NON COVERED LOANS AND ALLOWANCE FOR LOAN LOSSES (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Non-Covered loans receivable disclosures
Loans receivable, excluding covered loans, gross	$ 10,288,426,000	$ 8,717,388,000
Unearned fees, premiums and discounts, net	(16,762,000)	(56,781,000)
Allowance for non-covered loans receivable	(209,876,000)	(230,408,000)
Non-covered loans receivable, excluding covered loans, net	10,061,788,000	8,430,199,000
Accrued interest on covered and non-covered loans receivable	68,500,000	65,600,000
Covered and non-covered loans receivable pledged to secure borrowings from the FHLB and the Federal Reserve Bank	8,650,000,000	8,140,000,000
Residential
Non-Covered loans receivable disclosures
Loans receivable, excluding covered loans, gross	2,729,803,000	2,093,769,000
Acquired mortgage loans with variable payment option features	14,000,000	16,900,000
Ratio of mortgage loans with variable payment option features to total mortgage loans within same portfolio category (as a percent)	1.00%	1.00%
Residential | Minimum
Non-Covered loans receivable disclosures
Number of units of residential property securing fixed and adjustable rate first mortgage loans	1
Residential | Maximum
Non-Covered loans receivable disclosures
Number of units of residential property securing fixed and adjustable rate first mortgage loans	4
Residential | Single-family
Non-Covered loans receivable disclosures
Loans receivable, excluding covered loans, gross	1,796,635,000	1,119,024,000
New first mortgage loans originated	924,300,000	430,800,000
Mortgage loans with interest-only features	5,600,000	7,800,000
Ratio of mortgage loans with interest-only features to total mortgage loans within same portfolio category (as a percent)	1.00%	1.00%
Residential | Multifamily
Non-Covered loans receivable disclosures
Loans receivable, excluding covered loans, gross	933,168,000	974,745,000
New first mortgage loans originated	47,600,000	26,400,000
Residential | Multifamily | Minimum
Non-Covered loans receivable disclosures
Adjustable rate mortgage, term of initial fixed interest rates	6 months
Residential | Multifamily | Midrange
Non-Covered loans receivable disclosures
Adjustable rate mortgage, term of initial fixed interest rates	3 years
Residential | Multifamily | Maximum
Non-Covered loans receivable disclosures
Adjustable rate mortgage, term of initial fixed interest rates	5 years
Commercial Real Estate ("CRE")
Non-Covered loans receivable disclosures
Loans receivable, excluding covered loans, gross	3,832,365,000	3,906,738,000
Commercial Real Estate ("CRE") | Income producing
Non-Covered loans receivable disclosures
Loans receivable, excluding covered loans, gross	3,487,866,000	3,392,984,000
Commercial Real Estate ("CRE") | Construction
Non-Covered loans receivable disclosures
Loans receivable, excluding covered loans, gross	171,410,000	278,047,000
Commercial Real Estate ("CRE") | Land
Non-Covered loans receivable disclosures
Loans receivable, excluding covered loans, gross	173,089,000	235,707,000
Commercial and Industrial ("C&I")
Non-Covered loans receivable disclosures
Loans receivable, excluding covered loans, gross	3,142,472,000	1,983,355,000
Commercial and Industrial ("C&I") | Commercial Business
Non-Covered loans receivable disclosures
Loans receivable, excluding covered loans, gross	2,655,917,000	1,674,698,000
Commercial and Industrial ("C&I") | Trade finance
Non-Covered loans receivable disclosures
Loans receivable, excluding covered loans, gross	486,555,000	308,657,000
Consumer
Non-Covered loans receivable disclosures
Loans receivable, excluding covered loans, gross	583,786,000	733,526,000
Consumer | Student loans
Non-Covered loans receivable disclosures
Loans receivable, excluding covered loans, gross	306,325,000	490,314,000
Consumer | Other Consumer
Non-Covered loans receivable disclosures
Loans receivable, excluding covered loans, gross	$ 277,461,000	$ 243,212,000