Note 13 - Stock Based Compensation - Nonvested Restricted Stock Activity (Details) - Restricted Stock [Member]	6 Months Ended
	Jun. 30, 2020 $ / shares shares
Nonvested, shares (in shares) | shares	57,271
Nonvested, weighted average grant date value per share (in dollars per share) | $ / shares	$ 34.84
Granted, shares (in shares) | shares	19,327
Granted, weighted average grant date value per share (in dollars per share) | $ / shares	$ 37.26
Vested, shares (in shares) | shares	(18,580)
Vested, weighted average grant date value per share (in dollars per share) | $ / shares	$ 34.46
Forfeited, shares (in shares) | shares	(1,518)
Forfeited, weighted average grant date value per share (in dollars per share) | $ / shares	$ 32.25
Nonvested, shares (in shares) | shares	56,500
Nonvested, weighted average grant date value per share (in dollars per share) | $ / shares	$ 35.86