Note 16 - Financial Derivatives - Fair Value Swap Hedges (Details) - USD ($) $ in Thousands		3 Months Ended		12 Months Ended
		Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Net unrealized loss (1)		$ (4,278)	$ (1,224)
Periodic net settlement of SWAPs (2)	[1]	(643)	$ 613
Interest Rate Swap [Member] | Designated as Hedging Instrument [Member] | Fair Value Hedging [Member]
Derivative, Notional Amount		$ 561,854		$ 579,584
Weighted average fixed rate-pay		4.65%		4.71%
Weighted average variable rate-receive		4.16%		4.87%
Net unrealized loss (1)	[2]	$ (18,176)		$ (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		2.58%		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.