Consolidated Balance Sheets - USD ($)	Jun. 30, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Cash and due from banks	$ 69,069,403	$ 75,721,663
Federal funds sold	10,866,000	30,197,000
Interest-bearing deposits at financial institutions	40,801,388	55,765,012
Securities held to maturity, at amortized cost	400,052,344	379,474,205
Securities available for sale, at fair value	257,944,671	272,907,907
Total securities	657,997,015	652,382,112
Loans receivable held for sale	1,033,700	645,001
Loans/leases receivable held for investment	3,113,758,723	2,963,840,399
Gross loans/leases receivable	3,114,792,423	2,964,485,400
Less allowance for estimated losses on loans/leases	(37,545,076)	(34,355,728)
Net loans/leases receivable	3,077,247,347	2,930,129,672
Bank-owned life insurance	59,876,754	59,059,494
Premises and equipment, net	64,472,319	62,838,255
Restricted investment securities	23,888,600	19,782,525
Other real estate owned, net	12,750,023	13,558,308
Goodwill	28,090,897	28,334,092
Core deposit intangible	8,469,851	9,078,953
Other assets	53,353,108	45,817,687
Total assets	4,106,882,705	3,982,664,773
Liabilities and Stockholders' Equity
Noninterest-bearing	746,821,779	789,547,696
Interest-bearing	2,551,454,248	2,477,107,360
Total deposits	3,298,276,027	3,266,655,056
Short-term borrowings	17,585,605	13,993,122
Federal Home Loan Bank advances	254,100,000	192,000,000
Other borrowings	71,125,000	66,000,000
Junior subordinated debentures	37,580,881	37,486,487
Other liabilities	58,627,027	53,242,979
Total liabilities	3,737,294,540	3,629,377,644
Stockholders' Equity:
Common stock, $1 par value; shares authorized 20,000,000 June 2018 - 13,973,940 shares issued and outstanding December 2017 - 13,918,168 shares issued and outstanding	13,973,940	13,918,168
Additional paid-in capital	190,533,240	189,077,550
Retained earnings	171,955,296	151,962,661
Accumulated other comprehensive loss:
Securities available for sale	(6,058,893)	(866,223)
Derivatives	(815,418)	(805,027)
Total stockholders' equity	369,588,165	353,287,129
Total liabilities and stockholders' equity	$ 4,106,882,705	$ 3,982,664,773