Note 7 - Restricted Investment in Stocks (Details Textual)	9 Months Ended
	Sep. 30, 2020 USD ($) shares	Dec. 31, 2019 USD ($)	Sep. 27, 2019
Investment Holdings [Line Items]
Restricted investment in stocks	$ 1,041,000	$ 1,073,000
Other than temporary impairment charge of restricted investment	0
Investment in Federal Home Loan Bank Stock [Member]
Investment Holdings [Line Items]
Restricted investment in stocks	1,029,000
Investment in Atlantic Community Bankers Bank Stock [Member]
Investment Holdings [Line Items]
Restricted investment in stocks	12,000
VISA Class B Stock [Member]
Investment Holdings [Line Items]
Restricted investment in stocks	$ 0
Number of shares owned | shares	6,502
VISA Class A Stock [Member]
Investment Holdings [Line Items]
Conversion factor per share			1.6228