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Note 6 - Goodwill and Intangibles - Goodwill (Details) - USD ($) $ in Thousands		1 Months Ended		3 Months Ended	12 Months Ended
	Nov. 30, 2020	Nov. 30, 2020	Nov. 30, 2019	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Balance at the beginning of period				$ 74,748	$ 74,748	$ 77,832	$ 28,334
Acquisition							49,741
Goodwill impairment	$ 0	$ 0			(500)	(3,000)
Balance at the end of period					74,066	74,748	77,832
Asset held-for-sale \| Bates Companies
Sale					(182)
Springfield Bancshares
Acquisition							45,975
Bates Companies
Acquisition							3,766
Acquisition - measurement period adjustment						(84)
Goodwill impairment			$ (3,000)	$ (500)	(500)	$ (3,000)
Balance at the end of period					$ 3,700
Guaranty Bank [Member]
Acquisition - measurement period adjustment							$ (243)