Note 20 - Mergers and Acquisitions (Details Textual) - USD ($)		12 Months Ended
	Oct. 01, 2018	Dec. 31, 2019	Dec. 31, 2018	Sep. 30, 2018
Goodwill, Ending Balance		$ 19,460,000	$ 19,448,000
Amortization of Intangible Assets, Total		176,000	266,000
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months		164,000
Finite-Lived Intangible Assets, Amortization Expense, Year Two		154,000
Finite-Lived Intangible Assets, Amortization Expense, Year Three		149,000
Finite-Lived Intangible Assets, Amortization Expense, Year Four		149,000
Finite-Lived Intangible Assets, Amortization Expense, Year Five		149,000
Finite-Lived Intangible Assets, Amortization Expense, after Year Five		482,000
Community First [Member]
Payments to Acquire Businesses, Gross	$ 2,429,000
Goodwill, Ending Balance	9,172,000		9,200,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles	1,208,000
Business Acquisition, Goodwill, Expected Tax Deductible Amount	0
Business Combination, Acquired Receivable, Fair Value				$ 112,800,000
Business Combination, Loans Receivable, Credit Adjustment	1,700,000
Business Combination, Loans Receivable, Other Adjustment	441,000
Business Combination, Acquisition Related Costs			3,600,000
Community First [Member] | Employee Non-Compete and Severance Costs [Member]
Business Combination, Acquisition Related Costs			1,500,000
Community First [Member] | Professional Fees [Member]
Business Combination, Acquisition Related Costs			531,000
Community First [Member] | System Conversion Costs [Member]
Business Combination, Acquisition Related Costs			481,000
Community First [Member] | Contract Termination Fees [Member]
Business Combination, Acquisition Related Costs			427,000
Community First [Member] | Legal Fees [Member]
Business Combination, Acquisition Related Costs			330,000
Community First [Member] | Accounting and Auditing Fees [Member]
Business Combination, Acquisition Related Costs			50,000
Community First [Member] | Other Costs [Member]
Business Combination, Acquisition Related Costs			$ 228,000
Community First [Member] | Core Deposits [Member]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles	$ 1,200,000
Finite-Lived Intangible Asset, Useful Life	10 years
Amortization of Intangible Assets, Total		121,000
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months	$ 121,000
Finite-Lived Intangible Assets, Amortization Expense, Year Two		121,000
Finite-Lived Intangible Assets, Amortization Expense, Year Three		121,000
Finite-Lived Intangible Assets, Amortization Expense, Year Four		121,000
Finite-Lived Intangible Assets, Amortization Expense, Year Five		121,000
Finite-Lived Intangible Assets, Amortization Expense, after Year Five		$ 453,000
Community First [Member] | Common Stock [Member]
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares	419,173
Business Combination, Consideration Transferred, Equity Interests Issued and Issuable	$ 15,636,000
Business Combination, Step Acquisition, Equity Interest in Acquiree, Shares	18,000
Business Combination, Step Acquisition, Equity Interest in Acquiree, Gain on Retirement	$ 690,000
Community First [Member] | Preferred Stock [Member]
Business Combination, Consideration Transferred, Equity Interests Issued and Issuable	$ 4,206,000
Business Acquisition, Number of Shares Received	420,593
Business Acquisition, Number of Shares Received, Value	$ 4,200,000