Other Income and Expense (Details) (USD $) In Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Component Of Other Income [Line Items]
Total other income	$ 34	$ 68	$ 50	$ 77
Component Of Operating Other Cost And Expense [Line Items]
Total other expense	38	48	55	60
Gain On Extinguishment Of Liability [Member]
Component Of Other Income [Line Items]
Total other income	0	62	0	62
Other Income Net Of Tax And NCI		9
Gain on sale of assets
Component Of Other Income [Line Items]
Total other income	14	0	16	0
Other Income Other Member
Component Of Other Income [Line Items]
Total other income	20	6	34	15
Wind Transaction Costs [Member]
Component Of Operating Other Cost And Expense [Line Items]
Total other expense	0	22	0	22
Loss On Disposal Of Assets [Member]
Component Of Operating Other Cost And Expense [Line Items]
Total other expense	17	12	29	19
Other Member
Component Of Operating Other Cost And Expense [Line Items]
Total other expense	6	5	11	10
Loss On Extinguishment Of Debt [Member]
Component Of Operating Other Cost And Expense [Line Items]
Total other expense	$ 15	$ 9	$ 15	$ 9