Supplemental Cash Flow Information (Tables)

3 Months Ended

Mar. 31, 2013

Table Text Block [Abstract]

Supplemental Cash Flow Table

		Three Months Ended
		March 31,
millions		2013		2012
Cash paid (received)
	Interest	$	251	$	265
	Income taxes	$	28	$	(70)
Non-cash investing activities
	Fair value of properties and equipment received in non-cash exchange transactions	$	13	$	—