Summary of Significant Accounting Policies (Details) (USD $)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Cash Transactions [Abstract]
Interest paid			$ 10,186,045	$ 12,434,753
Income taxes paid, net			22,150,000	20,850,009
Noncash Transactions:
Loans charged-off to the allowance for loan losses			5,634,327	14,088,656	17,252,000
Loans foreclosed upon and transferred to other real estate owned			1,672,459	3,491,421
Loans Foreclosed Upon And Transferred To Other Repossessed Assets			1,398,823	366,072
Available-for-sale securities transferred to held-to-maturity portfolio			0	39,959,647
Basic earnings per share calculation [Abstract]
Numerator - Net income available to common stockholders	18,196,822	14,646,950	51,733,929	42,405,607
Denominator - Average common shares outstanding (in shares)	34,762,206	34,282,899	34,688,064	34,148,562
Basic net income per share available to common stockholders (in dollars per share)	$ 0.52	$ 0.43	$ 1.49	$ 1.24
Diluted earnings per share calculation [Abstract]
Numerator - Net income available to common stockholders	$ 18,196,822	$ 14,646,950	$ 51,733,929	$ 42,405,607
Denominator - Average common shares outstanding (in shares)	34,762,206	34,282,899	34,688,064	34,148,562
Dilutive shares contingently issuable (in shares)	393,018	323,668	381,700	267,214
Average diluted common shares outstanding (in shares)	35,155,224	34,606,567	35,069,764	34,415,776
Diluted net income per share available to common stockholders (in dollars per share)	$ 0.52	$ 0.42	$ 1.48	$ 1.23