LOANS RECEIVABLE AND ALLOWANCE FOR CREDIT LOSSES (Details 3) - Loans Receivable - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Financing Receivable, Recorded Investment [Line Items]
Total loans	$ 24,724,591	$ 23,659,761
CRE
Financing Receivable, Recorded Investment [Line Items]
Total loans	8,515,079	8,110,749
CRE | Income producing
Financing Receivable, Recorded Investment [Line Items]
Total loans	7,780,775	7,478,474
CRE | Construction
Financing Receivable, Recorded Investment [Line Items]
Total loans	600,803	438,671
CRE | Land
Financing Receivable, Recorded Investment [Line Items]
Total loans	133,501	193,604
C&I
Financing Receivable, Recorded Investment [Line Items]
Total loans	9,358,045	9,003,007
C&I | Commercial business
Financing Receivable, Recorded Investment [Line Items]
Total loans	8,683,442	8,213,897
C&I | Trade finance
Financing Receivable, Recorded Investment [Line Items]
Total loans	674,603	789,110
Residential
Financing Receivable, Recorded Investment [Line Items]
Total loans	4,771,993	4,589,914
Residential | Real estate loan | Single-family
Financing Receivable, Recorded Investment [Line Items]
Total loans	3,351,867	3,066,919
Residential | Real estate loan | Multifamily
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,420,126	1,522,995
Consumer
Financing Receivable, Recorded Investment [Line Items]
Total loans	2,079,474	1,956,091
Non-PCI Loans
Financing Receivable, Recorded Investment [Line Items]
Total loans	24,007,010	22,689,007
Non-PCI Loans | Pass/Watch
Financing Receivable, Recorded Investment [Line Items]
Total loans	23,281,555	21,910,821
Non-PCI Loans | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	195,825	287,530
Non-PCI Loans | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	511,320	466,129
Non-PCI Loans | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total loans	18,310	24,527
Non-PCI Loans | CRE
Financing Receivable, Recorded Investment [Line Items]
Total loans	8,119,569	7,561,384
Non-PCI Loans | CRE | Income producing
Financing Receivable, Recorded Investment [Line Items]
Total loans	7,387,777	6,937,199
Non-PCI Loans | CRE | Income producing | Pass/Watch
Financing Receivable, Recorded Investment [Line Items]
Total loans	7,175,508	6,672,951
Non-PCI Loans | CRE | Income producing | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	28,052	59,309
Non-PCI Loans | CRE | Income producing | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	184,217	204,939
Non-PCI Loans | CRE | Income producing | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Non-PCI Loans | CRE | Construction
Financing Receivable, Recorded Investment [Line Items]
Total loans	600,803	436,776
Non-PCI Loans | CRE | Construction | Pass/Watch
Financing Receivable, Recorded Investment [Line Items]
Total loans	595,106	435,112
Non-PCI Loans | CRE | Construction | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	5,697	1,194
Non-PCI Loans | CRE | Construction | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	470
Non-PCI Loans | CRE | Construction | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Non-PCI Loans | CRE | Land
Financing Receivable, Recorded Investment [Line Items]
Total loans	130,989	187,409
Non-PCI Loans | CRE | Land | Pass/Watch
Financing Receivable, Recorded Investment [Line Items]
Total loans	117,194	172,189
Non-PCI Loans | CRE | Land | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Non-PCI Loans | CRE | Land | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	13,785	15,220
Non-PCI Loans | CRE | Land | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total loans	10	0
Non-PCI Loans | C&I
Financing Receivable, Recorded Investment [Line Items]
Total loans	9,315,160	8,943,791
Non-PCI Loans | C&I | Commercial business
Financing Receivable, Recorded Investment [Line Items]
Total loans	8,640,569	8,155,991
Non-PCI Loans | C&I | Commercial business | Pass/Watch
Financing Receivable, Recorded Investment [Line Items]
Total loans	8,263,325	7,794,735
Non-PCI Loans | C&I | Commercial business | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	132,512	201,280
Non-PCI Loans | C&I | Commercial business | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	228,368	135,449
Non-PCI Loans | C&I | Commercial business | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total loans	16,364	24,527
Non-PCI Loans | C&I | Trade finance
Financing Receivable, Recorded Investment [Line Items]
Total loans	674,591	787,800
Non-PCI Loans | C&I | Trade finance | Pass/Watch
Financing Receivable, Recorded Investment [Line Items]
Total loans	640,016	750,144
Non-PCI Loans | C&I | Trade finance | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	18,524	13,812
Non-PCI Loans | C&I | Trade finance | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	14,115	23,844
Non-PCI Loans | C&I | Trade finance | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,936	0
Non-PCI Loans | Residential
Financing Receivable, Recorded Investment [Line Items]
Total loans	4,513,103	4,252,004
Non-PCI Loans | Residential | Real estate loan | Single-family
Financing Receivable, Recorded Investment [Line Items]
Total loans	3,201,245	2,877,286
Non-PCI Loans | Residential | Real estate loan | Single-family | Pass/Watch
Financing Receivable, Recorded Investment [Line Items]
Total loans	3,176,832	2,841,722
Non-PCI Loans | Residential | Real estate loan | Single-family | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	7,161	8,134
Non-PCI Loans | Residential | Real estate loan | Single-family | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	17,252	27,430
Non-PCI Loans | Residential | Real estate loan | Single-family | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Non-PCI Loans | Residential | Real estate loan | Multifamily
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,311,858	1,374,718
Non-PCI Loans | Residential | Real estate loan | Multifamily | Pass/Watch
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,264,586	1,317,550
Non-PCI Loans | Residential | Real estate loan | Multifamily | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	2,918
Non-PCI Loans | Residential | Real estate loan | Multifamily | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	47,272	54,250
Non-PCI Loans | Residential | Real estate loan | Multifamily | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Non-PCI Loans | Consumer
Financing Receivable, Recorded Investment [Line Items]
Total loans	2,059,178	1,931,828
Non-PCI Loans | Consumer | Pass/Watch
Financing Receivable, Recorded Investment [Line Items]
Total loans	2,048,988	1,926,418
Non-PCI Loans | Consumer | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	3,879	883
Non-PCI Loans | Consumer | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	6,311	4,527
Non-PCI Loans | Consumer | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
PCI Loans
Financing Receivable, Recorded Investment [Line Items]
Total loans	717,581	970,754
PCI Loans | Pass/Watch
Financing Receivable, Recorded Investment [Line Items]
Total loans	629,453	835,890
PCI Loans | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	9,597	7,551
PCI Loans | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	78,531	127,313
PCI Loans | CRE
Financing Receivable, Recorded Investment [Line Items]
Total loans	395,510	549,365
PCI Loans | CRE | Income producing
Financing Receivable, Recorded Investment [Line Items]
Total loans	392,998	541,275
PCI Loans | CRE | Income producing | Pass/Watch
Financing Receivable, Recorded Investment [Line Items]
Total loans	333,342	440,100
PCI Loans | CRE | Income producing | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	3,474	4,987
PCI Loans | CRE | Income producing | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	56,182	96,188
PCI Loans | CRE | Construction
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	1,895
PCI Loans | CRE | Construction | Pass/Watch
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
PCI Loans | CRE | Construction | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
PCI Loans | CRE | Construction | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	1,895
PCI Loans | CRE | Land
Financing Receivable, Recorded Investment [Line Items]
Total loans	2,512	6,195
PCI Loans | CRE | Land | Pass/Watch
Financing Receivable, Recorded Investment [Line Items]
Total loans	2,134	4,285
PCI Loans | CRE | Land | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
PCI Loans | CRE | Land | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	378	1,910
PCI Loans | C&I
Financing Receivable, Recorded Investment [Line Items]
Total loans	42,885	59,216
PCI Loans | C&I | Commercial business
Financing Receivable, Recorded Investment [Line Items]
Total loans	42,873	57,906
PCI Loans | C&I | Commercial business | Pass/Watch
Financing Receivable, Recorded Investment [Line Items]
Total loans	34,023	52,212
PCI Loans | C&I | Commercial business | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	4,590	819
PCI Loans | C&I | Commercial business | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	4,260	4,875
PCI Loans | C&I | Trade finance
Financing Receivable, Recorded Investment [Line Items]
Total loans	12	1,310
PCI Loans | C&I | Trade finance | Pass/Watch
Financing Receivable, Recorded Investment [Line Items]
Total loans	12	1,310
PCI Loans | C&I | Trade finance | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
PCI Loans | C&I | Trade finance | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
PCI Loans | Residential
Financing Receivable, Recorded Investment [Line Items]
Total loans	258,890	337,910
PCI Loans | Residential | Real estate loan | Single-family
Financing Receivable, Recorded Investment [Line Items]
Total loans	150,622	189,633
PCI Loans | Residential | Real estate loan | Single-family | Pass/Watch
Financing Receivable, Recorded Investment [Line Items]
Total loans	147,768	184,092
PCI Loans | Residential | Real estate loan | Single-family | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,216	1,293
PCI Loans | Residential | Real estate loan | Single-family | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,638	4,248
PCI Loans | Residential | Real estate loan | Multifamily
Financing Receivable, Recorded Investment [Line Items]
Total loans	108,268	148,277
PCI Loans | Residential | Real estate loan | Multifamily | Pass/Watch
Financing Receivable, Recorded Investment [Line Items]
Total loans	93,379	130,770
PCI Loans | Residential | Real estate loan | Multifamily | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
PCI Loans | Residential | Real estate loan | Multifamily | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	14,889	17,507
PCI Loans | Consumer
Financing Receivable, Recorded Investment [Line Items]
Total loans	20,296	24,263
PCI Loans | Consumer | Pass/Watch
Financing Receivable, Recorded Investment [Line Items]
Total loans	18,795	23,121
PCI Loans | Consumer | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	317	452
PCI Loans | Consumer | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	$ 1,184	$ 690