Note 6 - Stock-Based Compensation (Details Textual)	3 Months Ended
	Mar. 31, 2022 USD ($) shares	Mar. 31, 2021 USD ($) shares
Number of Stock-based Compensation Plans in Effect	3
Share-Based Payment Arrangement, Expense | $	$ 10,000	$ 57,000
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total | $	$ 0
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period (in shares)	0
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)	0	0
The 2020 Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized (in shares)	200,000