Portfolio Loans Not Covered by Loss Share ("Non-covered") - Summary of Non-covered Loans by Category (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	$ 2,085,872	$ 2,106,039
Non-Covered Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Portfolio Loans	2,085,428	2,106,028
Unearned loan costs, net	444	11
Total	2,085,872	2,106,039
Non-Covered Loans | Real Estate Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Portfolio Loans	1,116,538	1,126,178
Non-Covered Loans | Real Estate Loans | Construction and Land Development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Portfolio Loans	156,221	160,911
Non-Covered Loans | Real Estate Loans | Commercial Real Estate Investor Owned
Accounts, Notes, Loans and Financing Receivable [Line Items]
Portfolio Loans	473,003	486,467
Non-Covered Loans | Real Estate Loans | Commercial Real Estate Owner Occupied
Accounts, Notes, Loans and Financing Receivable [Line Items]
Portfolio Loans	339,086	333,242
Non-Covered Loans | Real Estate Loans | Residential Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Portfolio Loans	148,228	145,558
Non-Covered Loans | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Portfolio Loans	949,171	962,884
Non-Covered Loans | Consumer & other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Portfolio Loans	19,719	16,966
Total	$ 20,163	$ 16,977