Note 4 - Loans and Allowance for Loan Losses - Recorded Investment of Residential and Consumer Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Loans receivable	$ 776,126	$ 777,052
Consumer Portfolio Segment [Member]
Loans receivable	141,276	143,370
Consumer Portfolio Segment [Member] | Automobile Loan [Member]
Loans receivable	66,696	70,226
Consumer Portfolio Segment [Member] | Home Equity Loan [Member]
Loans receivable	23,229	22,512
Consumer Portfolio Segment [Member] | Other Consumer Loans [Member]
Loans receivable	51,351	50,632
Residential Portfolio Segment [Member]
Loans receivable	311,040	304,079
Consumer and Residential Portfolio Segment [Member]
Loans receivable	452,316	447,449
Performing Financial Instruments [Member] | Consumer Portfolio Segment [Member] | Automobile Loan [Member]
Loans receivable	66,348	69,897
Performing Financial Instruments [Member] | Consumer Portfolio Segment [Member] | Home Equity Loan [Member]
Loans receivable	22,732	22,238
Performing Financial Instruments [Member] | Consumer Portfolio Segment [Member] | Other Consumer Loans [Member]
Loans receivable	51,143	50,318
Performing Financial Instruments [Member] | Residential Portfolio Segment [Member]
Loans receivable	303,496	297,399
Performing Financial Instruments [Member] | Consumer and Residential Portfolio Segment [Member]
Loans receivable	443,719	439,852
Nonperforming Financial Instruments [Member] | Consumer Portfolio Segment [Member] | Automobile Loan [Member]
Loans receivable	348	329
Nonperforming Financial Instruments [Member] | Consumer Portfolio Segment [Member] | Home Equity Loan [Member]
Loans receivable	497	274
Nonperforming Financial Instruments [Member] | Consumer Portfolio Segment [Member] | Other Consumer Loans [Member]
Loans receivable	208	314
Nonperforming Financial Instruments [Member] | Residential Portfolio Segment [Member]
Loans receivable	7,544	6,680
Nonperforming Financial Instruments [Member] | Consumer and Residential Portfolio Segment [Member]
Loans receivable	$ 8,597	$ 7,597