cm:Concept: us-gaap:LimitedLiabilityCompanyLLCMembersEquityUnitBasedCompensation
| Limited Liability Company (LLC) Members' Equity, Unit-based Payment Arrangement |
| us-gaap:LimitedLiabilityCompanyLLCMembersEquityUnitBasedCompensation |
| Amount of increase (decrease) in members' equity for unit-based payment arrangement issued by limited liability company (LLC). |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| For Period (duration) |
| Credit |
| false |
| us-gaap:LimitedLiabilityCompanyLLCMembersEquityUnitBasedCompensation |