Note 19 - Revenue From Contracts With Customers - Revenue by Operating Segment (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Non-interest income		$ 6,218	$ 5,439
Mortgage banking income	[1]	846	450
Bank owned life insurance	[1]	179	178
Other	[2]	280	506
Non-interest income		12,536	11,008
Commercial Banking [Member]
Non-interest income		0	0
Mortgage banking income	[1]	846	450
Bank owned life insurance	[1]	179	178
Other	[2]	280	506
Non-interest income		6,318	5,569
WM&T [Member]
Mortgage banking income	[1]	0	0
Bank owned life insurance	[1]	0	0
Other	[2]	0	0
Non-interest income		6,218	5,439
Fiduciary and Trust [Member]
Non-interest income		6,218	5,439
Fiduciary and Trust [Member] | Commercial Banking [Member]
Non-interest income		0	0
Fiduciary and Trust [Member] | WM&T [Member]
Non-interest income		6,218	5,439
Deposit Account [Member]
Non-interest income		1,283	1,178
Deposit Account [Member] | Commercial Banking [Member]
Non-interest income		1,283	1,178
Deposit Account [Member] | WM&T [Member]
Non-interest income		0	0
Credit and Debit Card [Member]
Non-interest income		1,980	1,744
Credit and Debit Card [Member] | Commercial Banking [Member]
Non-interest income		1,980	1,744
Credit and Debit Card [Member] | WM&T [Member]
Non-interest income		0	0
Treasury Management [Member]
Non-interest income		1,284	1,157
Treasury Management [Member] | Commercial Banking [Member]
Non-interest income		1,284	1,157
Treasury Management [Member] | WM&T [Member]
Non-interest income		0	0
Product Sales Commissions and Fees [Member]
Non-interest income		466	356
Product Sales Commissions and Fees [Member] | Commercial Banking [Member]
Non-interest income		466	356
Product Sales Commissions and Fees [Member] | WM&T [Member]
Non-interest income		$ 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.