cm:Concept: us-gaap:ValuationAllowanceCommentary
| Valuation Allowance, Commentary |
| us-gaap:ValuationAllowanceCommentary |
| Describes the facts and circumstances that resulted in an assessment that it is more likely than not that all or a portion of that deferred tax asset will not be realized. Includes in this description the following: (1) the amount of taxable income and the periods over which it must be earned to allow for the realization of the deferred tax asset; (2) actual levels of past taxable income; (3) reasons for significant differences in actual levels of past taxable income and pretax book income; and (4) known trends, events or transactions that are expected to affect future levels of taxable income. |
| cm:Concept |
| Text/String (xbrli:stringItemType) |
| For Period (duration) |
| (no balance type) |
| false |
| us-gaap:ValuationAllowanceCommentary |