Note 7 - Investment and Equity Securities - Gross Unrealized Losses and Fair Value (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Less than Twelve Months, Fair Value	$ 30,286	$ 6,991
Less than Twelve Months, Gross Unrealized Losses	(355)	(12)
Twelve Months or Greater, Fair Value	854	0
Twelve Months or Greater, Gross Unrealized Losses	(14)	0
Total, Fair Value	31,140	6,991
Total, Gross Unrealized Losses	(369)	(12)
Subordinated Debt Securities [Member]
Less than Twelve Months, Fair Value	6,149	4,243
Less than Twelve Months, Gross Unrealized Losses	(51)	(7)
Twelve Months or Greater, Fair Value	493	0
Twelve Months or Greater, Gross Unrealized Losses	(7)	0
Total, Fair Value	6,642	4,243
Total, Gross Unrealized Losses	(58)	(7)
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Less than Twelve Months, Fair Value	1,674	2,748
Less than Twelve Months, Gross Unrealized Losses	(53)	(5)
Twelve Months or Greater, Fair Value	361	0
Twelve Months or Greater, Gross Unrealized Losses	(7)	0
Total, Fair Value	2,035	2,748
Total, Gross Unrealized Losses	(60)	$ (5)
Nontaxable Municipal Bonds [Member]
Less than Twelve Months, Fair Value	22,463
Less than Twelve Months, Gross Unrealized Losses	(251)
Twelve Months or Greater, Fair Value	0
Twelve Months or Greater, Gross Unrealized Losses	0
Total, Fair Value	22,463
Total, Gross Unrealized Losses	$ (251)