Pension Plans, Postretirement and Other Employee Benefits (Details 8) (United States Postretirement Benefit Plans of US Entity, Defined Benefit [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
United States Postretirement Benefit Plans of US Entity, Defined Benefit [Member]
Amounts to be reflected as component of net periodic benefit cost in 2012
Net actuarial loss expected in 2012	$ 5
prior service credit expected in 2012	(6)
Total expected amounts that will be amortized from accumulated other comprehensive income in 2012	(1)
Estimated postretirement benefit payments
2012	9
2013	10
2014	10
2015	10
2016	10
2017-2021	48
Estimated subsidies under Medicare Prescription Drug, Improvement and Modernization Act
2012	1
2013	1
2014	1
2015	1
2016	1
2017-2021	$ 4
Weighted average assumptions used to determine benefit obligations
Discount rate	4.80%	5.60%
Rate of compensation increase	0.00%	0.00%
Weighted average assumptions used to determine net periodic benefit cost
Discount rate	5.60%	6.10%	6.20%
Rate of compensation increase			4.00%