Pension and Post-Retirement Benefits - Components of the Net Periodic Benefit Costs (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
United States
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	$ 10	$ 8	$ 7
Interest cost	7	7	8
Expected return on plan assets	(11)	(11)	(10)
Amortization	5	5	6
Settlement loss	0	0	7
Net periodic benefit cost	11	9	18
International
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	8	9	7
Interest cost	9	9	9
Expected return on plan assets	(10)	(10)	(9)
Amortization	4	2	1
Settlement loss	0	0	0
Net periodic benefit cost	11	10	8
Post-Retirement Medical Benefit Plans
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	1	1	1
Interest cost	2	3	3
Expected return on plan assets	0	0	0
Amortization	(1)	(1)	(1)
Settlement loss	0	0	0
Net periodic benefit cost	$ 2	$ 3	$ 3