Note 9 - Revenue Recognition - Noninterest Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Noninterest Income (in-scope of Topic 606)			$ 4,687	$ 4,484
Noninterest Income (out-of-scope of Topic 606)			1,118	981
Total noninterest income	$ 1,914	$ 1,884	5,805	5,465
Deposit Account [Member]
Noninterest Income (in-scope of Topic 606)	673	710	2,037	2,067
Product and Service, Other [Member]
Noninterest Income (in-scope of Topic 606)	20	42	87	152
Credit and Debit Card [Member]
Noninterest Income (in-scope of Topic 606)	362	315	1,071	854
Fiduciary and Trust [Member]
Noninterest Income (in-scope of Topic 606)	$ 355	$ 365	1,131	1,127
Insurance and Investment [Member]
Noninterest Income (in-scope of Topic 606)			$ 361	$ 284