Note 11 - Stock-based Compensation Plans - Stock Options Outstanding and Exercisable (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Lower Range of Exercise Price (in dollars per share)	$ 3.5
Upper Range of Exercise Price (in dollars per share)	$ 39.11
Number Outstanding (in shares)	59,000	59,000	59,000
Outstanding Weighted Average Contractual Life Remaining (Year)	3 years 7 months 6 days
Outstanding Weighted Average Exercise Price (in dollars per share)	$ 17.35
Outstanding Aggregate Intrinsic Value	$ 394,840
Options Outstanding Exercise Price Range1 [Member]
Lower Range of Exercise Price (in dollars per share)	$ 3.5
Upper Range of Exercise Price (in dollars per share)	$ 3.86
Number Outstanding (in shares)	13,000
Outstanding Weighted Average Contractual Life Remaining (Year)	2 years 2 months 12 days
Outstanding Weighted Average Exercise Price (in dollars per share)	$ 3.75
Outstanding Aggregate Intrinsic Value	$ 233,100
Options Outstanding Exercise Price Range2 [Member]
Lower Range of Exercise Price (in dollars per share)	$ 7.8
Number Outstanding (in shares)	8,000
Outstanding Weighted Average Contractual Life Remaining (Year)	3 years 4 months 24 days
Outstanding Weighted Average Exercise Price (in dollars per share)	$ 7.8
Outstanding Aggregate Intrinsic Value	$ 11,040
Options Outstanding Exercise Price Range 3 [Member]
Lower Range of Exercise Price (in dollars per share)	$ 19.99
Number Outstanding (in shares)	30,000
Outstanding Weighted Average Contractual Life Remaining (Year)	4 years 1 month 6 days
Outstanding Weighted Average Exercise Price (in dollars per share)	$ 19.99
Outstanding Aggregate Intrinsic Value	$ 50,700
Options Outstanding Exercise Price Range 4 [Member]
Lower Range of Exercise Price (in dollars per share)	$ 39.11
Number Outstanding (in shares)	8,000
Outstanding Weighted Average Contractual Life Remaining (Year)	4 years 4 months 24 days
Outstanding Weighted Average Exercise Price (in dollars per share)	$ 39.11
Outstanding Aggregate Intrinsic Value	$ 0