Principles Of Consolidation And Other Matters (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	Dec. 31, 2011
Equity method gains (losses)	$ 4	$ (4)	$ 24	$ 14
Equity method investments	100		100
Remaining capital commitment	67		67
Effective tax rate	29.80%	31.10%	30.00%	29.80%
Gross unrecognized tax benefits	176		176		143
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	108	102	108	102
Excluding Tax Benefit [Member]
Effective tax rate				31.40%
Minimum [Member] | Significant Change in Unrecognized Tax Benefits is Reasonably Possible Estimated Range of Change Upper Limit [Member]
Projection of unrecognized tax benefit in twelve months, lower bound	0		0
Maximum [Member] | Significant Change in Unrecognized Tax Benefits is Reasonably Possible Estimated Range of Change Upper Limit [Member]
Projection of unrecognized tax benefit in twelve months, upper bound	$ 50		$ 50