Note 20 - Disclosures About Fair Value of Financial Instruments - Carrying Value and Estimated Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Financial assets:
Securities available for sale	$ 261,841	$ 271,172
Equity securities (included in other assets)	1,715
Securities held to maturity		1
Fair Value, Inputs, Level 1 [Member]
Financial assets:
Equity securities (included in other assets)	1,715
Fair Value, Inputs, Level 2 [Member]
Financial assets:
Equity securities (included in other assets)
Fair Value, Inputs, Level 3 [Member]
Financial assets:
Equity securities (included in other assets)
Reported Value Measurement [Member]
Financial assets:
Cash and cash equivalents	41,112	25,915
Interest-bearing time deposits	7,710	9,258
Securities available for sale	261,841	271,172
Loans held for sale	2,849	2,630
Loans, net	434,260	409,618
FHLB and other restricted stock	1,988	1,979
Accrued interest receivable	2,828	2,694
Equity securities (included in other assets)	1,715
Securities held to maturity		1
Financial liabilities:
Deposits	701,646	664,562
Accrued interest payable	150	107
FHLB advances		10,000
Estimate of Fair Value Measurement [Member]
Financial assets:
Cash and cash equivalents	41,112	25,915
Interest-bearing time deposits	7,650	9,220
Securities available for sale	261,841	271,172
Loans held for sale	2,900	2,678
Loans, net	427,200	404,931
FHLB and other restricted stock
Accrued interest receivable	2,828	2,694
Equity securities (included in other assets)	1,715
Securities held to maturity		1
Financial liabilities:
Deposits	699,864	663,006
Accrued interest payable	150	107
FHLB advances		10,000
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member]
Financial assets:
Cash and cash equivalents	41,112	25,915
Interest-bearing time deposits
Securities available for sale
Loans held for sale
Loans, net
FHLB and other restricted stock
Accrued interest receivable
Equity securities (included in other assets)	1,715
Securities held to maturity
Financial liabilities:
Deposits
Accrued interest payable
FHLB advances
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member]
Financial assets:
Cash and cash equivalents
Interest-bearing time deposits	7,650	9,220
Securities available for sale	261,841	271,172
Loans held for sale	2,900	2,678
Loans, net
FHLB and other restricted stock
Accrued interest receivable	2,828	2,694
Equity securities (included in other assets)
Securities held to maturity		1
Financial liabilities:
Deposits
Accrued interest payable	150	107
FHLB advances		10,000
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 3 [Member]
Financial assets:
Cash and cash equivalents
Interest-bearing time deposits
Securities available for sale
Loans held for sale
Loans, net	427,200	404,931
FHLB and other restricted stock
Accrued interest receivable
Equity securities (included in other assets)
Securities held to maturity
Financial liabilities:
Deposits	699,864	663,006
Accrued interest payable
FHLB advances