Note 27 - Revenue From Contracts With Customers - Revenue by Operating Segment (Details) - USD ($) $ in Thousands		3 Months Ended												12 Months Ended
		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, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Non-interest income														$ 23,810	$ 23,994	$ 23,765
Total non-interest income		$ 11,576	$ 11,426	$ 11,435	$ 10,909	$ 11,407	$ 10,945	$ 11,525	$ 10,622	$ 11,165	$ 11,202	$ 10,629	$ 9,924	45,346	44,499	42,920
Fiduciary and Trust [Member]
Non-interest income														21,536	20,505	19,155
Deposit Account [Member]
Non-interest income														5,759	6,172	6,037
Credit and Debit Card [Member]
Non-interest income														6,769	5,979	5,655
Treasury Management [Member]
Non-interest income														4,571	4,297	3,867
Mortgage Banking [Member]
Non-interest income	[1]													2,568	3,221	3,897
Sales of Securities Available for Sale [Member]
Non-interest income	[1]														(232)
Product Sales Commissions and Fees [Member]
Non-interest income														1,677	1,629	1,563
Bank Owned Life Insurance [Member]
Non-interest income	[1]													1,129	1,159	871
Product and Service, Other [Member]
Non-interest income	[2]													$ 1,337	$ 1,769	$ 1,875

[1] Not within scope of ASC 606

[2] Includes safe box deposit fees of $177 thousand, $165 thousand, and $168 thousand included within the scope of ASC 606 in 2018, 2017, and 2016, respectively