Note 10 - Intangible Assets - Gross Carrying Amount and Accumulated Amortization of Intangible Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Finite-lived intangible assets, accumulated amortization	$ (3,630)	$ (3,214)
Finite-lived intangible assets, unamortized intangible assets	2,962
Goodwill, gross carrying amount	802	802
Goodwill, accumulated impairment	0	0
Goodwill	802	802
Intangible assets (including goodwill), gross carrying amount	7,394	6,344
Intangible assets, unamortized intangible assets	3,764	3,130
Mortgage Servicing Rights [Member]
Finite-lived intangible assets, gross carrying amount	6,018	4,968
Finite-lived intangible assets, accumulated amortization	(3,138)	(2,796)
Finite-lived intangible assets, unamortized intangible assets	2,880	2,172
Core Deposits [Member]
Finite-lived intangible assets, gross carrying amount	574	574
Finite-lived intangible assets, accumulated amortization	(492)	(418)
Finite-lived intangible assets, unamortized intangible assets	$ 82	$ 156