Note 15 - Fair Values of Financial Instruments - Assets Measured at Fair Value on a Recurring Basis (Details) - USD ($)	Dec. 31, 2021	Dec. 31, 2020
Securities - available-for-sale	$ 186,270,000	$ 113,041,000
Securities - equity investments	5,000	15,000
Fair Value, Inputs, Level 1 [Member]
Securities - available-for-sale	0	0
Securities - equity investments	5,000	15,000
Fair Value, Inputs, Level 2 [Member]
Securities - available-for-sale	182,685,000	111,035,000
Securities - equity investments	0	0
Fair Value, Inputs, Level 3 [Member]
Securities - available-for-sale	3,585,000	2,006,000
Securities - equity investments	0	0
US Government-sponsored Enterprises Debt Securities [Member]
Securities - available-for-sale	8,159,000	3,007,000
US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Securities - available-for-sale	0	0
US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Securities - available-for-sale	8,159,000	3,007,000
US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Securities - available-for-sale	0	0
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Securities - available-for-sale	12,035,000	16,581,000
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] | Fair Value, Inputs, Level 1 [Member]
Securities - available-for-sale	0	0
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] | Fair Value, Inputs, Level 2 [Member]
Securities - available-for-sale	12,035,000	16,581,000
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] | Fair Value, Inputs, Level 3 [Member]
Securities - available-for-sale	0	0
Collateralized Mortgage Obligations [Member]
Securities - available-for-sale	49,490,000	15,911,000
Collateralized Mortgage Obligations [Member] | Fair Value, Inputs, Level 1 [Member]
Securities - available-for-sale	0	0
Collateralized Mortgage Obligations [Member] | Fair Value, Inputs, Level 2 [Member]
Securities - available-for-sale	49,490,000	15,911,000
Collateralized Mortgage Obligations [Member] | Fair Value, Inputs, Level 3 [Member]
Securities - available-for-sale	0	0
US States and Political Subdivisions Debt Securities [Member]
Securities - available-for-sale	92,562,000	55,577,000
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Securities - available-for-sale	0	0
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Securities - available-for-sale	92,562,000	55,577,000
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Securities - available-for-sale	0	0
Corporate Debt Securities [Member]
Securities - available-for-sale	24,024,000	21,965,000
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Securities - available-for-sale	0	0
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Securities - available-for-sale	20,439,000	19,959,000
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Securities - available-for-sale	$ 3,585,000	$ 2,006,000