Financial Instruments (Tables)

9 Months Ended

Sep. 30, 2012

Fair Value Disclosures [Abstract]

Schedule of current and long-term debt, financing and capital lease

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)
September 30, 2012	$	21,304	$	16,166	$	6,617	$	—	$	22,783
December 31, 2011	$	20,274	$	12,567	$	5,732	$	—	$	18,299