COVERED ASSETS AND FDIC INDEMNIFICATION ASSET (Details 2) (USD $)	Dec. 31, 2011	Dec. 31, 2010
Credit Quality Indicators
Additional advances under shared-loss agreements	$ 583,800,000
Total allowance allocated to additional advances	6,600,000
Percentage of allowance allocated to additional advances	3.10%
Carrying Amounts And Composition Of Covered Loans
Total principal balance	4,718,084,000	5,955,773,000
Covered discount	(788,295,000)	(1,150,672,000)
Net valuation of loans	3,929,789,000	4,805,101,000
Allowance on covered loans	(6,647,000)	(4,225,000)
Total covered loans, net	3,923,142,000	4,800,876,000
Pass/Watch
Carrying Amounts And Composition Of Covered Loans
Total principal balance	3,439,848,000	4,323,086,000
Special Mention
Carrying Amounts And Composition Of Covered Loans
Total principal balance	146,585,000	297,863,000
Substandard
Carrying Amounts And Composition Of Covered Loans
Total principal balance	1,112,568,000	1,277,504,000
Doubtful
Carrying Amounts And Composition Of Covered Loans
Total principal balance	19,083,000	57,320,000
Real Estate Loans
Carrying Amounts And Composition Of Covered Loans
Total principal balance	3,788,478,000	4,776,263,000
Real Estate Loans | Pass/Watch
Carrying Amounts And Composition Of Covered Loans
Total principal balance	2,700,389,000	3,382,602,000
Real Estate Loans | Special Mention
Carrying Amounts And Composition Of Covered Loans
Total principal balance	111,878,000	232,825,000
Real Estate Loans | Substandard
Carrying Amounts And Composition Of Covered Loans
Total principal balance	961,813,000	1,115,181,000
Real Estate Loans | Doubtful
Carrying Amounts And Composition Of Covered Loans
Total principal balance	14,398,000	45,655,000
Real Estate Loans | Residential Single-family
Carrying Amounts And Composition Of Covered Loans
Total principal balance	442,732,000	553,541,000
Real Estate Loans | Residential Single-family | Pass/Watch
Carrying Amounts And Composition Of Covered Loans
Total principal balance	427,918,000	525,979,000
Real Estate Loans | Residential Single-family | Special Mention
Carrying Amounts And Composition Of Covered Loans
Total principal balance	1,085,000	2,153,000
Real Estate Loans | Residential Single-family | Substandard
Carrying Amounts And Composition Of Covered Loans
Total principal balance	13,729,000	25,157,000
Real Estate Loans | Residential Single-family | Doubtful
Carrying Amounts And Composition Of Covered Loans
Total principal balance		252,000
Real Estate Loans | Residential Multifamily
Carrying Amounts And Composition Of Covered Loans
Total principal balance	918,941,000	1,093,331,000
Real Estate Loans | Residential Multifamily | Pass/Watch
Carrying Amounts And Composition Of Covered Loans
Total principal balance	779,694,000	1,008,274,000
Real Estate Loans | Residential Multifamily | Special Mention
Carrying Amounts And Composition Of Covered Loans
Total principal balance	26,124,000	15,114,000
Real Estate Loans | Residential Multifamily | Substandard
Carrying Amounts And Composition Of Covered Loans
Total principal balance	113,123,000	67,366,000
Real Estate Loans | Residential Multifamily | Doubtful
Carrying Amounts And Composition Of Covered Loans
Total principal balance		2,577,000
Real Estate Loans | Commercial and Industrial Real Estate
Carrying Amounts And Composition Of Covered Loans
Total principal balance	1,773,760,000	2,085,674,000
Real Estate Loans | Commercial and Industrial Real Estate | Pass/Watch
Carrying Amounts And Composition Of Covered Loans
Total principal balance	1,249,781,000	1,520,135,000
Real Estate Loans | Commercial and Industrial Real Estate | Special Mention
Carrying Amounts And Composition Of Covered Loans
Total principal balance	43,810,000	89,870,000
Real Estate Loans | Commercial and Industrial Real Estate | Substandard
Carrying Amounts And Composition Of Covered Loans
Total principal balance	472,003,000	466,588,000
Real Estate Loans | Commercial and Industrial Real Estate | Doubtful
Carrying Amounts And Composition Of Covered Loans
Total principal balance	8,166,000	9,081,000
Real Estate Loans | Construction and Land
Carrying Amounts And Composition Of Covered Loans
Total principal balance	653,045,000	1,043,717,000
Real Estate Loans | Construction and Land | Pass/Watch
Carrying Amounts And Composition Of Covered Loans
Total principal balance	242,996,000	328,214,000
Real Estate Loans | Construction and Land | Special Mention
Carrying Amounts And Composition Of Covered Loans
Total principal balance	40,859,000	125,688,000
Real Estate Loans | Construction and Land | Substandard
Carrying Amounts And Composition Of Covered Loans
Total principal balance	362,958,000	556,070,000
Real Estate Loans | Construction and Land | Doubtful
Carrying Amounts And Composition Of Covered Loans
Total principal balance	6,232,000	33,745,000
Other Loans
Carrying Amounts And Composition Of Covered Loans
Total principal balance	929,606,000	1,179,510,000
Other Loans | Pass/Watch
Carrying Amounts And Composition Of Covered Loans
Total principal balance	739,459,000	940,484,000
Other Loans | Special Mention
Carrying Amounts And Composition Of Covered Loans
Total principal balance	34,707,000	65,038,000
Other Loans | Substandard
Carrying Amounts And Composition Of Covered Loans
Total principal balance	150,755,000	162,323,000
Other Loans | Doubtful
Carrying Amounts And Composition Of Covered Loans
Total principal balance	4,685,000	11,665,000
Other Loans | Commercial Business
Carrying Amounts And Composition Of Covered Loans
Total principal balance	831,762,000	1,072,020,000
Other Loans | Commercial Business | Pass/Watch
Carrying Amounts And Composition Of Covered Loans
Total principal balance	643,117,000	834,252,000
Other Loans | Commercial Business | Special Mention
Carrying Amounts And Composition Of Covered Loans
Total principal balance	34,707,000	64,702,000
Other Loans | Commercial Business | Substandard
Carrying Amounts And Composition Of Covered Loans
Total principal balance	149,253,000	161,401,000
Other Loans | Commercial Business | Doubtful
Carrying Amounts And Composition Of Covered Loans
Total principal balance	4,685,000	11,665,000
Other Loans | Other Consumer
Carrying Amounts And Composition Of Covered Loans
Total principal balance	97,844,000	107,490,000
Other Loans | Other Consumer | Pass/Watch
Carrying Amounts And Composition Of Covered Loans
Total principal balance	96,342,000	106,232,000
Other Loans | Other Consumer | Special Mention
Carrying Amounts And Composition Of Covered Loans
Total principal balance		336,000
Other Loans | Other Consumer | Substandard
Carrying Amounts And Composition Of Covered Loans
Total principal balance	1,502,000	922,000
Residential
Credit Quality Indicators
Additional advances under shared-loss agreements	12,700,000
Total allowance allocated to additional advances	70,000
Commercial Real Estate ("CRE")
Credit Quality Indicators
Additional advances under shared-loss agreements	149,100,000
Total allowance allocated to additional advances	4,000,000
Commercial and Industrial ("C&I")
Credit Quality Indicators
Additional advances under shared-loss agreements	390,300,000
Total allowance allocated to additional advances	2,400,000
Consumer
Credit Quality Indicators
Additional advances under shared-loss agreements	31,600,000
Total allowance allocated to additional advances	$ 174,000