Pension Plans, Postretirement and Other Employee Benefits (Details 7) (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]
Component of net periodic postretirement benefit cost (income)
Service cost-benefits earned during the period	$ 1	$ 1	$ 1
Interest on accumulated postretirement benefit obligation	7	8	8
Net amortization:
Actuarial loss	4	4	5
Prior service cost (credit)	(6)	(6)	(6)
Net pension and postretirement costs	$ 6	$ 7	$ 8