cm:Member: us-gaap:InitialHookupDeferredRevenueMember
| Initial Hookup Deferred Revenue [Member] |
| us-gaap:InitialHookupDeferredRevenueMember |
| Category of deferred revenue by arrangement wherein cable television companies' initial hookup revenue is recognized as revenue to the extent of direct selling costs incurred. The remainder is deferred and amortized to income over the estimated average period that subscribers are expected to remain connected to the system. |
| cm:Member |
| [Member] (nonnum:domainItemType) |
| For Period (duration) |
| (no balance type) |
| true |
| us-gaap:InitialHookupDeferredRevenueMember |