Acquisitions and Intangibles (Details) (USD $)	12 Months Ended			61 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Feb. 28, 2020	Feb. 01, 2015
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization of acquired intangible assets	$ 947,678	$ 1,262,524	$ 2,738,994
Debt Instrument, Term				5 years
Debt Instrument, Interest Rate, Stated Percentage					2.95%
Face amount	25,000,000
Mid-America Bancshares, Inc [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Number of bank owned by holding company	2
Period of amortization for remaining adjustment (in years)	3 years
Mid-America Bancshares, Inc [Member] | Core Deposits [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired finite-lived intangible asset	9,400,000
Amortization period of intangible assets (in years)	10 years
Amortization of acquired intangible assets	860,000	896,000	987,000
Mid-America Bancshares, Inc [Member] | Core Deposits [Member] | Minimum [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months	789,000
Finite-Lived Intangible Assets, Amortization Expense, Year Two	691,000
Finite-Lived Intangible Assets, Amortization Expense, Year Three	0
Mid-America Bancshares, Inc [Member] | Core Deposits [Member] | Maximum [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months	825,000
Finite-Lived Intangible Assets, Amortization Expense, Year Two	789,000
Finite-Lived Intangible Assets, Amortization Expense, Year Three	691,000
Cavalry Bancorp, Inc [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Number of bank owned by holding company	1
Cavalry Bancorp, Inc [Member] | Core Deposits [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired finite-lived intangible asset	13,200,000
Amortization period of intangible assets (in years)	7 years
Amortization of acquired intangible assets	0	273,000	1,600,000
Beach & Gentry Insurance LLC [Member] | Customer Lists [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired finite-lived intangible asset	1,270,000
Amortization period of intangible assets (in years)	20 years
Amortization of acquired intangible assets	90,701	96,748	102,794
Bankers Healthcare Group, LLC [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Face amount					40,000,000
Noncontrolling Interest, Ownership Percentage by Parent					30.00%
Purchase Price of Acquired Entity					75,000,000