Note 21 - Revenue From Contracts With Customers - Noninterest Income (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
Noninterest income, financial service													$ 5,255	$ 4,966	$ 4,463
Net gains on loans and investments													528	1,439	1,355
Increase in cash value of life insurance													227	197	184
Other													158	96	167
Other noninterest income													913	1,732	1,706
Total noninterest income	$ 1,208	$ 1,698	$ 1,736	$ 1,526	$ 1,641	$ 1,748	$ 1,856	$ 1,453	$ 1,436	$ 1,750	$ 1,615	$ 1,368	6,168	6,698	6,169
Net gain (loss) on sales of foreclosed real estate													23	(3)	(30)
Deposit Account [Member]
Noninterest income, financial service													2,177	2,098	1,764
ATM and Debit Card Fees [Member]
Noninterest income, financial service													2,564	2,329	2,197
Investment Advisory, Management and Administrative Service [Member]
Noninterest income, financial service													386	416	384
Product and Service, Other [Member]
Noninterest income, financial service													$ 128	$ 123	$ 118