Note 17 - Parent Only Condensed Financial Statements - Condensed Balance Sheets (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
ASSETS
Cash and cash equivalents	$ 46,942,000	$ 46,686,000	$ 87,537,000	$ 62,646,000
Total assets	865,191,000	824,398,000
LIABILITIES AND SHAREHOLDERS' EQUITY
Junior subordinated deferrable interest debentures	10,310,000	10,310,000
Total liabilities	780,686,000	757,466,000
Shareholders' equity:
Common stock - no par value; 22,500,000 shares authorized; issued and outstanding – 5,165,760 at December 31, 2019 and 5,137,476 at December 31, 2018	7,312,000	6,944,000
Retained earnings	75,144,000	62,005,000
Accumulated other comprehensive gain (loss), net of taxes	2,049,000	(2,017,000)
Total shareholders' equity	84,505,000	66,932,000	55,700,000	47,994,000
Total liabilities and shareholders' equity	865,191,000	824,398,000
Parent Company [Member]
ASSETS
Cash and cash equivalents	510,000	507,000	$ 383,000	$ 281,000
Investment in bank subsidiary	93,670,000	76,173,000
Other assets	658,000	602,000
Total assets	94,838,000	77,282,000
LIABILITIES AND SHAREHOLDERS' EQUITY
Other liabilities	23,000	40,000
Junior subordinated deferrable interest debentures	10,310,000	10,310,000
Total liabilities	10,333,000	10,350,000
Shareholders' equity:
Common stock - no par value; 22,500,000 shares authorized; issued and outstanding – 5,165,760 at December 31, 2019 and 5,137,476 at December 31, 2018	7,312,000	6,944,000
Retained earnings	75,144,000	62,005,000
Accumulated other comprehensive gain (loss), net of taxes	2,049,000	(2,017,000)
Total shareholders' equity	84,505,000	66,932,000
Total liabilities and shareholders' equity	$ 94,838,000	$ 77,282,000