Loans Held for Investment (LHFI) and Allowance for Loan Losses, excluding Covered Loans Part 1 (Details) (USD $) In Thousands	Jun. 30, 2011	Dec. 31, 2010	Jun. 30, 2010	Dec. 31, 2009
Loan Portfolio [Abstract]
Loans Held For Investment, Excluding Covered Loans	$ 5,906,316	$ 6,060,242
Less Allowance For Loan Losses	86,846	93,510	100,656	103,662
Net Loans Held For Investment, Excluding Covered Loans	5,819,470	5,966,732
Loans and Leases Receivable, Other Information [Abstract]
Loans Held For Investment, Individually Evaluated For Impairment	121,018	142,923
Loans Held For Investment, Collectively Evaluated For Impairment	5,785,298	5,917,319
Total	5,906,316	6,060,242
Real Estate Secured Financing Receivable [Member] | Construction Land Development And Other Financing Receivable [Member]
Loan Portfolio [Abstract]
Loans Held For Investment, Excluding Covered Loans	510,867	583,316
Less Allowance For Loan Losses	31,201	35,562	40,311	43,552
Loans and Leases Receivable, Other Information [Abstract]
Loans Held For Investment, Individually Evaluated For Impairment	46,057	57,831
Loans Held For Investment, Collectively Evaluated For Impairment	464,810	525,485
Total	510,867	583,316
Real Estate Secured Financing Receivable [Member] | Residential Financing Receivable [Member]
Loan Portfolio [Abstract]
Loans Held For Investment, Excluding Covered Loans	1,737,744	1,732,056
Less Allowance For Loan Losses	11,842	13,051	12,632	13,151
Loans and Leases Receivable, Other Information [Abstract]
Loans Held For Investment, Individually Evaluated For Impairment	23,604	30,313
Loans Held For Investment, Collectively Evaluated For Impairment	1,714,140	1,701,743
Total	1,737,744	1,732,056
Real Estate Secured Financing Receivable [Member] | Nonresidential Properties Financing Receivables [Member]
Loan Portfolio [Abstract]
Loans Held For Investment, Excluding Covered Loans	1,457,328	1,498,108
Less Allowance For Loan Losses	20,893	20,980	22,220	20,110
Loans and Leases Receivable, Other Information [Abstract]
Loans Held For Investment, Individually Evaluated For Impairment	29,055	29,013
Loans Held For Investment, Collectively Evaluated For Impairment	1,428,273	1,469,095
Total	1,457,328	1,498,108
Real Estate Secured Financing Receivable [Member] | Other Real Estate Secured Financing Receivable [Member]
Loan Portfolio [Abstract]
Loans Held For Investment, Excluding Covered Loans	208,797	231,963
Less Allowance For Loan Losses	1,780	1,582	1,638	1,631
Loans and Leases Receivable, Other Information [Abstract]
Loans Held For Investment, Individually Evaluated For Impairment	5,120	6,154
Loans Held For Investment, Collectively Evaluated For Impairment	203,677	225,809
Total	208,797	231,963
Commercial And Industrial Loans Financing Receivable [Member]
Loan Portfolio [Abstract]
Loans Held For Investment, Excluding Covered Loans	1,082,127	1,068,369
Loans and Leases Receivable, Other Information [Abstract]
Loans Held For Investment, Individually Evaluated For Impairment	15,180	16,107
Loans Held For Investment, Collectively Evaluated For Impairment	1,066,947	1,052,262
Total	1,082,127	1,068,369
Consumer Loans Financing Receivable [Member]
Loan Portfolio [Abstract]
Loans Held For Investment, Excluding Covered Loans	332,032	402,165
Less Allowance For Loan Losses	4,377	5,400	6,308	7,246
Loans and Leases Receivable, Other Information [Abstract]
Loans Held For Investment, Individually Evaluated For Impairment	997	2,112
Loans Held For Investment, Collectively Evaluated For Impairment	331,035	400,053
Total	332,032	402,165
Other Loans Financing Receivable [Member]
Loan Portfolio [Abstract]
Loans Held For Investment, Excluding Covered Loans	577,421	544,265
Less Allowance For Loan Losses	2,621	2,160	2,104	1,697
Loans and Leases Receivable, Other Information [Abstract]
Loans Held For Investment, Individually Evaluated For Impairment	1,005	1,393
Loans Held For Investment, Collectively Evaluated For Impairment	576,416	542,872
Total	577,421	544,265
Construction Land Development And Other Financing Receivable [Member]
Loan Portfolio [Abstract]
Loans Held For Investment, Excluding Covered Loans	510,867	583,316
Loans and Leases Receivable, Other Information [Abstract]
Total	510,867	583,316
Residential Financing Receivable [Member]
Loan Portfolio [Abstract]
Loans Held For Investment, Excluding Covered Loans	1,737,744	1,732,056
Loans and Leases Receivable, Other Information [Abstract]
Total	1,737,744	1,732,056
Nonresidential Properties Financing Receivables [Member]
Loan Portfolio [Abstract]
Loans Held For Investment, Excluding Covered Loans	1,457,328	1,498,108
Loans and Leases Receivable, Other Information [Abstract]
Total	1,457,328	1,498,108
Other Real Estate Secured Financing Receivable [Member]
Loan Portfolio [Abstract]
Loans Held For Investment, Excluding Covered Loans	208,797	231,963
Loans and Leases Receivable, Other Information [Abstract]
Total	$ 208,797	$ 231,963