Note 9 - Goodwill and Other Intangible Assets (Details Textual)	1 Months Ended	3 Months Ended	12 Months Ended
	Oct. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Number of Reportable Segments			1
Goodwill, Impairment Loss	$ 1,490,000	$ 1,490,000		$ 1,492,000
Amortization of Intangible Assets, Total			$ 997,000	$ 1,039,000	$ 1,056,000
Core Deposits [Member]
Finite-Lived Intangible Assets, Remaining Amortization Period			7 years
Minimum [Member] | Core Deposits [Member]
Finite-Lived Intangible Asset, Useful Life			3 years
Maximum [Member] | Core Deposits [Member]
Finite-Lived Intangible Asset, Useful Life			10 years