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, 2013	Dec. 31, 2012
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	$ 7,291	$ 2,783
90 or More Days Past Due	21,132	26,175
Total Past Due	28,423	28,958
Current	130,389	172,160
Total	158,812	201,118
Commercial & Industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	1,642	319
90 or More Days Past Due	1,166	3,925
Total Past Due	2,808	4,244
Current	6,287	17,790
Total	9,095	22,034
Consumer & Other
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	0	1
90 or More Days Past Due	0	2
Total Past Due	0	3
Current	1,845	1,271
Total	1,845	1,274
Commercial Real Estate Owner Occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	3,323	887
90 or More Days Past Due	5,024	5,144
Total Past Due	8,347	6,031
Current	34,905	41,109
Total	43,252	47,140
Commercial Real Estate Investor Owned
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	1,653	308
90 or More Days Past Due	4,465	665
Total Past Due	6,118	973
Current	45,724	56,629
Total	51,842	57,602
Construction and Land Development
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	0	36
90 or More Days Past Due	3,886	13,532
Total Past Due	3,886	13,568
Current	11,446	16,969
Total	15,332	30,537
Residential Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	673	1,232
90 or More Days Past Due	6,591	2,907
Total Past Due	7,264	4,139
Current	30,182	38,392
Total	$ 37,446	$ 42,531