Regulatory Requirements and Matters - Narrative (Details)	Dec. 31, 2022
Capital adequacy
Banking regulation, tier one risk-based capital ratio, capital a, minimum	0.060
Banking regulation,total risk-based capital ratio, capital adequacy, minimum	0.080
Banking regulation, tier one leverage capital ratio, capital adequacy, minimum	0.040
Fully phased-in capital conservation buffer	2.50%
Common equity tier 1 capital adequacy to risk weighted assets	0.045
East West Bank
Capital adequacy
Banking regulation, tier one risk-based capital ratio, capital a, minimum	0.060
Banking regulation,total risk-based capital ratio, capital adequacy, minimum	0.080
Banking regulation, tier one leverage capital ratio, capital adequacy, minimum	0.040
Tier 1 Common Equity Capital (to risk-weighted assets), Ratio (as a percent)	0.065
Common equity tier 1 capital adequacy to risk weighted assets	0.045

Regulatory Capital, Fully Phased-in Capital Conservation Buffer

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Ratio of minimum Common Equity Tier 1 risk-based capital to risk-weighted assets required for capital adequacy as defined by regulatory framework.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 505
-Section 50
-Paragraph 1B
-URI https://asc.fasb.org/extlink&oid=117337116&loc=SL5958570-112826

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 505
-Section 50
-Paragraph 1
-Subparagraph (c)(1)
-URI https://asc.fasb.org/extlink&oid=117337116&loc=SL5958568-112826

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Ratio of minimum Common Equity Tier 1 risk-based capital to risk-weighted assets categorized as well capitalized as defined by regulatory framework for prompt corrective action.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 505
-Section 50
-Paragraph 1
-Subparagraph (c)(1)
-URI https://asc.fasb.org/extlink&oid=117337116&loc=SL5958568-112826

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Ratio of minimum total risk-based capital to risk-weighted assets required for capital adequacy as defined by regulatory framework.

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Ratio of minimum Tier 1 leverage capital to average assets required for capital adequacy as defined by regulatory framework.

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Ratio of minimum Tier 1 risk-based capital to risk-weighted assets required for capital adequacy as defined by regulatory framework.

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