This excerpt taken from the MRO 10-K filed Mar 10, 2005.
18. Fair Value of Financial Instruments
Fair value of the financial instruments disclosed herein is not necessarily representative of the amount that could be realized or settled, nor does the fair value amount consider the tax consequences of realization or settlement. The following table summarizes financial instruments, excluding derivative financial instruments disclosed in Note 17, by individual balance sheet account. Marathon's financial instruments at December 31, 2004 and 2003 were:
Fair value of financial instruments classified as current assets or liabilities approximates carrying value due to the short-term maturity of the instruments. Fair value of investments and long-term receivables was based on discounted cash flows or other specific instrument analysis. Fair value of long-term debt instruments was based on market prices where available or current borrowing rates available for financings with similar terms and maturities. Fair value of the receivables from United States Steel was estimated using market prices for United States Steel debt assuming the industrial revenue bonds are redeemed on or before the tenth anniversary of the Separation per the Financial Matters Agreement.