cm:Concept: us-gaap:TierOneRiskBasedCapitalRequiredForCapitalAdequacyToRiskWeightedAssets
| Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets |
| us-gaap:TierOneRiskBasedCapitalRequiredForCapitalAdequacyToRiskWeightedAssets |
| The minimum Tier One Capital Ratio (Tier one capital divided by risk-weighted assets) required for capital adequacy purposes under the regulatory framework for prompt corrective action. |
| cm:Concept |
| Percent (num:percentItemType) |
| As Of (instant) |
| (no balance type) |
| false |
| us-gaap:TierOneRiskBasedCapitalRequiredForCapitalAdequacyToRiskWeightedAssets |