NON-COVERED LOANS AND ALLOWANCE FOR LOAN LOSSES (Details 4) (USD $)	12 Months Ended
	Dec. 31, 2013 item	Dec. 31, 2012 item
Credit Quality Indicators
Number of grades in the risk rating system utilized by the company to rate credit risk of loans receivable	8
Increase (decrease) in non-covered loans graded Substandard	$ 29,300,000
Percentage increase (decrease) in non-covered loans graded Substandard	6.00%
Number of doubtful or loss grade loans	0	0
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	15,678,317,000	11,958,873,000
Pass/Watch
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	14,991,479,000	11,253,469,000
Special Mention
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	197,284,000	186,560,000
Substandard
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	489,554,000	518,844,000
Residential
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	4,185,309,000	3,088,031,000
Residential | Residential Single-family
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	3,192,875,000	2,187,323,000
Residential | Residential Single-family | Pass/Watch
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	3,167,337,000	2,163,918,000
Residential | Residential Single-family | Special Mention
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	8,331,000	5,131,000
Residential | Residential Single-family | Substandard
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	17,207,000	18,274,000
Residential | Residential Multifamily
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	992,434,000	900,708,000
Residential | Residential Multifamily | Pass/Watch
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	923,697,000	781,552,000
Residential | Residential Multifamily | Special Mention
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	1,634,000	13,510,000
Residential | Residential Multifamily | Substandard
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	67,103,000	105,646,000
Commercial Real Estate ("CRE")
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	4,585,077,000	3,894,695,000
Commercial Real Estate ("CRE") | Income producing
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	4,301,030,000	3,644,035,000
Commercial Real Estate ("CRE") | Income producing | Pass/Watch
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	4,032,269,000	3,416,142,000
Commercial Real Estate ("CRE") | Income producing | Special Mention
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	56,752,000	42,222,000
Commercial Real Estate ("CRE") | Income producing | Substandard
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	212,009,000	185,671,000
Commercial Real Estate ("CRE") | Construction
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	140,186,000	121,589,000
Commercial Real Estate ("CRE") | Construction | Pass/Watch
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	127,138,000	63,008,000
Commercial Real Estate ("CRE") | Construction | Special Mention
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	6,160,000	16,885,000
Commercial Real Estate ("CRE") | Construction | Substandard
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	6,888,000	41,696,000
Commercial Real Estate ("CRE") | Land
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	143,861,000	129,071,000
Commercial Real Estate ("CRE") | Land | Pass/Watch
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	116,000,000	79,085,000
Commercial Real Estate ("CRE") | Land | Special Mention
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	9,304,000	13,232,000
Commercial Real Estate ("CRE") | Land | Substandard
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	18,557,000	36,754,000
Commercial and Industrial ("C&I")
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	5,360,193,000	4,231,265,000
Commercial and Industrial ("C&I") | Commercial Business
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	4,637,056,000	3,569,388,000
Commercial and Industrial ("C&I") | Commercial Business | Pass/Watch
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	4,400,847,000	3,380,212,000
Commercial and Industrial ("C&I") | Commercial Business | Special Mention
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	92,315,000	69,687,000
Commercial and Industrial ("C&I") | Commercial Business | Substandard
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	143,894,000	119,489,000
Commercial and Industrial ("C&I") | Trade finance
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	723,137,000	661,877,000
Commercial and Industrial ("C&I") | Trade finance | Pass/Watch
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	681,345,000	632,617,000
Commercial and Industrial ("C&I") | Trade finance | Special Mention
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	22,099,000	24,778,000
Commercial and Industrial ("C&I") | Trade finance | Substandard
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	19,693,000	4,482,000
Consumer
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	1,547,738,000	744,882,000
Consumer | Student loans
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	679,220,000	475,799,000
Consumer | Student loans | Pass/Watch
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	677,094,000	475,799,000
Consumer | Student loans | Special Mention
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	445,000
Consumer | Student loans | Substandard
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	1,681,000
Consumer | Other Consumer
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	868,518,000	269,083,000
Consumer | Other Consumer | Pass/Watch
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	865,752,000	261,136,000
Consumer | Other Consumer | Special Mention
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	244,000	1,115,000
Consumer | Other Consumer | Substandard
Credit quality indicator disclosures
Loans receivable, excluding covered loans, gross	$ 2,522,000	$ 6,832,000