Note 7 - Fair Value - Assets Measured at Fair Value on a Recurring Basis (Details) - USD ($)	Mar. 31, 2022	Dec. 31, 2021
Securities - available-for-sale	$ 166,155,000	$ 186,270,000
Securities - equity investments	5,000	5,000
Fair Value, Inputs, Level 1 [Member]
Securities - available-for-sale	0	0
Securities - equity investments	5,000	5,000
Fair Value, Inputs, Level 2 [Member]
Securities - available-for-sale	161,570,000	182,685,000
Securities - equity investments	0	0
Fair Value, Inputs, Level 3 [Member]
Securities - available-for-sale	4,585,000	3,585,000
Securities - equity investments	0	0
US Government-sponsored Enterprises Debt Securities [Member]
Securities - available-for-sale	5,547,000	8,159,000
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	5,547,000	8,159,000
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	10,816,000	12,035,000
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	10,816,000	12,035,000
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	46,025,000	49,490,000
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	46,025,000	49,490,000
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	78,758,000	92,562,000
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	78,758,000	92,562,000
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	25,009,000	24,024,000
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	20,424,000	20,439,000
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Securities - available-for-sale	$ 4,585,000	$ 3,585,000