Note 10 - Intangible Assets - Gross Carrying Amount and Accumulated Amortization of Intangible Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Finite-lived intangible assets, accumulated amortization	$ (3,269)	$ (3,214)
Finite-lived intangible assets, unamortized intangible assets	2,337
Goodwill, gross carrying amount	802	802
Goodwill, accumulated impairment	0	0
Goodwill	802	802
Intangible assets (including goodwill), gross carrying amount	6,408	6,344
Intangible assets, unamortized intangible assets	3,139	3,130
Mortgage Servicing Rights [Member]
Finite-lived intangible assets, gross carrying amount	5,032	4,968
Finite-lived intangible assets, accumulated amortization	(2,826)	(2,796)
Finite-lived intangible assets, unamortized intangible assets	2,206	2,172
Core Deposits [Member]
Finite-lived intangible assets, gross carrying amount	574	574
Finite-lived intangible assets, accumulated amortization	(443)	(418)
Finite-lived intangible assets, unamortized intangible assets	$ 131	$ 156