Note 9 - Benefit Plans - Restricted Stock (Details) - Restricted Stock [Member]	3 Months Ended
	Mar. 31, 2019 $ / shares shares
Balance of shares non-vested (in shares) | shares	32,349
Balance of shares non-vested, weighted average grant-date price (in dollars per share) | $ / shares	$ 18.93
Granted (in shares) | shares	15,434
Granted, weighted average grant-date price (in dollars per share) | $ / shares	$ 23.85
Vested (in shares) | shares	(18,966)
Vested, weighted average grant-date price (in dollars per share) | $ / shares	$ 17.49
Forfeited (in shares) | shares
Forfeited, weighted average grant-date price (in dollars per share) | $ / shares
Balance of shares non-vested (in shares) | shares	28,817
Balance of shares non-vested, weighted average grant-date price (in dollars per share) | $ / shares	$ 22.52