Note 14 - Financial Derivatives - Fair Value Swap Hedges (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Net unrealized loss		$ (3,478)	$ (3,171)	$ 1,525
Periodic net settlement of SWAPs	[1]	(7,719)	996
Interest Rate Swap [Member] | Designated as Hedging Instrument [Member] | Fair Value Hedging [Member]
Derivative, Notional Amount		$ 478,266	$ 579,584
Weighted average fixed rate-pay		4.56%	4.71%
Weighted average variable rate-receive		3.11%	4.87%
Net unrealized loss	[2]	$ (15,082)	$ (7,205)
Interest Rate Swap [Member] | Designated as Hedging Instrument [Member] | Fair Value Hedging [Member] | London Interbank Offered Rate (LIBOR) [Member]
Weighted average variable rate spread		2.46%	2.62%

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

[2] the amount is included in other non-interest income.