Note 15 - Financial Derivatives - Cash Flow Swap Hedges (Details) - USD ($)		3 Months Ended		6 Months Ended		12 Months Ended
		Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Net change in unrealized holding (loss)/gain on cash flow hedge derivatives				$ (882,000)	$ 4,158,000
Interest Rate Swap [Member]
Notional		$ 6,100,000		6,100,000
Interest Rate Swap [Member] | Fair Value Hedging [Member] | Designated as Hedging Instrument [Member]
Notional		$ 758,655,000		$ 758,655,000		$ 874,034,000
Weighted average fixed rate-pay		1.82%		1.82%		2.12%
Weighted average variable rate spread		0.38%		0.38%		0.68%
Weighted average variable rate-receive		5.19%		5.19%		2.61%
Net change in unrealized holding (loss)/gain on cash flow hedge derivatives				$ 31,954		$ 38,589
Interest Rate Swap [Member] | Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member]
Notional						$ 50,000,000.0
Periodic net settlement of swaps	[1]	$ 7,070,000	$ 484,000	$ 13,406,000	$ 1,172,000

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