Note 4 - Qualified Affordable Housing Project Investment (Details Textual) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Investment Amortization	$ 87,000	$ 82,000	$ 169,000	$ 164,000
Tax Credits and Other Tax Benefits	123,000	$ 98,000	248,000	$ 196,000
Other Assets [Member]
Investments, Total	3,400,000		3,400,000		$ 3,600,000
Other Liabilities [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments	$ 2,500,000		$ 2,500,000		$ 2,900,000