Note 9 - Benefit Plans - Restricted Stock (Details) - Restricted Stock [Member]	3 Months Ended
	Mar. 31, 2021 $ / shares shares
Balance of shares non-vested (in shares) | shares	28,037
Balance of shares non-vested, weighted average grant-date price (in dollars per share) | $ / shares	$ 21.80
Granted (in shares) | shares	20,126
Granted, weighted average grant-date price (in dollars per share) | $ / shares	$ 18.35
Vested (in shares) | shares	(9,599)
Vested, weighted average grant-date price (in dollars per share) | $ / shares	$ 22.20
Forfeited (in shares) | shares	0
Forfeited, weighted average grant-date price (in dollars per share) | $ / shares	$ 0
Balance of shares non-vested (in shares) | shares	38,564
Balance of shares non-vested, weighted average grant-date price (in dollars per share) | $ / shares	$ 19.90