Note 6 - Goodwill and Other Intangible Assets (Details Textual) - USD ($)		3 Months Ended
	May 10, 2019	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	Dec. 31, 2018	May 10, 2018
Goodwill, Ending Balance		$ 1,107,000	$ 1,107,000	$ 1,107,000	$ 1,728,000
Goodwill, Purchase Accounting Adjustments			$ (621,000)
Goodwill, Impairment Loss		$ 0
Prime Bank [Member]
Goodwill, Ending Balance	$ 1,100,000				$ 1,700,000	$ 2,100,000
Goodwill, Purchase Accounting Adjustments	$ (621,000)
Business Acquisition, Goodwill, Tax Deductible Period (Year)	15 years