XML 138 R122.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Stockholders’ Equity and Earnings Per Share (Narrative) (Details) - USD ($) | 3 Months Ended | 12 Months Ended |  |  |
--- | --- | --- | --- | --- | ---
Dec. 31, 2017 | Sep. 30, 2017 | Jun. 30, 2017 | Mar. 31, 2017 | Dec. 31, 2016 | Sep. 30, 2016 | Jun. 30, 2016 | Mar. 31, 2016 | Dec. 31, 2015 | Sep. 30, 2015 | Jun. 30, 2015 | Mar. 31, 2015 | Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | Jan. 17, 2014 | Jan. 16, 2014 | Jul. 17, 2013
Warrant |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Shares of East West's common stock into which the warrant may be converted (in shares) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 230,282 |  |
Quarterly Dividends |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends declared per common share (in dollars per share) | $ 0.2 | $ 0.20 | $ 0.20 | $ 0.20 | $ 0.20 | $ 0.20 | $ 0.20 | $ 0.20 |  |  |  |  | $ 0.8 | $ 0.8 | $ 0.8 |  |  |
Total cash dividends paid |  |  |  |  |  |  |  |  |  |  |  |  | $ 116,998,000 | $ 116,595,000 | $ 116,224,000 |  |  |
MetroCorp |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Warrant |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of warrants exercised (in shares) | 0 |  |  |  |  |  |  |  |  |  |  |  | 0 |  |  |  |  |
Common Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Class of Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Amount of stock repurchase authorized by the Board of Directors |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 100,000,000
Purchase of treasury stock pursuant to the Stock Repurchase Program (in shares) |  |  |  |  |  |  |  |  |  |  |  |  | 0 | 0 |  |  |  |
Quarterly Dividends |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends declared per common share (in dollars per share) | $ 0.20 | $ 0.20 | $ 0.20 | $ 0.20 | $ 0.20 | $ 0.20 | $ 0.20 | $ 0.20 | $ 0.20 | $ 0.20 | $ 0.20 | $ 0.20 |  |  |  |  |  |
MetroCorp | MetroCorp |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Warrant |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Shares of East West's common stock into which the warrant may be converted (in shares) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 771,429 |

X
- Definition Represents the number of warrants exercised as of balance sheet date. + References No definition available. + Details
Name: | ewbc_WarrantsExercised
Namespace Prefix: | ewbc_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- 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. + Details
Name: | us-gaap_ClassOfStockLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of securities into which the class of warrant or right may be converted. For example, but not limited to, 500,000 warrants may be converted into 1,000,000 shares. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(i)(2)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 + Details
Name: | us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Aggregate dividends declared during the period for each share of common stock outstanding. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 + Details
Name: | us-gaap_CommonStockDividendsPerShareDeclared
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of paid and unpaid common stock dividends declared with the form of settlement in cash, stock and payment-in-kind (PIK). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 405 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6957935&loc=d3e64057-112817 + Details
Name: | us-gaap_DividendsCommonStock
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_PaymentsOfDividendsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of stock repurchase plan authorized. + References No definition available. + Details
Name: | us-gaap_StockRepurchaseProgramAuthorizedAmount1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Number of shares that have been repurchased during the period and are being held in treasury. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(29)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=84159872&loc=d3e21463-112644 + Details
Name: | us-gaap_TreasuryStockSharesAcquired
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_WarrantsAndRightsNoteDisclosureAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=ewbc_MetroCorpMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementClassOfStockAxis=us-gaap_CommonStockMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=ewbc_MetroCorpMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |