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Regulatory Requirements and Matters (Details) - USD ($) | 12 Months Ended
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Dec. 31, 2021 | Dec. 31, 2020
Capital adequacy |  |
Tier One Common Equity For Capital Adequacy To Risk Weighted Assets, Minimum | 4.50% |
Banking Regulation, Tier One Risk-Based Capital Ratio, Capital Adequacy, 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% |
East West Bank |  |
Capital adequacy |  |
Tier One Common Equity For Capital Adequacy To Risk Weighted Assets, Minimum | 4.50% |
Banking Regulation, Tier One Risk-Based Capital Ratio, Capital Adequacy, 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 |
Daily average reserve requirement | $ 0 | $ 0

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- Definition Ratio of minimum total 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 http://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 http://asc.fasb.org/extlink&oid=117337116&loc=SL5958568-112826 + Details
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