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Regulatory Requirements and Matters (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2017 | Dec. 31, 2016
Actual |  |
Total Capital (to risk-weighted assets), Amount | $ 3,838,516 | $ 3,400,642
Tier I Capital (to risk-weighted assets), Amount | 3,390,070 | 2,976,002
Tier 1 Common Equity Capital (to risk-weighted assets), Amount | 3,390,070 | 2,976,002
Tier 1 leverage capital (to adjusted average assets), Amount | 3,390,070 | 2,976,002
Risk-weighted assets | 29,669,251 | 27,357,753
Adjusted quarterly average total assets | $ 37,307,975 | $ 34,209,827
Total Capital (to risk-weighted assets), Ratio (as a percent) | 12.90% | 12.40%
Tier I Capital (to risk-weighted assets), Ratio (as a percent) | 11.40% | 10.90%
Tier 1 Common Equity Capital (to risk-weighted assets), Ratio (as a percent) | 11.40% | 10.90%
Tier 1 leverage capital (to adjusted average assets), Ratio (as a percent) | 9.20% | 8.70%
Minimum Requirement |  |
Total Capital (to risk-weighted assets), Ratio (as a percent) | 8.00% | 8.00%
Tier I Capital (to risk-weighted assets), Ratio (as a percent) | 6.00% | 6.00%
Tier 1 Common Equity Capital (to risk-weighted assets), Ratio (as a percent) | 4.50% | 4.50%
Tier 1 leverage capital (to adjusted average assets), Ratio (as a percent) | 4.00% | 4.00%
Well Capitalized Requirement |  |
Total Capital (to risk-weighted assets), Ratio (as a percent) | 10.00% | 10.00%
Tier I Capital (to risk-weighted assets), Ratio (as a percent) | 8.00% | 8.00%
Tier 1 Common Equity Capital (to risk-weighted assets), Ratio (as a percent) | 6.50% | 6.50%
Tier 1 leverage capital (to adjusted average assets), Ratio (as a percent) | 5.00% | 5.00%
East West Bank |  |
Actual |  |
Total Capital (to risk-weighted assets), Amount | $ 3,679,261 | $ 3,371,885
Tier I Capital (to risk-weighted assets), Amount | 3,378,815 | 3,095,245
Tier 1 Common Equity Capital (to risk-weighted assets), Amount | 3,378,815 | 3,095,245
Tier 1 leverage capital (to adjusted average assets), Amount | 3,378,815 | 3,095,245
Risk-weighted assets | 29,643,711 | 27,310,540
Adjusted quarterly average total assets | $ 37,283,273 | $ 34,163,667
Total Capital (to risk-weighted assets), Ratio (as a percent) | 12.40% | 12.30%
Tier I Capital (to risk-weighted assets), Ratio (as a percent) | 11.40% | 11.30%
Tier 1 Common Equity Capital (to risk-weighted assets), Ratio (as a percent) | 11.40% | 11.30%
Tier 1 leverage capital (to adjusted average assets), Ratio (as a percent) | 9.20% | 9.10%
Minimum Requirement |  |
Total Capital (to risk-weighted assets), Ratio (as a percent) | 8.00% | 8.00%
Tier I Capital (to risk-weighted assets), Ratio (as a percent) | 6.00% | 6.00%
Tier 1 Common Equity Capital (to risk-weighted assets), Ratio (as a percent) | 4.50% | 4.50%
Tier 1 leverage capital (to adjusted average assets), Ratio (as a percent) | 4.00% | 4.00%
Well Capitalized Requirement |  |
Total Capital (to risk-weighted assets), Ratio (as a percent) | 10.00% | 10.00%
Tier I Capital (to risk-weighted assets), Ratio (as a percent) | 8.00% | 8.00%
Tier 1 Common Equity Capital (to risk-weighted assets), Ratio (as a percent) | 6.50% | 6.50%
Tier 1 leverage capital (to adjusted average assets), Ratio (as a percent) | 5.00% | 5.00%
Reserve Requirement |  |
Daily average reserve requirement | $ 699,400 | $ 503,800

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