Pension and Post-Retirement Benefits - Rate Assumptions Associated with the Pension and Post-Retirement Medical Benefit Plans to Determine Benefit Obligations and Additional Year-End Information (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
United States
Defined Benefit Plan, Assumptions Used in Calculations [Abstract]
Discount rate	3.60%	4.35%
Compensation rate increase		3.55%
Measurement date	Dec-31	Dec-31
Additional year-end information
Accumulated benefit obligation	$ 178	$ 159
United States | Plans with accumulated benefit obligations in excess of plan assets:
Additional year-end information
Projected benefit obligation	178	170
Accumulated benefit obligation	178	159
Fair value of plan assets	158	138
United States | Plans with projected benefit obligations in excess of plan assets:
Additional year-end information
Projected benefit obligation	178	170
Fair value of plan assets	158	138
International
Defined Benefit Plan, Assumptions Used in Calculations [Abstract]
Discount rate	2.96%	3.52%
Compensation rate increase	2.59%	2.95%
Measurement date	Dec-31	Dec-31
Additional year-end information
Accumulated benefit obligation	268	227
International | Plans with accumulated benefit obligations in excess of plan assets:
Additional year-end information
Projected benefit obligation	206	260
Accumulated benefit obligation	183	227
Fair value of plan assets	140	198
International | Plans with projected benefit obligations in excess of plan assets:
Additional year-end information
Projected benefit obligation	299	260
Fair value of plan assets	228	198
Post-Retirement Medical Benefit Plans
Defined Benefit Plan, Assumptions Used in Calculations [Abstract]
Discount rate	3.90%	4.50%
Measurement date	Dec-31	Dec-31
Post-Retirement Medical Benefit Plans | Plans with projected benefit obligations in excess of plan assets:
Additional year-end information
Projected benefit obligation	47	52
Fair value of plan assets	$ 0	$ 0