Purchase Credit Impaired ("PCI") Loans - Summary of PCI Loans by Category (Details) (Covered Loans, USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Covered Loans [Line Items]
Recorded Investment PCI Loans	$ 99,103	$ 140,538
Construction and Land Development
Covered Loans [Line Items]
Weighted- Average Risk Rating	6.16	6.84
Recorded Investment PCI Loans	7,740	14,325
Commercial Real Estate Investor Owned
Covered Loans [Line Items]
Weighted- Average Risk Rating	7.07	6.81
Recorded Investment PCI Loans	39,066	48,146
Commercial Real Estate Owner Occupied
Covered Loans [Line Items]
Weighted- Average Risk Rating	6.35	6.75
Recorded Investment PCI Loans	22,695	32,525
Residential Real Estate
Covered Loans [Line Items]
Weighted- Average Risk Rating	5.54	5.92
Recorded Investment PCI Loans	25,121	34,498
Total real estate loans
Covered Loans [Line Items]
Recorded Investment PCI Loans	94,622	129,494
Commercial & Industrial
Covered Loans [Line Items]
Weighted- Average Risk Rating	6.57	6.87
Recorded Investment PCI Loans	4,012	9,271
Consumer and other
Covered Loans [Line Items]
Weighted- Average Risk Rating	5.39	6.47
Recorded Investment PCI Loans	$ 469	$ 1,773