cm:Concept: us-gaap:AccruedExchangeFeeRebateCurrentAndNoncurrent
| Accrued Exchange Fee Rebate |
| us-gaap:AccruedExchangeFeeRebateCurrentAndNoncurrent |
| Carrying value as of the balance sheet date of obligations incurred through that date and payable for rebates of an exchange fee some mutual funds impose on shareholders if they exchange (transfer) to another fund within the same fund group. |
| cm:Concept |
| Monetary (xbrli:monetaryItemType) |
| As Of (instant) |
| Credit |
| false |
| us-gaap:AccruedExchangeFeeRebateCurrentAndNoncurrent |