Note 9 - Benefit Plans - Restricted Stock (Details) - Restricted Stock [Member]	6 Months Ended
	Jun. 30, 2020 $ / shares shares
Balance of shares non-vested (in shares) | shares	24,378
Balance of shares non-vested, weighted average grant-date price (in dollars per share) | $ / shares	$ 22.75
Granted (in shares) | shares	17,713
Granted, weighted average grant-date price (in dollars per share) | $ / shares	$ 21.84
Vested (in shares) | shares	(11,464)
Vested, weighted average grant-date price (in dollars per share) | $ / shares	$ 22.13
Forfeited (in shares) | shares	(1,732)
Forfeited, weighted average grant-date price (in dollars per share) | $ / shares	$ 23.04
Balance of shares non-vested (in shares) | shares	28,895
Balance of shares non-vested, weighted average grant-date price (in dollars per share) | $ / shares	$ 22.42