Long-Lived Assets:
Property, plant and equipment are stated at historical cost and depreciated by the straight-line method over the estimated useful lives of the assets. Machinery and equipment are depreciated over periods ranging from 3 to 20 years and buildings and building improvements over periods up to 40 years.
We review long-lived assets, including amortizable intangible assets, for impairment when conditions exist that indicate the carrying amount of the assets may not be fully recoverable. We perform undiscounted operating cash flow analyses to determine if an impairment exists. When testing for impairment of assets held for use, we group assets and liabilities at the lowest level for which cash flows are separately identifiable. If an impairment is determined to exist, the loss is calculated based on estimated fair value. Impairment losses on assets to be disposed of, if any, are based on the estimated proceeds to be received, less costs of disposal.