Portfolio Loans Not Covered by Loss Share ("Non-covered") - Summary of Non-covered Loans Individually Evaluated for Impairment by Category (Details) (Non-Covered Loans, USD $) In Thousands, unless otherwise specified	9 Months Ended	12 Months Ended
	Sep. 30, 2012	Dec. 31, 2011
Financing Receivable, Impaired [Line Items]
Unpaid Contractual Principal Balance	$ 41,644	$ 54,442
Recorded Investment With No Allowance	7,484	4,881
Recorded Investment With Allowance	24,574	36,741
Total Recorded Investment	32,058	41,622
Related Allowance	6,787	10,729
Average Recorded Investment	40,863	45,546
Commercial & Industrial
Financing Receivable, Impaired [Line Items]
Unpaid Contractual Principal Balance	4,081	7,517
Recorded Investment With No Allowance	291	128
Recorded Investment With Allowance	2,558	5,506
Total Recorded Investment	2,849	5,634
Related Allowance	1,165	3,214
Average Recorded Investment	6,322	6,571
Real Estate | Commercial - Owner Occupied
Financing Receivable, Impaired [Line Items]
Unpaid Contractual Principal Balance	6,154	5,099
Recorded Investment With No Allowance	2,875	0
Recorded Investment With Allowance	2,709	4,572
Total Recorded Investment	5,584	4,572
Related Allowance	379	1,377
Average Recorded Investment	8,653	2,711
Real Estate | Commercial - Investor Owned
Financing Receivable, Impaired [Line Items]
Unpaid Contractual Principal Balance	14,053	15,676
Recorded Investment With No Allowance	1,865	914
Recorded Investment With Allowance	7,782	10,213
Total Recorded Investment	9,647	11,127
Related Allowance	2,199	2,315
Average Recorded Investment	9,793	10,562
Real Estate | Construction and Land Development
Financing Receivable, Impaired [Line Items]
Unpaid Contractual Principal Balance	13,192	19,685
Recorded Investment With No Allowance	748	1,628
Recorded Investment With Allowance	9,347	13,139
Total Recorded Investment	10,095	14,767
Related Allowance	2,538	2,927
Average Recorded Investment	11,295	16,114
Real Estate | Residential
Financing Receivable, Impaired [Line Items]
Unpaid Contractual Principal Balance	4,164	6,465
Recorded Investment With No Allowance	1,705	2,211
Recorded Investment With Allowance	2,178	3,311
Total Recorded Investment	3,883	5,522
Related Allowance	506	896
Average Recorded Investment	4,800	9,588
Consumer & Other
Financing Receivable, Impaired [Line Items]
Unpaid Contractual Principal Balance	0	0
Recorded Investment With No Allowance	0	0
Recorded Investment With Allowance	0	0
Total Recorded Investment	0	0
Related Allowance	0	0
Average Recorded Investment	$ 0	$ 0