XML 77 R84.htm IDEA: XBRL DOCUMENT
v3.3.0.814

BUSINESS SEGMENTS (Details) | 9 Months Ended
--- | ---
Sep. 30, 2015 segment business_division
Segment Reporting [Abstract] |
Number of operating segments | 3
Number of business divisions | business_division | 3
Number of segment whom broad administrative support are provided | 2

X
- Definition The total number of business divisions that meet the criteria of an operating segment. + References No definition available. + Details
Name: | ewbc_NumberOfBusinessDivisions
Namespace Prefix: | ewbc_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the number of segments that are provided broad administrative support. + References No definition available. + Details
Name: | ewbc_NumberOfSegmentWhomBroadAdministrativeSupportProvided
Namespace Prefix: | ewbc_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues. + References No definition available. + Details
Name: | us-gaap_NumberOfOperatingSegments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

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