Note 14 - Benefit Plans (Details Textual) - USD ($) $ in Millions	12 Months Ended				45 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2014	Dec. 31, 2021
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay				4.25%	5.00%
Defined Contribution Plan, Cost	$ 2.1	$ 1.9	$ 1.7
Interest Expense, Deferred Compensation Plan	$ 0.1	$ 0.1	$ 0.1
Stock Issued During Period, Shares, Employee Stock Purchase Plans (in shares)	1,481	2,264	1,507
Common Stock Including Additional Paid in Capital [Member]
Stock Issued During Period, Shares, Employee Stock Purchase Plans (in shares)	1,481	2,264
Stock Purchase Plan [Member]
Common Stock, Capital Shares Reserved for Future Issuance (in shares)	250,000				250,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant (in shares)	237,000				237,000
Other Liabilities [Member]
Deferred Compensation Liability, Current and Noncurrent, Total	$ 1.2	$ 2.4			$ 1.2