Note 19 - Stock-based Compensation (Details Textual) - USD ($)		3 Months Ended	12 Months Ended
		Mar. 31, 2022	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2018	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized (in shares)						500,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant (in shares)			151,000
Proceeds (Used for) and Received from Settlement of Stock Awards			$ 175,000	$ 233,000
Common Stock, Capital Shares Reserved for Future Issuance (in shares)			106,000
Share-based Compensation Arrangement by Share-based Payment Award, Expected Shares to be Awarded (in shares)			111,000
Stock Appreciation Rights (SARs) [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant (in shares)	[1]		151,000
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period (Year)			10 years
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares)			29,000	34,000	30,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Non-Option Equity Instruments, Outstanding, Number (in shares)			440,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Outstanding, Exercise Price (in dollars per share)			$ 38.11
Stock Appreciation Rights (SARs) [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Outstanding, Exercise Price (in dollars per share)			19.44	$ 19.37	$ 15.24		$ 15.24
Stock Appreciation Rights (SARs) [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Outstanding, Exercise Price (in dollars per share)			$ 74.92	$ 74.92	$ 50.71		$ 40
Stock Appreciation Rights (SARs) [Member] | Share-Based Payment Arrangement, Tranche One [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage			20.00%
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)			5 years
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares)			38,000	35,000	39,000
Common Stock, Capital Shares Reserved for Future Issuance (in shares)			98,000
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)			3 years
Sharebased Compensation Arrangement by Share-based Payment Award Post Vesting Holding Period (Year)			1 year
Share-based Compensation Arrangement by Share-based Payment Award Liquidity Discount			5.20%	5.80%	6.10%
Performance Shares [Member] | Minimum [Member]
Common Stock, Capital Shares Reserved for Future Issuance (in shares)			0
Performance Shares [Member] | Maximum [Member]
Common Stock, Capital Shares Reserved for Future Issuance (in shares)			166,000
Restricted Stock Units (RSUs) [Member]
Common Stock, Capital Shares Reserved for Future Issuance (in shares)			8,000
Restricted Stock Units (RSUs) [Member] | Director [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)			12 months
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares)		5,410	8,668
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Fair Value Granted		$ 350,000	$ 550,000

[1] Under the 2015 Omnibus Equity Compensation Plan, shares of stock are authorized for issuance as incentive and non-qualified stock options, SARs, RSAs, and RSUs.