Loans Held for Investment (LHFI) and Allowance for Loan Losses, excluding Covered Loans Part 5 (Details) (USD $)	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Financing Receivable, Recorded Investment, Aging [Abstract]
Past Due 30 - 89 Days	$ 34,265,000		$ 40,881,000
Past Due Greater Than 90 Days	4,230,000	[1]	3,608,000	[1]
Total Past Due	38,495,000		44,489,000
Nonaccrual	110,458,000		142,923,000
Current Loans	5,708,531,000		5,872,830,000
Total LHFI, Excluding Covered Loans	5,857,484,000		6,060,242,000
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	43,600,000		19,400,000
Covered Serviced Financing Receivable Available for Repurchase, Recorded Investment, Equal to Greater than 90 Days Past Due	39,400,000		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
Number of Loan Types For Commercial Portfolio	13		13		13
Number of Risk Rate Factors For Commercial Loans	360		360		130
Number of Unique Qualitative Factors Used To Analyze Commercial Loans	8		8
The Minimum Score For Qualitative Risk Factor	0		0
The Maximum Score For Qualitative Risk Factor	100		100
Construction, Land Development And Other Financing Receivable [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total LHFI, Excluding Covered Loans	474,082,000		583,316,000
Residential Financing Receivable [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total LHFI, Excluding Covered Loans	1,760,930,000		1,732,056,000
Nonresidential Properties Financing Receivables [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total LHFI, Excluding Covered Loans	1,425,774,000		1,498,108,000
Other Real Estate Secured Financing Receivable [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Total LHFI, Excluding Covered Loans	204,849,000		231,963,000
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	1,784,000		1,651,000
Past Due Greater Than 90 Days	1,657,000	[1]	0	[1]
Total Past Due	3,441,000		1,651,000
Nonaccrual	40,413,000		57,831,000
Current Loans	430,228,000		523,834,000
Total LHFI, Excluding Covered Loans	474,082,000		583,316,000
Real Estate Secured Financing Receivable [Member] | Residential Financing Receivable [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Past Due 30 - 89 Days	9,755,000		11,654,000
Past Due Greater Than 90 Days	1,306,000	[1]	1,278,000	[1]
Total Past Due	11,061,000		12,932,000
Nonaccrual	24,348,000		30,313,000
Current Loans	1,725,521,000		1,688,811,000
Total LHFI, Excluding Covered Loans	1,760,930,000		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	9,925,000		9,149,000
Past Due Greater Than 90 Days	0	[1]	31,000	[1]
Total Past Due	9,925,000		9,180,000
Nonaccrual	23,981,000		29,013,000
Current Loans	1,391,868,000		1,459,915,000
Total LHFI, Excluding Covered Loans	1,425,774,000		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	879,000		441,000
Past Due Greater Than 90 Days	0	[1]	0	[1]
Total Past Due	879,000		441,000
Nonaccrual	5,871,000		6,154,000
Current Loans	198,099,000		225,368,000
Total LHFI, Excluding Covered Loans	204,849,000		231,963,000
Commercial And Industrial Loans [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Past Due 30 - 89 Days	1,646,000		4,178,000
Past Due Greater Than 90 Days	769,000	[1]	39,000	[1]
Total Past Due	2,415,000		4,217,000
Nonaccrual	14,148,000		16,107,000
Current Loans	1,122,802,000		1,048,045,000
Total LHFI, Excluding Covered Loans	1,139,365,000		1,068,369,000
Consumer Loans Financing Receivable [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Past Due 30 - 89 Days	7,172,000		13,741,000
Past Due Greater Than 90 Days	498,000	[1]	2,260,000	[1]
Total Past Due	7,670,000		16,001,000
Nonaccrual	825,000		2,112,000
Current Loans	235,261,000		384,052,000
Total LHFI, Excluding Covered Loans	243,756,000		402,165,000
Other Loans Financing Receivable [Member]
Financing Receivable, Recorded Investment, Aging [Abstract]
Past Due 30 - 89 Days	3,104,000		67,000
Past Due Greater Than 90 Days	0	[1]	0	[1]
Total Past Due	3,104,000		67,000
Nonaccrual	872,000		1,393,000
Current Loans	604,752,000		542,805,000
Total LHFI, Excluding Covered Loans	$ 608,728,000		$ 544,265,000

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