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Note 7 - Stock Plans (Details Textual) - $ / shares $ / shares in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2015	Dec. 31, 2023
Common Stock, No Par Value (in dollars per share)	$ 0			$ 0
Stock Settled Stock Appreciation Rights SSARs [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Non-Option Equity Instruments, Exercised (in shares)	(0)	0
The 2022 Stock Incentive Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized (in shares)	500,000
The 2022 Stock Incentive Plan [Member] \| Restricted Stock [Member] \| Vesting Each Year [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Rights, Percentage	33.00%
The 2022 Stock Incentive Plan [Member] \| Restricted Stock [Member] \| Award Date Three [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year)	1 year
The 2022 Stock Incentive Plan [Member] \| Restricted Stock [Member] \| Award Date Two [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year)	3 years
Long-Term Incentive Plan [Member] \| Stock Settled Stock Appreciation Rights SSARs [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Expiration Period (Year)			10 years
Long-Term Incentive Plan [Member] \| Restricted Stock [Member] \| New Employee [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)	12,429	17,684
The 2002 Employee Stock Purchase Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized (in shares)	165,000
Shares, Issued (in shares)	108,591