Regulatory Requirements and Matters - Regulatory Capital Information (Details) $ in Thousands	Dec. 31, 2025 USD ($)	Dec. 31, 2024 USD ($)
Minimum Regulatory Requirements
Total capital ratio required for capital adequacy to risk weighted assets	0.080
Tier 1 capital ratio required for capital adequacy to risk weighted assets	0.060
Common equity tier 1 capital adequacy to risk weighted assets	0.045
Tier 1 leverage capital (to adjusted quarterly average assets), Ratio (as a percent)	0.040
Well-Capitalized Requirement
Fully phased-in capital conservation buffer	2.50%
Company
Actual
Total capital (to risk-weighted assets), Amount	$ 9,480,208	$ 8,561,797
Tier I capital (to risk-weighted assets), Amount	8,721,523	7,839,816
CET1 capital (to risk-weighted assets), Amount	8,721,523	7,839,816
Tier 1 leverage capital (to adjusted quarterly average assets), Amount	$ 8,721,523	$ 7,839,816
Total capital (to risk-weighted assets), Ratio (as a percent)	0.164	0.156
Tier I capital (to risk-weighted assets), Ratio (as a percent)	0.151	0.143
CET1 capital (to risk-weighted assets), Ratio (as a percent)	0.151	0.143
Tier 1 leverage capital (to adjusted quarterly average assets), Ratio (as a percent)	0.109	0.104
Minimum Regulatory Requirements
Total capital ratio required for capital adequacy to risk weighted assets	0.080
Tier 1 capital ratio required for capital adequacy to risk weighted assets	0.060
Common equity tier 1 capital adequacy to risk weighted assets	0.045
Tier 1 leverage capital (to adjusted quarterly average assets), Ratio (as a percent)	0.040
Minimum Regulatory Requirements including Capital Conservation Buffer
Total capital (to risk-weighted assets), Ratio (as a percent)	10.50%
Tier I capital (to risk-weighted assets), Ratio (as a percent)	8.50%
CET1 capital (to risk-weighted assets), Ratio (as a percent)	7.00%
Tier 1 leverage capital (to adjusted quarterly average assets), Ratio (as a percent)	4.00%
Well-Capitalized Requirement
Total capital (to risk-weighted assets), Ratio (as a percent)	0.100
Tier I capital (to risk-weighted assets), Ratio (as a percent)	0.060
East West Bank
Actual
Total capital (to risk-weighted assets), Amount	$ 8,694,701	$ 8,053,389
Tier I capital (to risk-weighted assets), Amount	7,973,536	7,367,996
CET1 capital (to risk-weighted assets), Amount	7,973,536	7,367,996
Tier 1 leverage capital (to adjusted quarterly average assets), Amount	$ 7,973,536	$ 7,367,996
Total capital (to risk-weighted assets), Ratio (as a percent)	0.151	0.147
Tier I capital (to risk-weighted assets), Ratio (as a percent)	0.139	0.134
CET1 capital (to risk-weighted assets), Ratio (as a percent)	0.139	0.134
Tier 1 leverage capital (to adjusted quarterly average assets), Ratio (as a percent)	0.100	0.098
Minimum Regulatory Requirements
Total capital ratio required for capital adequacy to risk weighted assets	0.080
Tier 1 capital ratio required for capital adequacy to risk weighted assets	0.060
Common equity tier 1 capital adequacy to risk weighted assets	0.045
Tier 1 leverage capital (to adjusted quarterly average assets), Ratio (as a percent)	0.040
Minimum Regulatory Requirements including Capital Conservation Buffer
Total capital (to risk-weighted assets), Ratio (as a percent)	10.50%
Tier I capital (to risk-weighted assets), Ratio (as a percent)	8.50%
CET1 capital (to risk-weighted assets), Ratio (as a percent)	7.00%
Tier 1 leverage capital (to adjusted quarterly average assets), Ratio (as a percent)	4.00%
Well-Capitalized Requirement
Total capital (to risk-weighted assets), Ratio (as a percent)	0.100
Tier I capital (to risk-weighted assets), Ratio (as a percent)	0.080
CET1 capital (to risk-weighted assets), Ratio (as a percent)	0.065
Tier 1 leverage capital (to adjusted quarterly average assets), Ratio (as a percent)	0.050