Portfolio Loans Covered by Loss Share (Covered loans) - Summary of Aging of the Recorded Investment in Past Due Covered Loans by Portfolio Class and Category (Details) (Covered Loans, USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	$ 6,204	$ 9,559
90 or More Days Past Due	37,614	58,665
Total Past Due	43,818	68,224
Current	177,615	232,386
Total	221,433	300,610
Commercial & Industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	3,325	879
90 or More Days Past Due	4,378	9,867
Total Past Due	7,703	10,746
Current	18,506	25,677
Total	26,209	36,423
Real Estate | Commercial - Owner Occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	0	1,438
90 or More Days Past Due	6,590	9,684
Total Past Due	6,590	11,122
Current	37,717	51,979
Total	44,307	63,101
Real Estate | Commercial - Investor Owned
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	375	2,530
90 or More Days Past Due	2,180	7,021
Total Past Due	2,555	9,551
Current	61,732	65,542
Total	64,287	75,093
Real Estate | Construction and Land Development
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	1,884	2,842
90 or More Days Past Due	21,830	28,745
Total Past Due	23,714	31,587
Current	14,906	34,403
Total	38,620	65,990
Real Estate | Residential
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	609	1,634
90 or More Days Past Due	2,634	3,341
Total Past Due	3,243	4,975
Current	43,183	51,853
Total	46,426	56,828
Consumer & Other
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	11	236
90 or More Days Past Due	2	7
Total Past Due	13	243
Current	1,571	2,932
Total	$ 1,584	$ 3,175