Property, Plant and Equipment
Property, plant and equipment are stated at cost less accumulated depreciation and amortization. Depreciation and amortization are provided on the straight-line method by charges to operations at rates based upon the expected useful lives of individual or groups of assets (15 to 20 years for land and land improvements; 20 to 40 years for buildings; 5 to 20 years for machinery and equipment; and 3 to 10 years for office and other). The cost and related accumulated depreciation and amortization of assets sold or otherwise disposed of are removed from the related accounts and resulting gains or losses are reflected in operations. Expenditures for maintenance and minor repairs and renewals are expensed, while costs of major repairs and betterments are capitalized and amortized on a straight-line basis over the period of time estimated to lapse until the next major repair occurs.
Property, plant and equipment and other long-lived assets are reviewed in order to assess recoverability based on projected income and related cash flows on an undiscounted basis when triggering events occur. Should the sum of the expected future net cash flows be less than the carrying value, an impairment loss would be recognized. An impairment loss would be measured by the amount by which the carrying value of the asset exceeds the fair value of the asset.
We have asset retirement obligations with respect to certain of our refineries and related assets due to various legal obligations to clean and/or dispose of various component parts at the time they are retired. However, these assets can be used for extended and indeterminate periods of time, as long as they are properly maintained and/or upgraded. It is our practice and current intent to maintain refineries and related assets and to continue making improvements to those assets based on technological advances. As a result, we believe our refineries and related assets have indeterminate lives for purposes of estimating asset retirement obligations because dates or ranges of dates upon which we would retire a refinery and related assets cannot reasonably be estimated at this time. When a date or range of dates can reasonably be estimated for the retirement of any component part of a refinery or related asset, we will estimate the cost of performing the retirement activities and record a liability for the fair value of that cost using established present value techniques.
