| Cover Page | Jul. 21, 2022 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | Jul. 21, 2022 |
| Entity Registrant Name | EAST WEST BANCORP, INC. |
| Entity Central Index Key | 0001069157 |
| Amendment Flag | false |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 000-24939 |
| Entity Tax Identification Number | 95-4703316 |
| Entity Address, Address Line One | 135 North Los Robles Ave. |
| Entity Address, Address Line Two | 7th Floor |
| Entity Address, City or Town | Pasadena |
| Entity Address, State or Province | CA |
| Entity Address, Postal Zip Code | 91101 |
| City Area Code | 626 |
| Local Phone Number | 768-6000 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, par value $0.001 per share |
| Trading Symbol | EWBC |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
