Note 15 - Financial Derivatives - Cash Flow Swap Hedges (Details) - USD ($)		3 Months Ended		12 Months Ended
		Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Net unrealized gain (1)		$ (441,000)	$ 3,054,000
Interest Rate Swap [Member]
Notional		138,200,000
Interest Rate Swap [Member] | Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member]
Notional		$ 807,332,000		$ 874,034,000
Weighted average fixed rate-pay		1.92%		2.12%
Weighted average variable rate spread		0.44%		0.68%
Weighted average variable rate-receive		5.04%		2.61%
Net unrealized gain (1)		$ 29,815		$ 38,589
Periodic net settlement of swaps	[1]	$ 6,336,000	$ (1,762,000)

[1] the amount of periodic net settlement of interest rate swaps was included in interest expense.