cm:Level2TextBlock: us-gaap:CostMethodInvestmentsPolicy
| Cost Method Investments, Policy [Policy Text Block] |
| us-gaap:CostMethodInvestmentsPolicy |
| Disclosure of accounting policy for the cost method of accounting for investments in common stock or other interests including unconsolidated subsidiaries, corporate joint ventures, noncontrolling interests in real estate ventures, limited partnerships, and limited liability companies. An entity also may describe how such investments are assessed for impairment. |
| cm:Level2TextBlock |
| Text Block (HTML) (nonnum:textBlockItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:CostMethodInvestmentsPolicy |