Note 6 - Goodwill and Intangibles - Core Deposit Intangibles (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Balance at the beginning of period	$ 9,078,953	$ 7,381,213
Amortization expense	(1,692,431)	(1,000,561)	$ (442,850)
Balance at the end of the period	17,450,182	9,078,953	7,381,213
Net book value	9,078,953	7,381,213	7,381,213	$ 17,450,182	$ 9,078,953	$ 7,381,213
Core Deposits [Member]
Balance at the beginning of period	9,078,953	7,381,213	1,471,409
Amortization expense	(1,692,431)	(1,000,561)	(442,849)
Balance at the end of the period	15,595,250	9,078,953	7,381,213
Gross carrying amount				19,254,809	11,046,081	8,347,780
Accumulated amortization				(3,659,559)	(1,967,128)	(966,567)
Net book value	9,078,953	7,381,213	1,471,409	$ 15,595,250	$ 9,078,953	$ 7,381,213
Core Deposits [Member] | Springfield Bancshares
Core deposit intangible from acquisition	$ 8,208,728
Core Deposits [Member] | Guaranty Bank [Member]
Core deposit intangible from acquisition		$ 2,698,301
Core Deposits [Member] | Community State Bank [Member]
Core deposit intangible from acquisition			$ 6,352,653