Financial Instruments

6 Months Ended

Jun. 30, 2012

Fair Value Disclosures [Abstract]

Financial Instruments

Note 4. Financial Instruments

Cash and cash equivalents, accounts and notes receivable, and accounts payable are carried at cost, which approximates fair value. Our short-term investments (consisting primarily of time deposits, commercial paper, certificate of deposits, and Treasury securities), totaling $902 million and $150 million as of June 30, 2012 and December 31, 2011, respectively, are recorded at amortized cost, and the respective carrying amounts approximate fair value. The fair value of our marketable equity securities totaling $43 million as of both June 30, 2012 and December 31, 2011, is measured on a recurring basis using quoted prices in active markets.

The estimated fair value of current and long-term debt is determined based on quoted prices in active markets or by using other observable inputs that are derived principally from or corroborated by observable market data. The fair value of financing and capital lease obligations is estimated using a valuation model based on the lease terms of the obligations and market-based parameters such as bond interest rates. The following table presents carrying amounts and estimated fair values of our current and long-term debt, financing and capital lease obligations:

	Carrying amount		Estimated Fair Value Using Input Type
			Quoted prices in active markets		Observable		Unobservable		Total estimated fair value
	(in millions)
June 30, 2012	$	21,264	$	12,728	$	8,225	$	—	$	20,953
December 31, 2011	$	20,274	$	12,567	$	5,732	$	—	$	18,299