Property, Plant and Equipment—Property, plant and equipment are recorded at cost, including any asset retirement obligations, less accumulated depreciation. For financial reporting, the straight-line method of depreciation is used over the estimated useful lives of 10 to 50 years for buildings and improvements and 2 to 16 years for machinery and equipment. Recognition of the fair value of obligations associated with the retirement of tangible long-lived assets is required when there is a legal obligation to incur such costs. Upon initial recognition of a liability, the cost is capitalized as part of the related long-lived asset and depreciated over the corresponding asset's useful life. See Note 11 Property, Plant and Equipment - Net and Note 17 Other Liabilities for additional details.