Note 2 - Summary of Significant Accounting Policies - Fair Value Measurements (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Summary of Significant Accounting Policies.
Other income recognized related to Coronavirus Aid, Relief and Economic Security Act Employee Retention Tax Credit	$ 5.4
Excess fair value of debt over carrying value	$ 35.5	$ 36.3