Note 27 - Revenue From Contracts With Customers - Revenue by Operating Segment (Details) - USD ($) $ in Thousands		3 Months Ended												12 Months Ended
		Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Non-interest income														$ 22,643	$ 21,536	$ 20,505
Mortgage banking income	[1]													3,090	2,568	3,221
Bank owned life insurance	[1]													1,031	1,129	1,159
Other	[2]													2,900	1,337	1,769
Non-interest income		$ 13,161	$ 13,304	$ 12,263	$ 11,062	$ 11,576	$ 11,426	$ 11,435	$ 10,909	$ 11,407	$ 10,945	$ 11,525	$ 10,622	49,790	45,346	44,499
Loss on sale of securities														0	0	(232)
Commercial Banking [Member]
Non-interest income														0	0	0
Mortgage banking income	[1]													3,090	2,568	3,221
Bank owned life insurance	[1]													1,031	1,129	1,159
Other	[2]													2,900	1,337	1,769
Non-interest income														27,147	23,810	23,994
Loss on sale of securities																(232)
WM&T [Member]
Mortgage banking income	[1]													0	0	0
Bank owned life insurance	[1]													0	0	0
Other	[2]													0	0	0
Non-interest income														22,643	21,536	20,505
Loss on sale of securities																0
Fiduciary and Trust [Member]
Non-interest income														22,643	21,536	20,505
Fiduciary and Trust [Member] | Commercial Banking [Member]
Non-interest income														0	0	0
Fiduciary and Trust [Member] | WM&T [Member]
Non-interest income														22,643	21,536	20,505
Deposit Account [Member]
Non-interest income														5,513	5,759	6,172
Deposit Account [Member] | Commercial Banking [Member]
Non-interest income														5,513	5,759	6,172
Deposit Account [Member] | WM&T [Member]
Non-interest income														0	0	0
Credit and Debit Card [Member]
Non-interest income														8,123	6,769	5,979
Credit and Debit Card [Member] | Commercial Banking [Member]
Non-interest income														8,123	6,769	5,979
Credit and Debit Card [Member] | WM&T [Member]
Non-interest income														0	0	0
Treasury Management [Member]
Non-interest income														4,992	4,571	4,297
Treasury Management [Member] | Commercial Banking [Member]
Non-interest income														4,992	4,571	4,297
Treasury Management [Member] | WM&T [Member]
Non-interest income														0	0	0
Product Sales Commissions and Fees [Member]
Non-interest income														1,498	1,677	1,629
Product Sales Commissions and Fees [Member] | Commercial Banking [Member]
Non-interest income														1,498	1,677	1,629
Product Sales Commissions and Fees [Member] | WM&T [Member]
Non-interest income														$ 0	$ 0	$ 0

[1] Outside of the scope of ASC 606

[2] Outside of the scope of ASC 606, with the exception of safe deposit fees which were nominal for all periods.