Defined Benefit Postretirement Plans (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Pension and Other Postretirement Benefit Contributions [Abstract]
Pension Contributions					$ 50
Defined Benefit Plan, Estimated Future Employer Contributions in Current Fiscal Year					17
Defined Benefit Plan, Benefits Paid					19
Other Postretirement Benefits Payments					12
United States and Foreign Pension Plans Defined Benefit [Member]
Defined Benefit Plan Net Periodic Benefit Cost [Line Items]
Service cost	14		12		42		37
Interest cost	16		16		47		48
Expected return on plan assets	(17)		(14)		(50)		(46)
Amortization:
- prior service cost (credit)	2		2		5		6
-actuarial loss (gain)	9		12		38		37
Net settlement loss	15	[1]	34	[1]	32	[1]	34	[1]
Net periodic benefit cost	39		62		114		116
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, before Tax	24		(103)		163		(103)
Other Postretirement Benefit Plans Defined Benefit [Member]
Defined Benefit Plan Net Periodic Benefit Cost [Line Items]
Service cost	1		1		3		3
Interest cost	3		4		9		11
Expected return on plan assets	0		0		0		0
Amortization:
- prior service cost (credit)	(2)		(2)		(5)		(5)
-actuarial loss (gain)	0		0		0		0
Net settlement loss	0		0		0		0
Net periodic benefit cost	$ 2		$ 3		$ 7		$ 9

[1] (a) Settlements are recognized as they occur, once it is probable that lump sum payments from a plan for a given year will exceed the plan's total service and interest cost for that year. Such settlements were recorded for our U.S. plans in the second and third quarters of 2013 and the third quarter of 2012.