Note 9 - Goodwill and Other Intangible Assets - Changes in Goodwill, by Reporting Unit (Details) - USD ($)	1 Months Ended	3 Months Ended	12 Months Ended
	Oct. 31, 2018	Sep. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Balance			$ 92,744,000
Impairment charges	$ (1,490,000)	$ (1,490,000)		$ (1,492,000)
Balance			129,565,000	92,744,000
Community Banking [Member]
Balance			92,744,000	95,779,000	95,779,000
Acquisitions and dispositions, net			36,821,000	(1,543,000)
Impairment charges				(1,492,000)
Balance			$ 129,565,000	$ 92,744,000	$ 95,779,000