Portfolio Loans Not Covered by Loss Share ("Non-covered") - Summary of Recorded Investment in Non-covered Loans by Portfolio Class and Category Based on Impairment Method (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013	Jun. 30, 2014 Non-Covered Loans	Mar. 31, 2014 Non-Covered Loans	Dec. 31, 2013 Non-Covered Loans	Jun. 30, 2014 Non-Covered Loans Commercial & Industrial	Mar. 31, 2014 Non-Covered Loans Commercial & Industrial	Dec. 31, 2013 Non-Covered Loans Commercial & Industrial	Jun. 30, 2014 Non-Covered Loans Commercial Real Estate Owner Occupied	Mar. 31, 2014 Non-Covered Loans Commercial Real Estate Owner Occupied	Dec. 31, 2013 Non-Covered Loans Commercial Real Estate Owner Occupied	Jun. 30, 2014 Non-Covered Loans Commercial Real Estate Investor Owned	Mar. 31, 2014 Non-Covered Loans Commercial Real Estate Investor Owned	Dec. 31, 2013 Non-Covered Loans Commercial Real Estate Investor Owned	Jun. 30, 2014 Non-Covered Loans Construction and Land Development	Mar. 31, 2014 Non-Covered Loans Construction and Land Development	Dec. 31, 2013 Non-Covered Loans Construction and Land Development	Jun. 30, 2014 Non-Covered Loans Residential Real Estate	Mar. 31, 2014 Non-Covered Loans Residential Real Estate	Dec. 31, 2013 Non-Covered Loans Residential Real Estate	Jun. 30, 2014 Non-Covered Loans Consumer & Other	Mar. 31, 2014 Non-Covered Loans Consumer & Other	Dec. 31, 2013 Non-Covered Loans Consumer & Other
Summary of Recorded Investment in Non-covered Loans by Portfolio Class and Category Based on Impairment Method [Line Items]
Impaired Financing Receivable, Interest Income, Accrual Method	$ 6,000	$ 0	$ 15,000	$ 29,000
Allowance for Loan Losses - Ending Balance:
Individually evaluated for impairment						1,861,000		1,550,000	1,178,000		736,000	298,000		107,000	0		0	375,000		703,000	10,000		4,000	0		0
Collectively evaluated for impairment						26,561,000		25,739,000	13,897,000		11,510,000	3,723,000		3,989,000	4,330,000		6,600,000	1,780,000		1,433,000	2,517,000		2,015,000	314,000		192,000
Total						28,422,000	27,905,000	27,289,000	15,075,000	12,858,000	12,246,000	4,021,000	4,357,000	4,096,000	4,330,000	6,375,000	6,600,000	2,155,000	1,987,000	2,136,000	2,527,000	2,076,000	2,019,000	314,000	252,000	192,000
Loans - Ending Balance:
Individually evaluated for Impairment						22,065,000		20,840,000	4,649,000		3,380,000	4,276,000		606,000	5,174,000		6,811,000	7,422,000		9,484,000	544,000		559,000	0		0
Collectively evaluated for impairment						2,229,037,000		2,116,473,000	1,130,420,000		1,038,196,000	365,107,000		341,025,000	380,914,000		430,877,000	129,621,000		107,548,000	173,420,000		157,968,000	49,555,000		40,859,000
Total						2,250,023,000		2,136,292,000	1,135,069,000		1,041,576,000	369,383,000		341,631,000	386,088,000		437,688,000	137,043,000		117,032,000	173,964,000		158,527,000	48,476,000		39,838,000
Total	$ 2,251,102,000		$ 2,251,102,000		$ 2,137,313,000	$ 2,251,102,000		$ 2,137,313,000																$ 49,555,000		$ 40,859,000