Notes to Consolidated Financial Statements Costs and estimated earnings on uncompleted contracts and related amounts billed as of December 31, 2000 and 1999 were as follows (in thousands): Inventories, which consist primarily of construction materials, are stated at the lower of cost or market. Cost is determined principally using average cost. Investments, notes and other long-term receivables at December 31, 2000 were $10.4 million compared to $8.2 million at December 31, 1999, and primarily consist of investments in joint ventures accounted for using the equity method of accounting. Property, plant and equipment is stated at cost. Depreciation is recorded principally using the straight-line method over estimated useful lives ranging from 3 to 40 years. Property, plant and equipment in the accompanying Consolidated Balance Sheets consisted of the following amounts as of December 31, 2000 and 1999 (in thousands): Such amounts were included in the accompanying Consolidated Balance Sheets at December 31, 2000 and 1999 under the following captions (in thousands): As of December 31, 2000, costs and estimated earnings in excess of billings on uncompleted contracts included unbilled  revenues for unapproved change orders of approximately $19.7 million and claims of approximately $12.8 million. In addition, accounts receivable as of December 31, 2000 includes claims  and contractually billed amounts related to such contracts of approximately $20.1 million. Claims and related amounts  included in accounts receivable aggregated approximately $28.3 million as of December 31, 1999. Generally, contractually billed amounts will not be paid by the customer to EMCOR until final resolution of related claims. Goodwill at December 31, 2000 and 1999, was approximately $67.6 million and $68.0 million, respectively, and reflects the  excess of cost over fair market value of net identifiable assets of companies acquired in purchase transactions. Goodwill is being amortized using the straight-line method over periods ranging from 5 to 20 years. In accordance with industry practice, EMCOR classifies as  current all assets and liabilities related to the performance of long-term contracts. The contracting cycle for certain long-term contracts may extend beyond one year and, accordingly, collection or payment of amounts related to these contracts may extend beyond one year. Accounts receivable at December 31, 2000 and 1999 included $160.9 million and $128.7 million, respectively, of retainage billed under terms of the contracts. EMCOR estimates that approximately 75% of retainage recorded at December 31, 2000 will be collected during 2001. At the end of each quarter, EMCOR reviews events and changes in circumstances to determine whether the recoverability of the carrying value of goodwill should be reassessed. Should events or circumstances indicate that the carrying value may not  be recoverable based on undiscounted future cash flows, an  impairment loss measured by the difference between the  discounted future cash flows (or another acceptable method for determining fair value) and the carrying value of goodwill would be recognized by EMCOR. Through December 31, 2000, no  adjustment for the impairment of goodwill carrying value has  been required. For purposes of the consolidated financial statements, EMCOR considers all highly liquid instruments with original maturities of three months or less to be cash equivalents. EMCOR maintains a centralized cash management program whereby its excess cash  balances are invested in high quality, short-term money market instruments which are considered cash equivalents. At times, cash balances in EMCOR’s bank accounts may exceed federally insured limits. EMCOR’s insurance liability is determined actuarially based  on claims filed and an estimate of claims incurred but not yet  reported. At December 31, 2000 and 1999, the estimated  current portion of the discounted insurance liability was  included in “Other accrued expenses and liabilities” in the  accompanying Consolidated Balance Sheets. The non-current  portion of the discounted insurance liability was included in “Other long-term obligations”. EMCOR, 2000 Annual Report 28 Insurance Reserves  Cash and Cash Equivalents Classification of Contract Amounts Goodwill Property, Plant and Equipment Investments, Notes and Other Long-Term Receivables Inventories 2000 1999 Costs and estimated earnings in excess of billings on uncompleted contracts $ 158,073 $ 142,000 Billings in excess of costs and estimated earnings on uncompleted contracts (314,929) (216,152) $ (156,856) $ (74,152) 2000 1999 Machinery and equipment $ 45,042 $ 42,233 Furniture and fixtures 16,905 13,658 Land, buildings and leasehold improvements 24,740 21,449 86,687 77,340 Accumulated depreciation and amortization (47,728) (40,831) $ 38,959 $ 36,509 2000 1999 Costs incurred on uncompleted contracts $ 5,552,430 $ 4,906,654 Estimated earnings 403,416 410,755 5,955,846 5,317,409 Less: billings to date 6,112,702 5,391,561 $ (156,856) $ (74,152)