Note 20 - Parent Company Only Financial Statements - Condensed Balance Sheets (Details) - USD ($)	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash and due from banks	$ 70,569,993	$ 41,742,321
Interest-bearing deposits at financial institutions	63,948,925	36,313,965
Securities available for sale, at fair value	251,113,139	323,434,982
Premises and equipment, net	60,643,508	37,350,352
Other assets	37,503,284	26,784,392
Total assets	3,301,943,748	2,593,198,275	$ 2,524,958,100
Other borrowings	80,000,000	110,000,000
Other liabilities	55,690,087	42,484,573
Total liabilities	3,015,902,949	2,367,312,525
Common stock	13,106,845	11,761,083
Additional paid-in capital	156,776,642	123,282,851
Retained earnings	118,616,901	92,965,645
Total liabilities and stockholders' equity	3,301,943,748	2,593,198,275
Parent Company [Member]
Cash and due from banks	6,929,755	3,650,133
Interest-bearing deposits at financial institutions	651	701
Securities available for sale, at fair value	1,545,565	1,398,255
Premises and equipment, net	5,104,677	4,502,435
Other assets	15,245,521	12,797,292
Total assets	375,847,099	280,376,933
Other borrowings	35,000,000
Junior subordinated debentures	33,480,202	38,499,052
Other liabilities	21,326,098	15,992,131
Total liabilities	89,806,300	54,491,183
Common stock	13,106,845	11,761,083
Additional paid-in capital	156,776,642	123,282,851
Retained earnings	118,616,901	92,965,645
Accumulated other comprehensive loss	(2,459,589)	(2,123,829)
Total stockholders' equity	286,040,799	225,885,750
Total liabilities and stockholders' equity	375,847,099	280,376,933
Parent Company [Member] | Bank Subsidiaries [Member]
Investment in bank subsidiaries	345,866,288	256,709,890
Parent Company [Member] | Non-bank Subsidiaries [Member]
Investment in bank subsidiaries	$ 1,154,642	$ 1,318,227