cm:Concept: us-gaap:RetailLandSalesMaturityOfAccountsReceivableYearFour
| Retail Land Sales, Maturity of Accounts Receivable, Year Four |
| us-gaap:RetailLandSalesMaturityOfAccountsReceivableYearFour |
| Amount of accounts receivable from retail land sales to be collected in the fourth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| As Of (instant) |
| Debit |
| false |
| us-gaap:RetailLandSalesMaturityOfAccountsReceivableYearFour |