Note 4 - Loans and Allowance for Loan Losses - Past Due Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Loans past due	$ 14,647	$ 12,190
Loans, current	761,479	764,862
Loans	776,126	777,052
Commercial real estate:
Loans past due	14,647	12,190
Loans, current	761,479	764,862
Loans	776,126	777,052
Consumer:
Loans past due	14,647	12,190
Loans, current	761,479	764,862
Loans	776,126	777,052
Residential Portfolio Segment [Member]
Loans past due	7,893	6,194
Loans, current	303,147	297,885
Loans	311,040	304,079
Commercial real estate:
Loans past due	7,893	6,194
Loans, current	303,147	297,885
Loans	311,040	304,079
Consumer:
Loans past due	7,893	6,194
Loans, current	303,147	297,885
Loans	311,040	304,079
Commercial Real Estate Portfolio Segment [Member]
Loans	221,514	216,360
Commercial real estate:
Loans	221,514	216,360
Consumer:
Loans	221,514	216,360
Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Owner Occupied [Member]
Loans past due	354	427
Loans, current	59,461	61,267
Loans	59,815	61,694
Commercial real estate:
Loans past due	354	427
Loans, current	59,461	61,267
Loans	59,815	61,694
Consumer:
Loans past due	354	427
Loans, current	59,461	61,267
Loans	59,815	61,694
Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Nonowner Occupied [Member]
Loans past due	857	1,046
Loans, current	128,678	116,142
Loans	129,535	117,188
Commercial real estate:
Loans past due	857	1,046
Loans, current	128,678	116,142
Loans	129,535	117,188
Consumer:
Loans past due	857	1,046
Loans, current	128,678	116,142
Loans	129,535	117,188
Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Loans past due	159	296
Loans, current	32,005	37,182
Loans	32,164	37,478
Commercial real estate:
Loans past due	159	296
Loans, current	32,005	37,182
Loans	32,164	37,478
Consumer:
Loans past due	159	296
Loans, current	32,005	37,182
Loans	32,164	37,478
Commercial and Industrial Portfolio Segment [Member]
Loans past due	1,661	730
Loans, current	100,635	112,513
Loans	102,296	113,243
Commercial real estate:
Loans past due	1,661	730
Loans, current	100,635	112,513
Loans	102,296	113,243
Consumer:
Loans past due	1,661	730
Loans, current	100,635	112,513
Loans	102,296	113,243
Consumer Portfolio Segment [Member]
Loans	141,276	143,370
Commercial real estate:
Loans	141,276	143,370
Consumer:
Loans	141,276	143,370
Consumer Portfolio Segment [Member] | Automobile Loan [Member]
Loans past due	1,842	1,862
Loans, current	64,854	68,364
Loans	66,696	70,226
Commercial real estate:
Loans past due	1,842	1,862
Loans, current	64,854	68,364
Loans	66,696	70,226
Consumer:
Loans past due	1,842	1,862
Loans, current	64,854	68,364
Loans	66,696	70,226
Consumer Portfolio Segment [Member] | Home Equity Loan [Member]
Loans past due	825	523
Loans, current	22,404	21,989
Loans	23,229	22,512
Commercial real estate:
Loans past due	825	523
Loans, current	22,404	21,989
Loans	23,229	22,512
Consumer:
Loans past due	825	523
Loans, current	22,404	21,989
Loans	23,229	22,512
Consumer Portfolio Segment [Member] | Other Consumer Loans [Member]
Loans past due	1,056	1,112
Loans, current	50,295	49,520
Loans	51,351	50,632
Commercial real estate:
Loans past due	1,056	1,112
Loans, current	50,295	49,520
Loans	51,351	50,632
Consumer:
Loans past due	1,056	1,112
Loans, current	50,295	49,520
Loans	51,351	50,632
Financial Asset, 30 to 59 Days Past Due [Member]
Loans past due	7,840	6,476
Commercial real estate:
Loans past due	7,840	6,476
Consumer:
Loans past due	7,840	6,476
Financial Asset, 30 to 59 Days Past Due [Member] | Residential Portfolio Segment [Member]
Loans past due	4,651	3,369
Commercial real estate:
Loans past due	4,651	3,369
Consumer:
Loans past due	4,651	3,369
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Owner Occupied [Member]
Loans past due	198	298
Commercial real estate:
Loans past due	198	298
Consumer:
Loans past due	198	298
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Nonowner Occupied [Member]
Loans past due	229	299
Commercial real estate:
Loans past due	229	299
Consumer:
Loans past due	229	299
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Loans past due	159	31
Commercial real estate:
Loans past due	159	31
Consumer:
Loans past due	159	31
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial and Industrial Portfolio Segment [Member]
Loans past due	160	428
Commercial real estate:
Loans past due	160	428
Consumer:
Loans past due	160	428
Financial Asset, 30 to 59 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Automobile Loan [Member]
Loans past due	1,384	1,287
Commercial real estate:
Loans past due	1,384	1,287
Consumer:
Loans past due	1,384	1,287
Financial Asset, 30 to 59 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Home Equity Loan [Member]
Loans past due	342	171
Commercial real estate:
Loans past due	342	171
Consumer:
Loans past due	342	171
Financial Asset, 30 to 59 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Other Consumer Loans [Member]
Loans past due	717	593
Commercial real estate:
Loans past due	717	593
Consumer:
Loans past due	717	593
Financial Asset, 60 to 89 Days Past Due [Member]
Loans past due	2,194	2,044
Commercial real estate:
Loans past due	2,194	2,044
Consumer:
Loans past due	2,194	2,044
Financial Asset, 60 to 89 Days Past Due [Member] | Residential Portfolio Segment [Member]
Loans past due	782	1,183
Commercial real estate:
Loans past due	782	1,183
Consumer:
Loans past due	782	1,183
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Owner Occupied [Member]
Loans past due	156
Commercial real estate:
Loans past due	156
Consumer:
Loans past due	156
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Nonowner Occupied [Member]
Loans past due	338
Commercial real estate:
Loans past due	338
Consumer:
Loans past due	338
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Loans past due
Commercial real estate:
Loans past due
Consumer:
Loans past due
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial and Industrial Portfolio Segment [Member]
Loans past due	435	192
Commercial real estate:
Loans past due	435	192
Consumer:
Loans past due	435	192
Financial Asset, 60 to 89 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Automobile Loan [Member]
Loans past due	198	286
Commercial real estate:
Loans past due	198	286
Consumer:
Loans past due	198	286
Financial Asset, 60 to 89 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Home Equity Loan [Member]
Loans past due	72	92
Commercial real estate:
Loans past due	72	92
Consumer:
Loans past due	72	92
Financial Asset, 60 to 89 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Other Consumer Loans [Member]
Loans past due	213	291
Commercial real estate:
Loans past due	213	291
Consumer:
Loans past due	213	291
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans past due	4,613	3,670
Commercial real estate:
Loans past due	4,613	3,670
Consumer:
Loans past due	4,613	3,670
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Residential Portfolio Segment [Member]
Loans past due	2,460	1,642
Commercial real estate:
Loans past due	2,460	1,642
Consumer:
Loans past due	2,460	1,642
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Owner Occupied [Member]
Loans past due		129
Commercial real estate:
Loans past due		129
Consumer:
Loans past due		129
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Nonowner Occupied [Member]
Loans past due	290	747
Commercial real estate:
Loans past due	290	747
Consumer:
Loans past due	290	747
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Loans past due		265
Commercial real estate:
Loans past due		265
Consumer:
Loans past due		265
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial and Industrial Portfolio Segment [Member]
Loans past due	1,066	110
Commercial real estate:
Loans past due	1,066	110
Consumer:
Loans past due	1,066	110
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Automobile Loan [Member]
Loans past due	260	289
Commercial real estate:
Loans past due	260	289
Consumer:
Loans past due	260	289
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Home Equity Loan [Member]
Loans past due	411	260
Commercial real estate:
Loans past due	411	260
Consumer:
Loans past due	411	260
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Other Consumer Loans [Member]
Loans past due	126	228
Commercial real estate:
Loans past due	126	228
Consumer:
Loans past due	$ 126	$ 228