NON-COVERED LOANS AND ALLOWANCE FOR LOAN LOSSES (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Non-Covered loans receivable disclosures
Loans receivable, excluding covered loans, gross	$ 14,599,188	$ 11,958,873
Unearned fees, premiums and discounts, net	(26,165)	(19,301)
Allowance for non-covered loans receivable	(234,236)	(229,382)
Non-covered loans receivable, excluding covered loans, net	14,338,787	11,710,190
Residential
Non-Covered loans receivable disclosures
Loans receivable, excluding covered loans, gross	3,977,770	3,088,031
Residential | Single-family
Non-Covered loans receivable disclosures
Loans receivable, excluding covered loans, gross	3,000,923	2,187,323
Residential | Multifamily
Non-Covered loans receivable disclosures
Loans receivable, excluding covered loans, gross	976,847	900,708
Commercial Real Estate ("CRE")
Non-Covered loans receivable disclosures
Loans receivable, excluding covered loans, gross	4,362,612	3,894,695
Commercial Real Estate ("CRE") | Income producing
Non-Covered loans receivable disclosures
Loans receivable, excluding covered loans, gross	4,128,494	3,644,035
Commercial Real Estate ("CRE") | Construction
Non-Covered loans receivable disclosures
Loans receivable, excluding covered loans, gross	121,597	121,589
Commercial Real Estate ("CRE") | Land
Non-Covered loans receivable disclosures
Loans receivable, excluding covered loans, gross	112,521	129,071
Commercial and Industrial ("C&I")
Non-Covered loans receivable disclosures
Loans receivable, excluding covered loans, gross	4,881,368	4,231,265
Commercial and Industrial ("C&I") | Commercial Business
Non-Covered loans receivable disclosures
Loans receivable, excluding covered loans, gross	4,199,686	3,569,388
Commercial and Industrial ("C&I") | Trade finance
Non-Covered loans receivable disclosures
Loans receivable, excluding covered loans, gross	681,682	661,877
Consumer
Non-Covered loans receivable disclosures
Loans receivable, excluding covered loans, gross	1,377,438	744,882
Consumer | Student loans
Non-Covered loans receivable disclosures
Loans receivable, excluding covered loans, gross	702,291	475,799
Consumer | Other Consumer
Non-Covered loans receivable disclosures
Loans receivable, excluding covered loans, gross	$ 675,147	$ 269,083