Note 7 - Stock-based Compensation - Summary of Stock Option Activity (Details) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024	Dec. 31, 2023	Jan. 01, 2025	Jan. 01, 2024
Outstanding, stock options (in shares)	42,000	146,000			42,000	146,000
Outstanding, grant date weighted average exercise price (in dollars per share)	$ 2.74	$ 2.83			$ 2.74	$ 2.83
Outstanding, weighted average remaining contractual term (Year)	3 years 4 months 24 days	5 years 2 months 8 days	3 years 7 months 24 days	5 years 5 months 8 days
Outstanding, aggregate intrinsic value	$ 5,000	$ 5,000	$ 17,000	$ 0
Exercisable (in shares)	24,000	42,000
Exercisable, grant date weighted-average exercise price (in dollars per share)	$ 2.7	$ 2.86
Exercisable, weighted average remaining contractual life (Year)		3 years 10 months 2 days
Minimum [Member]
Exercisable, weighted average remaining contractual life (Year)	2 years 2 months 19 days