Summary of Significant Accounting Policies (Details) - USD ($)			3 Months Ended		6 Months Ended		12 Months Ended
		Jan. 28, 2016	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015	Jul. 01, 2016
Cash Transactions [Abstract]
Interest paid					$ 14,722,572	$ 7,099,390
Income taxes paid, net					22,364,686	17,847,500
Noncash Transactions:
Loans charged-off to the allowance for loan losses					16,372,819	6,098,606	$ 21,148,000
Loans foreclosed upon and transferred to other real estate owned					2,464,945	252,896
Loans foreclosed upon and transferred to other assets					1,673,946	3,478,159
Basic net income per share calculation [Abstract]
Numerator - Net income			$ 30,786,772	$ 22,663,831	$ 58,752,036	$ 44,506,542
Denominator - Average common shares outstanding (in shares)			41,274,450	35,128,856	40,678,669	35,085,271
Basic net income per share (in dollars per share)			$ 0.75	$ 0.65	$ 1.44	$ 1.27
Diluted earnings per share calculation [Abstract]
Numerator - Net income			$ 30,786,772	$ 22,663,831	$ 58,752,036	$ 44,506,542
Denominator - Average common shares outstanding (in shares)			41,274,450	35,128,856	40,678,669	35,085,271
Dilutive shares contingently issuable (in shares)	[1]		700,033	425,827	732,579	391,827
Average diluted common shares outstanding (in shares)			41,974,483	35,554,683	41,411,248	35,477,098
Diluted net income per common share (in dollars per share)			$ 0.73	$ 0.64	$ 1.42	$ 1.25
Income Per Common Share [Abstract]
Shares excluded in weighted-average shares outstanding (in shares)			518,152
Mortgage Servicing Rights [Abstract]
Servicing Asset at Amortized Cost							6,400,000
Mortage servicing rights associated with Fannie Mae portfolio			$ 830,000,000
Sale of mortgage servicing rights			6,600,000
Income recorded upon sale of servicing portfolio			$ 241,000
Recently Adopted Accounting Pronouncements [Abstract]
Amount of deferred financing cost reclassified from other assets to subordinated debtAmount of deferred financing cost reclassified from other assets to subordinated debt							$ 870,000
Subordinated Notes [Member]
Business Acquisition [Line Items]
Debt maturity date					Jul. 25, 2016
Debt instrument, interest rate, stated percentage			4.875%		4.875%
Subordinated Notes [Member] | Three-Months LIBOR [Member]
Business Acquisition [Line Items]
Debt instrument, basis spread on variable rate					3.128%
Avenue Financial Holdings, Inc. (Avenue) [Member]
Business Acquisition [Line Items]
Shares of common stock issued to AVNU shareholders (in shares)		3,760,000
Cash provided to AVNU shareholders upon acquisition		$ 20,900,000
Cash provided to AVNU option holders upon acquisition		$ 1,000,000
Avenue Financial Holdings, Inc. (Avenue) [Member] | Common Stock [Member]
Business Acquisition [Line Items]
Fractional shares of common stock (in shares)		0.36
Business acquisition share price in cash (in dollars per share)		$ 2.00
Business acquisition, common shares issued and outstanding (in shares)								10,445,349
Business acquisition, outstanding stock options fully vested and exercisable (in shares)								101,389
Business combination, period for average closing price		10 days
Business acquisition, exercise price of stock options (in dollars per share)		$ 20.00
Avenue Financial Holdings, Inc. (Avenue) [Member] | Subordinated Notes [Member]
Business Acquisition [Line Items]
Business acquisition, assumed debt		$ 20,000,000
Debt maturity date		Dec. 14, 2016
Debt instrument, interest rate, stated percentage		6.75%
Avenue Financial Holdings, Inc. (Avenue) [Member] | Subordinated Notes [Member] | Three-Months LIBOR [Member]
Business Acquisition [Line Items]
Debt instrument, basis spread on variable rate		4.95%

[1] Approximately 518,152 restricted share units are not included in the weighted-average shares outstanding as they are deemed to be contingently issuable. Additionally, for the periods ending June 30, 2016 and 2015, there were no share-based awards excluded from the diluted earnings per share computation because they were deemed anti-dilutive.