Note 6 - Goodwill and Intangibles - Core Deposit Intangibles (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Balance at the beginning of period	$ 14,970	$ 17,450
Amortization expense	(2,149)	(2,266)	$ (1,692)
Balance at the end of the period	11,381	14,970	17,450
Net book value	14,970	17,450	17,450	$ 11,381	$ 14,970	$ 17,450
Core Deposits [Member]
Balance at the beginning of period	13,466	15,595	9,079
Amortization expense	(2,085)	(2,129)	(1,692)
Balance at the end of the period	11,381	13,466	15,595
Gross carrying amount				19,255	19,255	19,255
Accumulated amortization				(7,874)	(5,789)	(3,660)
Net book value	$ 11,381	$ 15,595	15,595	$ 11,381	$ 13,466	$ 15,595
Core Deposits [Member] | Springfield Bancshares
Merger			$ 8,208