LOANS RECEIVABLE AND ALLOWANCE FOR CREDIT LOSSES (Details 3) - Loans Receivable - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Recorded Investment [Line Items]
Total loans	$ 25,503,139	$ 23,643,748
CRE
Financing Receivable, Recorded Investment [Line Items]
Total loans	8,690,863	8,100,072
CRE | Income producing
Financing Receivable, Recorded Investment [Line Items]
Total loans	8,016,109	7,471,812
CRE | Construction
Financing Receivable, Recorded Investment [Line Items]
Total loans	551,560	434,623
CRE | Land
Financing Receivable, Recorded Investment [Line Items]
Total loans	123,194	193,637
C&I
Financing Receivable, Recorded Investment [Line Items]
Total loans	9,640,563	8,991,535
C&I | Commercial business
Financing Receivable, Recorded Investment [Line Items]
Total loans	8,959,633	8,201,764
C&I | Trade finance
Financing Receivable, Recorded Investment [Line Items]
Total loans	680,930	789,771
Residential
Financing Receivable, Recorded Investment [Line Items]
Total loans	5,095,718	4,594,336
Residential | Real estate loan | Single-family
Financing Receivable, Recorded Investment [Line Items]
Total loans	3,509,779	3,069,969
Residential | Real estate loan | Multifamily
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,585,939	1,524,367
Consumer
Financing Receivable, Recorded Investment [Line Items]
Total loans	2,075,995	1,957,805
Non-PCI Loans
Financing Receivable, Recorded Investment [Line Items]
Total loans	24,860,694	22,672,994
Non-PCI Loans | Pass/Watch
Financing Receivable, Recorded Investment [Line Items]
Total loans	24,177,983	21,892,052
Non-PCI Loans | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	212,927	287,566
Non-PCI Loans | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	464,609	468,937
Non-PCI Loans | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total loans	5,167	24,416
Non-PCI Loans | Loss
Financing Receivable, Recorded Investment [Line Items]
Total loans	8	23
Non-PCI Loans | CRE
Financing Receivable, Recorded Investment [Line Items]
Total loans	8,340,497	7,550,707
Non-PCI Loans | CRE | Income producing
Financing Receivable, Recorded Investment [Line Items]
Total loans	7,667,661	6,930,537
Non-PCI Loans | CRE | Income producing | Pass/Watch
Financing Receivable, Recorded Investment [Line Items]
Total loans	7,476,804	6,665,994
Non-PCI Loans | CRE | Income producing | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	29,005	59,290
Non-PCI Loans | CRE | Income producing | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	161,852	205,238
Non-PCI Loans | CRE | Income producing | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Non-PCI Loans | CRE | Income producing | Loss
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	15
Non-PCI Loans | CRE | Construction
Financing Receivable, Recorded Investment [Line Items]
Total loans	551,560	432,728
Non-PCI Loans | CRE | Construction | Pass/Watch
Financing Receivable, Recorded Investment [Line Items]
Total loans	551,560	431,100
Non-PCI Loans | CRE | Construction | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	1,158
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 | Construction | Loss
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Non-PCI Loans | CRE | Land
Financing Receivable, Recorded Investment [Line Items]
Total loans	121,276	187,442
Non-PCI Loans | CRE | Land | Pass/Watch
Financing Receivable, Recorded Investment [Line Items]
Total loans	107,976	172,093
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	13,290	15,349
Non-PCI Loans | CRE | Land | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total loans	10	0
Non-PCI Loans | CRE | Land | Loss
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Non-PCI Loans | C&I
Financing Receivable, Recorded Investment [Line Items]
Total loans	9,602,176	8,932,319
Non-PCI Loans | C&I | Commercial business
Financing Receivable, Recorded Investment [Line Items]
Total loans	8,921,246	8,143,858
Non-PCI Loans | C&I | Commercial business | Pass/Watch
Financing Receivable, Recorded Investment [Line Items]
Total loans	8,559,674	7,780,686
Non-PCI Loans | C&I | Commercial business | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	155,276	201,016
Non-PCI Loans | C&I | Commercial business | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	201,139	137,740
Non-PCI Loans | C&I | Commercial business | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total loans	5,157	24,416
Non-PCI Loans | C&I | Commercial business | Loss
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Non-PCI Loans | C&I | Trade finance
Financing Receivable, Recorded Investment [Line Items]
Total loans	680,930	788,461
Non-PCI Loans | C&I | Trade finance | Pass/Watch
Financing Receivable, Recorded Investment [Line Items]
Total loans	635,027	750,770
Non-PCI Loans | C&I | Trade finance | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	9,435	13,836
Non-PCI Loans | C&I | Trade finance | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	36,460	23,847
Non-PCI Loans | C&I | Trade finance | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Non-PCI Loans | C&I | Trade finance | Loss
Financing Receivable, Recorded Investment [Line Items]
Total loans	8	8
Non-PCI Loans | Residential
Financing Receivable, Recorded Investment [Line Items]
Total loans	4,860,954	4,256,426
Non-PCI Loans | Residential | Real estate loan | Single-family
Financing Receivable, Recorded Investment [Line Items]
Total loans	3,370,669	2,880,336
Non-PCI Loans | Residential | Real estate loan | Single-family | Pass/Watch
Financing Receivable, Recorded Investment [Line Items]
Total loans	3,341,015	2,844,758
Non-PCI Loans | Residential | Real estate loan | Single-family | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	10,179	8,092
Non-PCI Loans | Residential | Real estate loan | Single-family | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	19,475	27,486
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 | Single-family | Loss
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	1,490,285	1,376,090
Non-PCI Loans | Residential | Real estate loan | Multifamily | Pass/Watch
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,462,522	1,318,896
Non-PCI Loans | Residential | Real estate loan | Multifamily | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	2,268	2,928
Non-PCI Loans | Residential | Real estate loan | Multifamily | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	25,495	54,266
Non-PCI Loans | Residential | Real estate loan | Multifamily | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Non-PCI Loans | Residential | Real estate loan | Multifamily | Loss
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Non-PCI Loans | Consumer
Financing Receivable, Recorded Investment [Line Items]
Total loans	2,057,067	1,933,542
Non-PCI Loans | Consumer | Pass/Watch
Financing Receivable, Recorded Investment [Line Items]
Total loans	2,043,405	1,927,755
Non-PCI Loans | Consumer | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	6,764	1,246
Non-PCI Loans | Consumer | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	6,898	4,541
Non-PCI Loans | Consumer | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Non-PCI Loans | Consumer | Loss
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
PCI Loans
Financing Receivable, Recorded Investment [Line Items]
Total loans	642,445	970,754
PCI Loans | Pass/Watch
Financing Receivable, Recorded Investment [Line Items]
Total loans	568,844	835,890
PCI Loans | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	5,566	7,551
PCI Loans | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	68,035	127,313
PCI Loans | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
PCI Loans | Loss
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
PCI Loans | CRE
Financing Receivable, Recorded Investment [Line Items]
Total loans	350,366	549,365
PCI Loans | CRE | Income producing
Financing Receivable, Recorded Investment [Line Items]
Total loans	348,448	541,275
PCI Loans | CRE | Income producing | Pass/Watch
Financing Receivable, Recorded Investment [Line Items]
Total loans	293,529	440,100
PCI Loans | CRE | Income producing | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	3,239	4,987
PCI Loans | CRE | Income producing | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	51,680	96,188
PCI Loans | CRE | Income producing | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
PCI Loans | CRE | Income producing | Loss
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
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 | Construction | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
PCI Loans | CRE | Construction | Loss
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
PCI Loans | CRE | Land
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,918	6,195
PCI Loans | CRE | Land | Pass/Watch
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,562	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	356	1,910
PCI Loans | CRE | Land | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
PCI Loans | CRE | Land | Loss
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
PCI Loans | C&I
Financing Receivable, Recorded Investment [Line Items]
Total loans	38,387	59,216
PCI Loans | C&I | Commercial business
Financing Receivable, Recorded Investment [Line Items]
Total loans	38,387	57,906
PCI Loans | C&I | Commercial business | Pass/Watch
Financing Receivable, Recorded Investment [Line Items]
Total loans	33,885	52,212
PCI Loans | C&I | Commercial business | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	772	819
PCI Loans | C&I | Commercial business | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	3,730	4,875
PCI Loans | C&I | Commercial business | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
PCI Loans | C&I | Commercial business | Loss
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
PCI Loans | C&I | Trade finance
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	1,310
PCI Loans | C&I | Trade finance | Pass/Watch
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	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 | C&I | Trade finance | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
PCI Loans | C&I | Trade finance | Loss
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
PCI Loans | Residential
Financing Receivable, Recorded Investment [Line Items]
Total loans	234,764	337,910
PCI Loans | Residential | Real estate loan | Single-family
Financing Receivable, Recorded Investment [Line Items]
Total loans	139,110	189,633
PCI Loans | Residential | Real estate loan | Single-family | Pass/Watch
Financing Receivable, Recorded Investment [Line Items]
Total loans	136,245	184,092
PCI Loans | Residential | Real estate loan | Single-family | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,239	1,293
PCI Loans | Residential | Real estate loan | Single-family | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,626	4,248
PCI Loans | Residential | Real estate loan | Single-family | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
PCI Loans | Residential | Real estate loan | Single-family | Loss
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
PCI Loans | Residential | Real estate loan | Multifamily
Financing Receivable, Recorded Investment [Line Items]
Total loans	95,654	148,277
PCI Loans | Residential | Real estate loan | Multifamily | Pass/Watch
Financing Receivable, Recorded Investment [Line Items]
Total loans	86,190	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	9,464	17,507
PCI Loans | Residential | Real estate loan | Multifamily | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
PCI Loans | Residential | Real estate loan | Multifamily | Loss
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
PCI Loans | Consumer
Financing Receivable, Recorded Investment [Line Items]
Total loans	18,928	24,263
PCI Loans | Consumer | Pass/Watch
Financing Receivable, Recorded Investment [Line Items]
Total loans	17,433	23,121
PCI Loans | Consumer | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	316	452
PCI Loans | Consumer | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,179	690
PCI Loans | Consumer | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
PCI Loans | Consumer | Loss
Financing Receivable, Recorded Investment [Line Items]
Total loans	$ 0	$ 0