Note 7 - Fair Value - Assets Measured at Fair Value on a Non-recurring Basis (Details) - Fair Value, Nonrecurring [Member] - USD ($)	Jun. 30, 2021	Dec. 31, 2020
Other real estate owned	$ 0	$ 9,000
Total		407,000
Fair Value, Inputs, Level 1 [Member]
Other real estate owned		0
Total		0
Fair Value, Inputs, Level 2 [Member]
Other real estate owned		0
Total		0
Fair Value, Inputs, Level 3 [Member]
Other real estate owned		9,000
Total		407,000
Commercial Real Estate Portfolio Segment [Member]
Impaired loans	288,000	340,000
Commercial Real Estate Portfolio Segment [Member] | Fair Value, Inputs, Level 1 [Member]
Impaired loans	0	0
Commercial Real Estate Portfolio Segment [Member] | Fair Value, Inputs, Level 2 [Member]
Impaired loans	0	0
Commercial Real Estate Portfolio Segment [Member] | Fair Value, Inputs, Level 3 [Member]
Impaired loans	$ 288,000	340,000
Commercial Portfolio Segment [Member]
Impaired loans		58,000
Commercial Portfolio Segment [Member] | Fair Value, Inputs, Level 1 [Member]
Impaired loans		0
Commercial Portfolio Segment [Member] | Fair Value, Inputs, Level 2 [Member]
Impaired loans		0
Commercial Portfolio Segment [Member] | Fair Value, Inputs, Level 3 [Member]
Impaired loans		$ 58,000