Employee Benefit Plans (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Net benefit cost	$ 2	$ 9	$ 1	$ 16
Pension Plan, Defined Benefit [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Net service cost	3	3	6	7
Interest cost	54	50	107	101
Expected return on plan assets	(55)	(51)	(111)	(103)
Prior service cost (benefit)	0	1	1	2
Actuarial loss	0	(5)	0	(15)
Defined Benefit Plan, Special Termination Benefits	0	11	0	24
Settlement			(2)	0
Net benefit cost	2	9	1	16
U.S. Pension Benefits [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Net service cost	0	0	0	0
Interest cost	34	31	66	62
Expected return on plan assets	(29)	(27)	(59)	(54)
Prior service cost (benefit)	0	0	0	0
Actuarial loss	0	(5)	0	(15)
Defined Benefit Plan, Special Termination Benefits	0	11	0	24
Settlement			0	0
Net benefit cost	5	10	7	17
International Pension Benefits [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Net service cost	3	3	6	7
Interest cost	20	19	41	39
Expected return on plan assets	(26)	(24)	(52)	(49)
Prior service cost (benefit)	0	1	1	2
Actuarial loss	0	0	0	0
Defined Benefit Plan, Special Termination Benefits	0	0	0	0
Settlement			(2)	0
Net benefit cost	(3)	(1)	(6)	(1)
Defined Benefit Plan, Contributions by Employer	16		31
Defined Benefit Plans, Estimated Future Employer Contributions in Current Fiscal Year			47
Defined Benefit Plan Estimated Total Employer Contributions in Current Fiscal Year	78		78
Executive Pension Plans [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Defined Benefit Plan, Contributions by Employer	18		18
Discretionary Pension Contributions [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Defined Benefit Plans, Estimated Future Employer Contributions in Current Fiscal Year			46
Discretionary Pension Contributions [Member] | International Pension Benefits [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Defined Benefit Plan Estimated Total Employer Contributions in Current Fiscal Year	$ 28		$ 28