Loans Held for Investment (LHFI) and Allowance for Loan Losses, LHFI (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Loan Portfolio [Abstract]
Loans held for investment (LHFI)	$ 5,527,963	$ 5,857,484
Less Allowance For Loan Losses, LHFI	83,526	89,518
Net LHFI	5,444,437	5,767,966
Loans and Leases Receivable, Other Information [Abstract]
LHFI, Individually Evaluated For Impairment	80,658	110,458
LHFI, Collectively Evaluated For Impairment	5,447,305	5,747,026
Total LHFI	5,527,963	5,857,484
Real Estate Secured Financing Receivable [Member] \| Construction Land Development And Other Land Loans [Member]
Loan Portfolio [Abstract]
Loans held for investment (LHFI)	460,599	474,082
Loans and Leases Receivable, Other Information [Abstract]
LHFI, Individually Evaluated For Impairment	26,077	40,413
LHFI, Collectively Evaluated For Impairment	434,522	433,669
Total LHFI	460,599	474,082
Real Estate Secured Financing Receivable [Member] \| Secured by 1-4 Family Residential Properties[Member]
Loan Portfolio [Abstract]
Loans held for investment (LHFI)	1,511,514	1,760,930
Loans and Leases Receivable, Other Information [Abstract]
LHFI, Individually Evaluated For Impairment	24,260	24,348
LHFI, Collectively Evaluated For Impairment	1,487,254	1,736,582
Total LHFI	1,511,514	1,760,930
Real Estate Secured Financing Receivable [Member] \| Secured by NonFarm, Nonresidential Properties [Member]
Loan Portfolio [Abstract]
Loans held for investment (LHFI)	1,397,536	1,425,774
Loans and Leases Receivable, Other Information [Abstract]
LHFI, Individually Evaluated For Impairment	18,873	23,981
LHFI, Collectively Evaluated For Impairment	1,378,663	1,401,793
Total LHFI	1,397,536	1,425,774
Real Estate Secured Financing Receivable [Member] \| Other Real Estate Properties [Member]
Loan Portfolio [Abstract]
Loans held for investment (LHFI)	184,804	204,849
Loans and Leases Receivable, Other Information [Abstract]
LHFI, Individually Evaluated For Impairment	3,900	5,871
LHFI, Collectively Evaluated For Impairment	180,904	198,978
Total LHFI	184,804	204,849
Commercial And Industrial Loans [Member]
Loan Portfolio [Abstract]
Loans held for investment (LHFI)	1,163,681	1,139,365
Loans and Leases Receivable, Other Information [Abstract]
LHFI, Individually Evaluated For Impairment	6,215	14,148
LHFI, Collectively Evaluated For Impairment	1,157,466	1,125,217
Total LHFI	1,163,681	1,139,365
Consumer Loans [Member]
Loan Portfolio [Abstract]
Loans held for investment (LHFI)	181,896	243,756
Loans and Leases Receivable, Other Information [Abstract]
LHFI, Individually Evaluated For Impairment	411	825
LHFI, Collectively Evaluated For Impairment	181,485	242,931
Total LHFI	181,896	243,756
Other Loans [Member]
Loan Portfolio [Abstract]
Loans held for investment (LHFI)	627,933	608,728
Loans and Leases Receivable, Other Information [Abstract]
LHFI, Individually Evaluated For Impairment	922	872
LHFI, Collectively Evaluated For Impairment	627,011	607,856
Total LHFI	$ 627,933	$ 608,728

The allowance for loan and lease losses represents the reserve to cover probable credit losses related to specifically identified loans and leases, as well as probable credit losses inherent in the remainder of the loan portfolio as of the balance sheet date. For banks, include currently required allocated transfer risk reserves. Include carryover of or adjustments to the allowance for loan losses in connection with business combinations determined to be appropriate.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher OTS

-Name Federal Regulation (FR)

-Number Title 12

-Chapter V

-Section 563c.102

-Paragraph 8

-Subparagraph a(ii)

-Subsection I

-LegacyDoc This is a non-GAAP reference that was included in the 2009 taxonomy. It will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 6

-Section L

-Subsection 1

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 114

-Paragraph 20

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.7(d))

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Article 9

-Section 03

-Paragraph 7

-Subparagraph d

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 5

-Paragraph 8, 9

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (b)(1)(ii)

-URI http://asc.fasb.org/extlink&oid=6379141&loc=d3e15032-111544

+ Details

- Definition

Reflects the aggregate gross carrying amount of all categories of loans and leases held in portfolio, after deducting deferred income, but before deducting the allowance for losses on loans and leases.

+ References+ Details