NON-COVERED LOANS AND ALLOWANCE FOR LOAN LOSSES (Details 3) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Credit Risk and Concentrations
Percentage of non-covered commercial real estate loans and non-covered residential loans secured by real properties located in California	86.00%
Loans receivable, excluding covered loans, gross	$ 15,678,317,000	$ 11,958,873,000
Purchased Loans
Loans purchased during the period	776,700,000
Carrying amount of loans purchased during the period	759,300,000
Percentage of purchased loans classified as student loans	63.00%
Percentage of purchased loans classified as premium financing loans	36.00%
Percentage of purchased loans classified as other loans	1.00%
Loans Held for Sale
Total loans held for sale	204,970,000	174,317,000
Proceeds from the sales of Loans held for sale, including loans reclassified to loans held for sale	117,300,000	351,900,000	652,700,000
Net gain from sale of loans held for sale during the period	4,000,000	14,600,000	14,500,000
Loans receivable reclassified to loans held for sale	97,065,000	144,131,000	644,915,000
Residential
Credit Risk and Concentrations
Loans receivable, excluding covered loans, gross	4,185,309,000	3,088,031,000
Commercial Real Estate ("CRE")
Credit Risk and Concentrations
Loans receivable, excluding covered loans, gross	$ 4,585,077,000	$ 3,894,695,000