year 2016 [Member]
Operating Loss Carryforwards	0.6
State and Local Jurisdiction [Member] | Tax Year 2017 [Member]
Operating Loss Carryforwards	0.8
State and Local Jurisdiction [Member] | Tax Year 2018 [Member]
Operating Loss Carryforwards	2.6
State and Local Jurisdiction [Member] | Tax Year 2019 [Member]
Operating Loss Carryforwards	2.7
State and Local Jurisdiction [Member] | Tax Year 2020 [Member]
Operating Loss Carryforwards	3.0
State and Local Jurisdiction [Member] | Tax Year 2021 [Member]
Operating Loss Carryforwards	3.2
State and Local Jurisdiction [Member] | Tax Year 2022 [Member]
Operating Loss Carryforwards	2.9
State and Local Jurisdiction [Member] | Tax Year 2024 [Member]
Operating Loss Carryforwards	2.1
State and Local Jurisdiction [Member] | Tax Year 2025 [Member]
Operating Loss Carryforwards	$ 3.2