LOANS RECEIVABLE AND ALLOWANCE FOR CREDIT LOSSES (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2016	Dec. 31, 2015
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Loans, net	$ 25,242,619	$ 23,378,789
Loans Receivable
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Number Of Days Beyond Loan Classified Nonaccrual	90 days
Total loans	$ 25,503,139	23,643,748
Allowance for loan losses	(260,520)	(264,959)
Loans, net	25,242,619	23,378,789
Loans Receivable \| CRE
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	8,690,863	8,100,072
Loans Receivable \| CRE \| Income producing
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	8,016,109	7,471,812
Loans Receivable \| CRE \| Construction
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	551,560	434,623
Loans Receivable \| CRE \| Land
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	123,194	193,637
Loans Receivable \| C&I
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	9,640,563	8,991,535
Loans Receivable \| C&I \| Commercial business
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	8,959,633	8,201,764
Loans Receivable \| C&I \| Trade finance
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	680,930	789,771
Loans Receivable \| Residential
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	5,095,718	4,594,336
Loans Receivable \| Residential \| Real estate loan \| Single-family
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	3,509,779	3,069,969
Loans Receivable \| Residential \| Real estate loan \| Multifamily
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	1,585,939	1,524,367
Loans Receivable \| Consumer
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	2,075,995	1,957,805
Loans Receivable \| Non-PCI Loans
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	24,860,694	22,672,994
Allowance for loan losses	(260,402)	(264,600)
Loans, net	24,600,292	22,408,394
Unearned fees, premiums and discounts, net	1,200	(16,000)
Loans Receivable \| Non-PCI Loans \| CRE
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	8,340,497	7,550,707
Loans Receivable \| Non-PCI Loans \| CRE \| Income producing
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	7,667,661	6,930,537
Loans Receivable \| Non-PCI Loans \| CRE \| Construction
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	551,560	432,728
Loans Receivable \| Non-PCI Loans \| CRE \| Land
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	121,276	187,442
Loans Receivable \| Non-PCI Loans \| C&I
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	9,602,176	8,932,319
Loans Receivable \| Non-PCI Loans \| C&I \| Commercial business
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	8,921,246	8,143,858
Loans Receivable \| Non-PCI Loans \| C&I \| Trade finance
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	680,930	788,461
Loans Receivable \| Non-PCI Loans \| Residential
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	4,860,954	4,256,426
Loans Receivable \| Non-PCI Loans \| Residential \| Real estate loan \| Single-family
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	3,370,669	2,880,336
Loans Receivable \| Non-PCI Loans \| Residential \| Real estate loan \| Multifamily
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	1,490,285	1,376,090
Loans Receivable \| Non-PCI Loans \| Consumer
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	2,057,067	1,933,542
Loans Receivable \| PCI Loans
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	642,445	970,754
Allowance for loan losses	(118)	(359)
Loans, net	642,327	970,395
Loans Receivable \| PCI Loans \| CRE
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	350,366	549,365
Loans Receivable \| PCI Loans \| CRE \| Income producing
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	348,448	541,275
Loans Receivable \| PCI Loans \| CRE \| Construction
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	0	1,895
Loans Receivable \| PCI Loans \| CRE \| Land
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	1,918	6,195
Loans Receivable \| PCI Loans \| C&I
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	38,387	59,216
Loans Receivable \| PCI Loans \| C&I \| Commercial business
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	38,387	57,906
Loans Receivable \| PCI Loans \| C&I \| Trade finance
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	0	1,310
Loans Receivable \| PCI Loans \| Residential
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	234,764	337,910
Loans Receivable \| PCI Loans \| Residential \| Real estate loan \| Single-family
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	139,110	189,633
Loans Receivable \| PCI Loans \| Residential \| Real estate loan \| Multifamily
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	95,654	148,277
Loans Receivable \| PCI Loans \| Consumer
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Total loans	$ 18,928	$ 24,263

The number of days a loan is past due and is placed on nonaccrual status.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

A valuation allowance for financing receivables that are expected to be uncollectible.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=49124121&loc=SL6953423-111524

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- Definition

Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements and loans held for sale.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=28367877&loc=d3e4428-111522

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.7)
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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- Definition

Amount representing an agreement for an unconditional promise by the maker to pay the entity (holder) a definite sum of money at a future date. Such amount may include accrued interest receivable in accordance with the terms of the note. The note also may contain provisions and related items including a discount or premium, payable on demand, secured, or unsecured, interest bearing or noninterest bearing, among a myriad of other features and characteristics. Excludes amounts related to receivables held-for-sale.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.10(3))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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- Definition

Amount of deferred fees paid by borrowers and unamortized costs incurred to originate loans and leases, unamortized loan commitments and loan syndication fees, and premiums over or discounts from face amounts of loans that are being amortized into income as an adjustment to yield. Excludes amounts for loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6378536&loc=d3e10092-111533

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