Note 17 - Parent Only Condensed Financial Statements - Condensed Statements of Income and Comprehensive Income (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Interest on junior subordinated deferrable interest debentures	$ 531,000	$ 510,000	$ 401,000
Interest on note payable			28,000
Other expenses	15,000	10,000	6,000
Total expenses	1,747,000	1,236,000	1,017,000
Income before equity in undistributed income of subsidiary	21,380,000	19,126,000	15,505,000
Provision for income taxes	5,868,000	5,134,000	7,316,000
Net income	15,512,000	13,992,000	8,189,000
Total comprehensive income	19,578,000	12,545,000	8,685,000
Parent Company [Member]
Dividends declared by bank subsidiary	2,800,000	2,000,000	4,000,000
Statutory Trusts I and II	16,000	15,000	12,000
Total income	2,816,000	2,015,000	4,012,000
Interest on junior subordinated deferrable interest debentures	531,000	510,000	401,000
Interest on note payable			28,000
Other expenses	315,000	326,000	251,000
Total expenses	846,000	836,000	680,000
Income before equity in undistributed income of subsidiary	1,970,000	1,179,000	3,332,000
Equity in undistributed income of subsidiary	13,261,000	12,479,000	4,538,000
Income before income taxes	15,231,000	13,658,000	7,870,000
Provision for income taxes	281,000	334,000	319,000
Net income	15,512,000	13,992,000	8,189,000
Total comprehensive income	$ 19,578,000	$ 12,545,000	$ 8,685,000