cm:Concept: us-gaap:NetInvestmentInLeaseOriginatedFiveOrMoreYearsBeforeLatestFiscalYear
| Net Investment in Lease, Originated Five or More Years before Latest Fiscal Year |
| us-gaap:NetInvestmentInLeaseOriginatedFiveOrMoreYearsBeforeLatestFiscalYear |
| Amount of net investment in sales-type and direct financing leases originated five or more years prior to latest fiscal year. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| As Of (instant) |
| Debit |
| false |
| us-gaap:NetInvestmentInLeaseOriginatedFiveOrMoreYearsBeforeLatestFiscalYear |