Note 14 - Fair Value Measurements - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($)	Dec. 31, 2021	Dec. 31, 2020
Investment securities available for sale, at fair value	$ 344,212,000	$ 364,296,000
Fair Value, Recurring [Member]
Equity investments	3,071,000	1,260
Investments, Fair Value Disclosure, Total	347,283,000	365,556,000
Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member]
Equity investments	0	0
Investments, Fair Value Disclosure, Total	11,963,000	0
Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member]
Equity investments	3,071,000	1,260
Investments, Fair Value Disclosure, Total	335,320,000	356,644,000
Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member]
Equity investments	0	0
Investments, Fair Value Disclosure, Total	0	8,912,000
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Recurring [Member]
Investment securities available for sale, at fair value	113,364,000	127,862,000
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member]
Investment securities available for sale, at fair value	5,902,000	0
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member]
Investment securities available for sale, at fair value	107,462,000	127,862,000
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member]
Investment securities available for sale, at fair value	0	0
US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Recurring [Member]
Investment securities available for sale, at fair value	1,920,000
US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member]
Investment securities available for sale, at fair value	0
US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member]
Investment securities available for sale, at fair value	1,920,000
US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member]
Investment securities available for sale, at fair value	0
Asset-backed Securities, Issued by US Government Agencies [Member] | Fair Value, Recurring [Member]
Investment securities available for sale, at fair value		63,820,000
Asset-backed Securities, Issued by US Government Agencies [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member]
Investment securities available for sale, at fair value		0
Asset-backed Securities, Issued by US Government Agencies [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member]
Investment securities available for sale, at fair value		63,820,000
Asset-backed Securities, Issued by US Government Agencies [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member]
Investment securities available for sale, at fair value		0
Asset-backed Securities, Issued by Private Enterprises [Member] | Fair Value, Recurring [Member]
Investment securities available for sale, at fair value	14,489,000	29,280,000
Asset-backed Securities, Issued by Private Enterprises [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member]
Investment securities available for sale, at fair value	0	0
Asset-backed Securities, Issued by Private Enterprises [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member]
Investment securities available for sale, at fair value	14,489,000	29,280,000
Asset-backed Securities, Issued by Private Enterprises [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member]
Investment securities available for sale, at fair value	0	0
US Small Business Administration Securities [Member] | Fair Value, Recurring [Member]
Investment securities available for sale, at fair value	14,680,000	18,564,000
US Small Business Administration Securities [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member]
Investment securities available for sale, at fair value	0	0
US Small Business Administration Securities [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member]
Investment securities available for sale, at fair value	14,680,000	18,564,000
US Small Business Administration Securities [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member]
Investment securities available for sale, at fair value	0	0
Corporate Debt Securities [Member] | Fair Value, Recurring [Member]
Investment securities available for sale, at fair value	59,789,000	35,510,000
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member]
Investment securities available for sale, at fair value	6,061,000	0
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member]
Investment securities available for sale, at fair value	53,728,000	32,970,000
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member]
Investment securities available for sale, at fair value	0	2,540,000
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] | Fair Value, Recurring [Member]
Investment securities available for sale, at fair value	79,962,000	62,683,000
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member]
Investment securities available for sale, at fair value	0	0
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member]
Investment securities available for sale, at fair value	79,962,000	62,683,000
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member]
Investment securities available for sale, at fair value	0	0
Mortgage-backed Securities, Issued by Private Enterprises [Member] | Fair Value, Recurring [Member]
Investment securities available for sale, at fair value	60,008,000	26,577,000
Mortgage-backed Securities, Issued by Private Enterprises [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member]
Investment securities available for sale, at fair value	0	0
Mortgage-backed Securities, Issued by Private Enterprises [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member]
Investment securities available for sale, at fair value	60,008,000	20,205,000
Mortgage-backed Securities, Issued by Private Enterprises [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member]
Investment securities available for sale, at fair value	$ 0	$ 6,372,000