Note 21 - Revenue From Contracts With Customers - Revenue by Operating Segment (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Non-interest income		$ 5,738	$ 5,380	$ 16,839	$ 16,224
Mortgage banking income	[1]	834	712	2,112	2,034
Bank owned life insurance	[1]	487	186	849	564
Other	[2]	1,035	312	2,045	1,096
Non-interest income		13,304	11,426	36,629	33,770
Gain on sale of securities				0	0
Commercial Banking [Member]
Non-interest income		0	0	0	0
Mortgage banking income	[1]	834	712	2,112	2,034
Bank owned life insurance	[1]	487	186	849	564
Other	[2]	1,035	312	2,045	1,096
Non-interest income		7,566	6,046	19,790	17,546
Gain on sale of securities				0	0
WM&T [Member]
Mortgage banking income	[1]	0	0	0	0
Bank owned life insurance	[1]	0	0	0	0
Other	[2]	0	0	0	0
Non-interest income		5,738	5,380	16,839	16,224
Gain on sale of securities				0	0
Fiduciary and Trust [Member]
Non-interest income		5,738	5,380	16,839	16,224
Fiduciary and Trust [Member] | Commercial Banking [Member]
Non-interest income		0	0	0	0
Fiduciary and Trust [Member] | WM&T [Member]
Non-interest income		5,738	5,380	16,839	16,224
Deposit Account [Member]
Non-interest income		1,444	1,482	4,027	4,340
Deposit Account [Member] | Commercial Banking [Member]
Non-interest income		1,444	1,482	4,027	4,340
Deposit Account [Member] | WM&T [Member]
Non-interest income		0	0	0	0
Credit and Debit Card [Member]
Non-interest income		2,102	1,759	6,014	4,956
Credit and Debit Card [Member] | Commercial Banking [Member]
Non-interest income		2,102	1,759	6,014	4,956
Credit and Debit Card [Member] | WM&T [Member]
Non-interest income		0	0	0	0
Treasury Management [Member]
Non-interest income		1,264	1,151	3,623	3,311
Treasury Management [Member] | Commercial Banking [Member]
Non-interest income		1,264	1,151	3,623	3,311
Treasury Management [Member] | WM&T [Member]
Non-interest income		0	0	0	0
Product Sales Commissions and Fees [Member]
Non-interest income		400	444	1,120	1,245
Product Sales Commissions and Fees [Member] | Commercial Banking [Member]
Non-interest income		400	444	1,120	1,245
Product Sales Commissions and Fees [Member] | WM&T [Member]
Non-interest income		$ 0	$ 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.