Loans Held for Investment (LHFI) and Allowance for Loan Losses, excluding Covered Loans Part 1 (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011	Mar. 31, 2011	Dec. 31, 2010
Loan Portfolio [Abstract]
Loans held for investment (LHFI)	$ 5,774,753	$ 5,857,484
Less Allowance For Loan Losses	90,879	89,518	93,398	93,510
Net Loans Held For Investment, Excluding Covered Loans	5,683,874	5,767,966
Loans and Leases Receivable, Other Information [Abstract]
Loans Held For Investment, Individually Evaluated For Impairment	105,773	110,458
Loans Held For Investment, Collectively Evaluated For Impairment	5,668,980	5,747,026
Total	5,774,753	5,857,484
Construction Land Development And Other Financing Receivable [Member]
Loan Portfolio [Abstract]
Loans held for investment (LHFI)	465,486	474,082
Loans and Leases Receivable, Other Information [Abstract]
Total	465,486	474,082
Residential Financing Receivable [Member]
Loan Portfolio [Abstract]
Loans held for investment (LHFI)	1,722,357	1,760,930
Loans and Leases Receivable, Other Information [Abstract]
Total	1,722,357	1,760,930
Nonresidential Properties Financing Receivables [Member]
Loan Portfolio [Abstract]
Loans held for investment (LHFI)	1,419,902	1,425,774
Loans and Leases Receivable, Other Information [Abstract]
Total	1,419,902	1,425,774
Other Real Estate Secured Financing Receivable [Member]
Loan Portfolio [Abstract]
Loans held for investment (LHFI)	199,400	204,849
Loans and Leases Receivable, Other Information [Abstract]
Total	199,400	204,849
Real Estate Secured Financing Receivable [Member] | Construction Land Development And Other Financing Receivable [Member]
Loan Portfolio [Abstract]
Loans held for investment (LHFI)	465,486	474,082
Less Allowance For Loan Losses	25,715	27,220	36,504	35,562
Loans and Leases Receivable, Other Information [Abstract]
Loans Held For Investment, Individually Evaluated For Impairment	38,023	40,413
Loans Held For Investment, Collectively Evaluated For Impairment	427,463	433,669
Total	465,486	474,082
Real Estate Secured Financing Receivable [Member] | Residential Financing Receivable [Member]
Loan Portfolio [Abstract]
Loans held for investment (LHFI)	1,722,357	1,760,930
Less Allowance For Loan Losses	12,740	12,650	11,993	13,051
Loans and Leases Receivable, Other Information [Abstract]
Loans Held For Investment, Individually Evaluated For Impairment	24,446	24,348
Loans Held For Investment, Collectively Evaluated For Impairment	1,697,911	1,736,506
Total	1,722,357	1,760,930
Real Estate Secured Financing Receivable [Member] | Nonresidential Properties Financing Receivables [Member]
Loan Portfolio [Abstract]
Loans held for investment (LHFI)	1,419,902	1,425,774
Less Allowance For Loan Losses	27,884	24,358	21,210	20,980
Loans and Leases Receivable, Other Information [Abstract]
Loans Held For Investment, Individually Evaluated For Impairment	33,034	23,981
Loans Held For Investment, Collectively Evaluated For Impairment	1,386,868	1,401,793
Total	1,419,902	1,425,774
Real Estate Secured Financing Receivable [Member] | Other Real Estate Secured Financing Receivable [Member]
Loan Portfolio [Abstract]
Loans held for investment (LHFI)	199,400	204,849
Less Allowance For Loan Losses	3,021	3,079	1,470	1,582
Loans and Leases Receivable, Other Information [Abstract]
Loans Held For Investment, Individually Evaluated For Impairment	4,557	5,871
Loans Held For Investment, Collectively Evaluated For Impairment	194,843	198,978
Total	199,400	204,849
Commercial And Industrial Loans [Member]
Loan Portfolio [Abstract]
Loans held for investment (LHFI)	1,142,813	1,139,365
Less Allowance For Loan Losses	16,038	15,868	15,091	14,775
Loans and Leases Receivable, Other Information [Abstract]
Loans Held For Investment, Individually Evaluated For Impairment	4,929	14,148
Loans Held For Investment, Collectively Evaluated For Impairment	1,137,884	1,125,217
Total	1,142,813	1,139,365
Consumer Loans Financing Receivable [Member]
Loan Portfolio [Abstract]
Loans held for investment (LHFI)	210,713	243,756
Less Allowance For Loan Losses	3,204	3,656	4,834	5,400
Loans and Leases Receivable, Other Information [Abstract]
Loans Held For Investment, Individually Evaluated For Impairment	536	825
Loans Held For Investment, Collectively Evaluated For Impairment	210,177	242,931
Total	210,713	243,756
Other Loans Financing Receivable [Member]
Loan Portfolio [Abstract]
Loans held for investment (LHFI)	614,082	608,728
Less Allowance For Loan Losses	2,277	2,687	2,296	2,160
Loans and Leases Receivable, Other Information [Abstract]
Loans Held For Investment, Individually Evaluated For Impairment	248	872
Loans Held For Investment, Collectively Evaluated For Impairment	613,834	607,856
Total	$ 614,082	$ 608,728