Note 12 - 401(k) Savings Plan (Details Textual) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Defined Contribution Plan, Cost	$ 1.5	$ 1.4	$ 1.5
First 3% of Each Participant's Contributions [Member]
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay	100.00%
Second Two Percent Of Each Participants Contributions [Member]
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay	50.00%