BASIS OF PRESENTATION (Policies)	6 Months Ended
BASIS OF PRESENTATION (Policies)	Jun. 30, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Consolidation	The unaudited interim Consolidated Financial Statements in this Form 10-Q include the accounts of East West and its subsidiaries, East West Bank and subsidiaries (referred to herein as “East West Bank” or the “Bank”) and East West Insurance Services, Inc. Intercompany transactions and balances have been eliminated in consolidation. As of June 30, 2016, East West has six wholly-owned subsidiaries that are statutory business trusts (the “Trusts”). In accordance with FASB Accounting Standards Codification (“ASC”) Topic 810, the Trusts are not consolidated into the Company.
Basis of Presentation	The unaudited interim Consolidated Financial Statements presented in accordance with United States Generally Accepted Accounting Principles (“U.S. GAAP”), applicable guidelines prescribed by regulatory authorities, and general practices within the banking industry, reflect all adjustments that, in the opinion of management, are necessary for fair statement of the interim period financial statements. Certain prior year balances and notes have been reclassified to conform to current period presentation.
Current Accounting Developments	NEW ACCOUNTING PRONOUNCEMENTS ADOPTED In February 2015, the FASB issued Accounting Standards Update (“ASU”) 2015-02, Consolidation (Topic 810): Amendments to the Consolidation Analysis that changes the analysis a reporting entity must perform to determine whether it should consolidate certain types of legal entities. The amended guidance 1) modifies the evaluation of whether limited partnerships and similar legal entities are VIEs or voting interest entities; 2) eliminates the presumption that a general partner should consolidate a limited partnership; 3) affects the consolidation analysis of reporting entities that are involved with VIEs, particularly those that have fee arrangements and related party relationships; and 4) provides a scope exception from consolidation guidance for reporting entities that are required to comply with or operate in accordance with requirements that are similar to those in Rule 2a7 of the Investment Company Act of 1940 for registered money market funds. The Company adopted this amended guidance in the first quarter of 2016 and the adoption of this guidance did not have a material impact on the Company’s Consolidated Financial Statements. In April 2015, the FASB issued ASU 2015-03, Interest-Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs. ASU 2015-03 simplifies the presentation of debt issuance costs related to a recognized debt liability to be presented in the balance sheet as a direct deduction from the carrying amount of debt liability, consistent with debt discounts. The Company adopted this guidance retrospectively in the first quarter of 2016. The adoption of this guidance did not have a material impact on the Company’s Consolidated Financial Statements. In April 2015, the FASB issued ASU 2015-05, Intangibles-Goodwill and Other-Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Fees Paid in a Cloud Computing Arrangement. ASU 2015-05 amends ASC 350-40 and requires the Company to determine whether a cloud computing arrangement contains a software license. If the arrangement contains a software license, the Company should account for the fees related to the software license element consistent with how the acquisitions of other software licenses are accounted for under ASC 350-40. If the arrangement does not contain a software license, the Company should account for the arrangement as a service contract. The Company adopted this guidance prospectively to all arrangements entered into or materially modified in the first quarter of 2016. The adoption of this guidance did not have a material impact on the Company’s Consolidated Financial Statements. RECENT ACCOUNTING PRONOUNCEMENTS In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606). The new guidance replaces existing revenue recognition guidance for contracts to provide goods or services to customers and amends existing guidance related to recognition of gains and losses on the sale of certain nonfinancial assets such as real estate. ASU 2014-09 clarifies the principles for recognizing revenue and replaces nearly all existing revenue recognition guidance in U.S. GAAP. Quantitative and qualitative disclosures regarding the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers are also required. ASU 2014-09 as amended by ASU 2015-14, ASU 2016-08, ASU 2016-10 and ASU 2016-12, is effective for interim and annual periods beginning after December 15, 2017 and is applied on either a modified retrospective or full retrospective basis. Early adoption is permitted for interim and annual periods beginning after December 15, 2016. The Company’s preliminary analysis suggests that the adoption of this accounting guidance is not expected to have a material impact on the Company’s Consolidated Financial Statements. However, there are many aspects of the new accounting guidance that are still being interpreted and the FASB has recently issued updates to certain aspects of guidance. The results of our materiality analysis may change based on the conclusion reached as to the application of the new guidance. In January 2016, the FASB issued ASU 2016-01, Financial Instruments—Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities. ASU 2016-01 requires equity investments, except those accounted for under the equity method of accounting or consolidated, to be measured at fair value with changes recognized in net income. If there is no readily determinable fair value, the guidance allows entities the ability to measure investments at cost less impairment, whereby impairment is based on a qualitative assessment. The guidance eliminates the requirement to disclose the methods and significant assumptions used to estimate the fair value of financial instruments measured at amortized cost and changes the presentation of financial assets and financial liabilities on the Consolidated Balance Sheet or in the footnotes. If an entity has elected the fair value option to measure liabilities, the new accounting guidance requires the portion of the change in the fair value of a liability resulting from credit risk to be presented in other comprehensive income. The Company has not elected to measure any of its liabilities at fair value. ASU 2016-01 is effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. Early adoption is not permitted except for certain specific changes under the fair value option guidance. To adopt the amendments, the Company is required to make a cumulative-effect adjustment to the consolidated balance sheet as of the beginning of the fiscal year in which the guidance is effective. However, the amendments related to equity securities without readily determinable fair values (including disclosure requirements) should be applied prospectively to equity investments that exist as of the adoption date. The Company is currently evaluating the impact on its Consolidated Financial Statements. In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842), which is intended to increase transparency and comparability in the accounting for lease transactions. ASU 2016-02 requires lessees to recognize all leases longer than twelve months on the Consolidated Balance Sheet as lease assets and lease liabilities and quantitative and qualitative disclosures regarding key information about leasing arrangements. Lessor accounting is largely unchanged. ASU 2016-02 is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years with an option to early adopt. The Company is currently evaluating the impact on its Consolidated Financial Statements. In March 2016, the FASB issued ASU 2016-05, Derivatives and Hedging (Topic 815): Effect of Derivative Contract Novations on Existing Hedge Accounting Relationships, to clarify that a change in the counterparty to a derivative instrument that has been designated as the hedging instrument in an existing hedging relationship would not be considered a termination of the derivative instrument or a change in a critical term of the hedging relationship provided that all other hedge accounting criteria in ASC 815 continue to be met. This clarification applies to both cash flow and fair value hedging relationships. ASU 2016-05 is effective for fiscal years beginning after December 15, 2016, including interim periods within those fiscal years with an option to early adopt. The Company has an option to adopt the amendments of this ASU either on a prospective basis or modified retrospective basis. The Company does not expect the adoption of this guidance to have a material impact on its Consolidated Financial Statements. In March 2016, the FASB issued ASU 2016-06, Derivatives and Hedging (Topic 815): Contingent Put and Call Options in Debt Instruments that requires an entity to use a four step decision model when assessing contingent call (put) options that can accelerate the payment of principal on debt instruments to determine whether they are clearly and closely related to their debt hosts. ASU 2016-06 will be effective for interim and annual reporting periods beginning after December 15, 2016 and must be implemented using a modified retrospective basis. Early adoption is permitted. The Company does not expect the adoption of this guidance to have a material impact on its Consolidated Financial Statements. In March 2016, the FASB issued ASU 2016-07, Investments—Equity Method and Joint Ventures (Topic 323): Simplifying the Transition to the Equity Method of Accounting, to eliminate the requirement for an investor to retroactively apply the equity method when its increase in ownership interest (or degree of influence) in an investee triggers equity method accounting. The amendments in ASU 2016-07 also require that an entity that has an available-for-sale equity security that becomes qualified for the equity method of accounting recognize through earnings the unrealized holding gain or loss in AOCI at the date the investment becomes qualified for use of the equity method. ASU 2016-07 is effective for fiscal years beginning after December 15, 2016, including interim periods within those fiscal years and should be applied prospectively. Early adoption is not permitted. The Company is currently evaluating the impact on its Consolidated Financial Statements. In March 2016, the FASB issued ASU 2016-09, Compensation—Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting, to simplify several aspects of the accounting for share-based payment transactions, including the accounting for income taxes, forfeitures, statutory tax withholding requirements, as well as classification in the statement of cash flows. ASU 2016-09 also eliminated certain guidance in ASC 718 on when awards cease to be within the scope of ASC 718 and instead become subject to other U.S. GAAP requirements. ASU 2016-09 is effective for fiscal years beginning after December 15, 2016, including interim periods within those fiscal years. Early adoption is permitted. The Company is currently evaluating the impact on its Consolidated Financial Statements. In June 2016, the FASB issued ASU 2016-13 Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments to introduce a new approach based on expected losses to estimate credit losses on certain types of financial instruments, which modifies the impairment model for available-for-sale debt securities and provides for a simplified accounting model for purchased financial assets with credit deterioration since their origination. The new “expected credit loss” impairment model will apply to most financial assets measured at amortized cost and certain other instruments, including trade and other receivables, loans, held-to-maturity debt securities, net investments in leases and off-balance-sheet credit exposures. ASU 2016-13 also expands the disclosure requirements regarding an entity’s assumptions, models and methods for estimating the allowance for loans and lease losses and requires disclosure of the amortized cost balance for each class of financial asset by credit quality indicator, disaggregated by the year of origination (i.e., by vintage year). ASU 2016-13 is effective for the fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. Earlier adoption is permitted as of the fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. The Company is currently evaluating the impact on its Consolidated Financial Statements.
Credit Quality Indicators	Credit Quality Indicators All loans are subject to the Company’s internal and external credit review and monitoring. Loans are risk rated based on an analysis of the current state of the borrower’s credit quality. The analysis of credit quality includes a review of all repayment sources, the borrower’s current payment performance/delinquency, current financial and liquidity status and all other relevant information. For single-family residential loans, payment performance/delinquency is the driving indicator for the risk ratings. Risk ratings are the overall credit quality indicator for the Company and the credit quality indicator utilized for estimating the appropriate allowance for loan losses. The Company utilizes a risk rating system, which can be classified within the following categories: Pass, Watch, Special Mention, Substandard, Doubtful and Loss. The risk ratings reflect the relative strength of the repayment sources. Pass and Watch loans are generally considered to have sufficient sources of repayment in order to repay the loan in full in accordance with all terms and conditions. These borrowers may have some credit risks that require monitoring, but full repayments are expected. Special Mention loans are considered to have potential weaknesses that warrant closer attention by management. Special Mention is considered a transitory grade. If potential weaknesses are resolved, the loan is upgraded to a Pass or Watch grade. If negative trends in the borrower’s financial status or other information indicates that the repayment sources may become inadequate, the loan is downgraded to a Substandard grade. Substandard loans are considered to have well-defined weaknesses that jeopardize the full and timely repayment of the loan. Substandard loans have a distinct possibility of loss, if the deficiencies are not corrected. Additionally, when management has assessed a potential for loss but a distinct possibility of loss is not recognizable, the loan is still classified as Substandard. Doubtful loans have insufficient sources of repayment and a high probability of loss. Loss loans are considered to be uncollectible and of such little value that they are no longer considered bankable assets. These internal risk ratings are reviewed routinely and adjusted based on changes in the borrowers’ financial status and collectability.
Impaired Loans	Impaired Loans The Company’s loans are grouped into heterogeneous and homogeneous (mostly consumer loans) categories. Classified loans in the heterogeneous category are identified and evaluated for impairment on an individual basis. A loan is considered impaired when, based on current information and events, it is probable that the Company will not be able to collect all scheduled payments of principal or interest due in accordance with the original contractual terms. Impaired loans are measured based on the present value of expected future cash flows discounted at the loan’s effective interest rate or, as expedient, at the loan’s observable market price or the fair value of the collateral, if the loan is collateral dependent, less costs to sell. When the value of an impaired loan is less than the recorded investment and the loan is classified as nonperforming and uncollectible, the deficiency is charged-off against the allowance for loan losses. Impaired loans exclude the homogeneous consumer loan portfolio, which is evaluated collectively for impairment. The Company’s impaired loans include predominantly non-PCI loans held-for-investment on nonaccrual status and any non-PCI loans modified in a TDR, which may be on accrual or nonaccrual status.
Investments in Qualified Affordable Housing Partnerships, Net	Investments in Qualified Affordable Housing Partnerships, Net The Company records its investments in qualified affordable housing partnerships, net using the proportional amortization method. Under the proportional amortization method, the Company amortizes the initial cost of the investment in proportion to the tax credits and other tax benefits received, and recognizes the amortization on the Consolidated Statements of Income as a component of income tax expense.
Goodwill and Premiums on Acquired Deposits	Premiums on Acquired Deposits Premiums on acquired deposits represent the intangible value of depositor relationships resulting from deposit liabilities assumed in various acquisitions. These intangibles are tested for impairment on an annual basis, or more frequently as events occur, or as current circumstances and conditions warrant. Goodwill Total goodwill of $469.4 million remained unchanged as of June 30, 2016 compared to December 31, 2015. Goodwill is tested for impairment on an annual basis as of December 31^st, or more frequently as events occur or circumstances change that would more likely than not reduce the fair value of a reporting unit below its carrying amount.