Other Income (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Other Income Details [Abstract]
Rental income	$ 21	$ 19	$ 41	$ 39
Net gain on non-operating asset dispositions	11	4	12	5
Interest Income	0	1	1	2
Early extinguishment of debt	(2)	0	(2)	0
Non-operating environmental costs and other	(9)	2	(15)	(5)
Total	$ 21	$ 26	$ 37	$ 41