Loans Held for Investment (LHFI) and Allowance for Loan Losses, excluding Covered Loans Part 4 (Details) (USD $)	9 Months Ended		12 Months Ended
	Sep. 30, 2011		Dec. 31, 2010
Financing Receivable, Recorded Investment, Aging [Abstract]
Past Due 30 - 89 Days	$ 53,916,000		$ 40,881,000
Past Due Greater Than 90 Days	3,166,000	[1]	3,608,000	[1]
Total Past Due	57,082,000		44,489,000
Nonaccrual	99,578,000		142,923,000
Current Loans	5,627,052,000		5,872,830,000
Total LHFI, Excluding Covered Loans	5,783,712,000		6,060,242,000
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	36,100,000		19,400,000
Covered Serviced Financing Receivable Available for Repurchase, Recorded Investment, Equal to Greater than 90 Days Past Due	33,000,000		15,800,000
Percentage of Outstanding Principal To Be Repurchased Under GNMA Optional Repurchase Program (in hundredths)	100.00%
Payment to Acquire securities Sold Under Optional Repurchase Program			53,900,000
Real Estate Secured Financing Receivable [Member] | Construction Land Development And Other Financing Receivable [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Past Due 30 - 89 Days	4,653,000		1,651,000
Past Due Greater Than 90 Days	844,000	[1]
Total Past Due	5,497,000		1,651,000
Nonaccrual	29,594,000		57,831,000
Current Loans	446,730,000		523,834,000
Total LHFI, Excluding Covered Loans	481,821,000		583,316,000
Real Estate Secured Financing Receivable [Member] | Residential Financing Receivable [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Past Due 30 - 89 Days	12,798,000		11,654,000
Past Due Greater Than 90 Days	1,743,000	[1]	1,278,000	[1]
Total Past Due	14,541,000		12,932,000
Nonaccrual	23,558,000		30,313,000
Current Loans	1,679,267,000		1,688,811,000
Total LHFI, Excluding Covered Loans	1,717,366,000		1,732,056,000
Real Estate Secured Financing Receivable [Member] | Nonresidential Properties Financing Receivables [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Past Due 30 - 89 Days	19,863,000		9,149,000
Past Due Greater Than 90 Days	0	[1]	31,000	[1]
Total Past Due	19,863,000		9,180,000
Nonaccrual	25,303,000		29,013,000
Current Loans	1,392,407,000		1,459,811,000
Total LHFI, Excluding Covered Loans	1,437,573,000		1,498,108,000
Real Estate Secured Financing Receivable [Member] | Other Real Estate Secured Financing Receivable [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Past Due 30 - 89 Days	63,000		441,000
Total Past Due	63,000		441,000
Nonaccrual	4,821,000		6,154,000
Current Loans	203,100,000		225,368,000
Total LHFI, Excluding Covered Loans	207,984,000		231,963,000
Commercial And Industrial Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Past Due 30 - 89 Days	8,781,000		4,178,000
Past Due Greater Than 90 Days	0	[1]	39,000	[1]
Total Past Due	8,781,000		4,217,000
Nonaccrual	14,204,000		16,107,000
Current Loans	1,060,768,000		1,048,045,000
Total LHFI, Excluding Covered Loans	1,083,753,000		1,068,369,000
Consumer Loans Financing Receivable [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Past Due 30 - 89 Days	6,973,000		13,741,000
Past Due Greater Than 90 Days	579,000	[1]	2,260,000	[1]
Total Past Due	7,552,000		16,001,000
Nonaccrual	907,000		2,112,000
Current Loans	259,543,000		384,052,000
Total LHFI, Excluding Covered Loans	268,002,000		402,165,000
Other Loans Financing Receivable [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Past Due 30 - 89 Days	785,000		67,000
Total Past Due	785,000		67,000
Nonaccrual	1,191,000		1,393,000
Current Loans	585,237,000		542,805,000
Total LHFI, Excluding Covered Loans	587,213,000		544,265,000
Construction Land Development And Other Financing Receivable [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total LHFI, Excluding Covered Loans	481,821,000		583,316,000
Residential Financing Receivable [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total LHFI, Excluding Covered Loans	1,717,366,000		1,732,056,000
Nonresidential Properties Financing Receivables [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total LHFI, Excluding Covered Loans	1,437,573,000		1,498,108,000
Other Real Estate Secured Financing Receivable [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total LHFI, Excluding Covered Loans	$ 207,984,000		$ 231,963,000

[1] Past due greater than 90 days but still accruing interest.