Employee Benefit Plans (Details 5) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Effects of change in the assumed health care cost-trend rates
Effect on total service and interest cost components, 1 Percent Increase	16
Effect on total service and interest cost components, 1 Percent Decrease	(13)
Effect on postretirement benefit obligation, 1 Percent Increase	165
Effect on postretirement benefit obligation, 1 Percent Decrease	(141)
U.S. [Member]
Assumptions used to determine benefit obligations:
Discount rate	3.60%	3.80%	4.80%
Rate of compensation increase	4.50%	4.50%	4.50%
Assumptions used to determine net periodic benefit cost:
Discount rate	3.80%	4.80%	5.30%
Expected return on plan assets	7.50%	7.80%	7.80%
Rate of compensation increase	4.50%	4.50%	4.50%
International [Member]
Assumptions used to determine benefit obligations:
Discount rate	5.20%	5.90%	6.50%
Rate of compensation increase	5.50%	5.70%	6.70%
Assumptions used to determine net periodic benefit cost:
Discount rate	5.90%	6.50%	6.80%
Expected return on plan assets	7.50%	7.80%	7.80%
Rate of compensation increase	5.70%	6.70%	6.30%
Other Benefits [Member]
Assumptions used to determine benefit obligations:
Discount rate	4.10%	4.20%	5.20%
Assumptions used to determine net periodic benefit cost:
Discount rate	4.20%	5.20%	5.90%