Note 5 - Goodwill and Intangible Assets - Changes in the Net Carrying Amount of Core Deposit Intangibles (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Balance at beginning of period			$ 1,057
Balance at end of period	$ 2,373		2,373
Core Deposits [Member]
Balance at beginning of period	2,461	$ 1,139	1,056	$ 1,225
Core deposit intangible acquired	0	0	1,519	0
Amortization	(88)	(41)	(202)	(127)
Balance at end of period	$ 2,373	$ 1,098	$ 2,373	$ 1,098