Note 7 - Leases (Details Textual) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Finance Lease, Right-of-Use Asset, before Accumulated Amortization	$ 0.5		$ 0.5		$ 0.5
Right-of-Use Asset Obtained in Exchange for Finance Lease Liability	0.1	$ 0.1	0.1	$ 0.1
Property and Equipment [Member]
Finance Lease, Right-of-Use Asset, after Accumulated Amortization, Total	$ 0.3		$ 0.3		$ 0.2