Property, Plant and Equipment
Property, plant and equipment are stated at cost. Additions to property, plant and equipment generally include material, labor and overhead. Time Warner also capitalizes certain costs associated with coding, software configuration, upgrades and enhancements incurred for the development of internal use software. Depreciation is recorded on a straight-line basis over estimated useful lives. Leasehold improvements are depreciated over the lesser of the estimated useful life of the improvement or the term of the applicable lease. Time Warner periodically evaluates the depreciation periods of property, plant and equipment to determine whether a revision to its estimates of useful lives is warranted. Property, plant and equipment, including capital leases, consist of (millions):