Note 10 - Intangible Assets - Gross Carrying Amount and Accumulated Amortization of Intangible Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018
Finite-lived intangible assets, accumulated amortization	$ (3,187)		$ (2,906)
Finite-lived intangible assets, unamortized intangible assets	2,175
Goodwill, gross carrying amount	802		802
Goodwill, accumulated impairment	0		0
Goodwill	802	$ 802	802
Intangible assets (including goodwill), gross carrying amount	6,164		5,833
Intangible assets, unamortized intangible assets	2,977		2,927
Mortgage Servicing Rights [Member]
Finite-lived intangible assets, gross carrying amount	4,788		4,457
Finite-lived intangible assets, accumulated amortization	(2,794)		(2,612)
Finite-lived intangible assets, unamortized intangible assets	1,994		1,845
Core Deposits [Member]
Finite-lived intangible assets, gross carrying amount	574		574
Finite-lived intangible assets, accumulated amortization	(393)		(294)
Finite-lived intangible assets, unamortized intangible assets	$ 181		$ 280