Accumulated Other Comprehensive Loss (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012	Dec. 31, 2011
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated Other Comprehensive Loss, Pension and Other Benefit Liabilities	$ (5,096)	$ (3,769)	$ (5,147)	$ (3,899)
Accumulated Other Comprehensive Loss, Derivative Contracts	(185)	(372)	(286)	(413)
Accumulated Other Comprehensive Loss, Deferred Tax Impact	(3,050)	(2,349)	(3,144)	(2,454)
Accumulated Other Comprehensive Loss	(8,331)	(6,490)	(8,577)	(6,766)
Changes in value, Pension and Other Benefit Liabilities	(29)	127
Changes in value, Derivative contracts	207	72
Changes in value, Deferred tax impact	0	0
Changes In value, Accumulated Other Comprehensive Loss	178	199
Actuarial losses, Pension and Other Benefits Liabilities related adjustments from AOCI to earnings	113	78
Foreign currency exchange contracts, Derivatives Contracts related adjustments from AOCI to earnings	(45)	(1)
Deferred tax impact, reclassification adjustments from AOCI to earnings	0	0
Accumulated Other Comprehensive Loss, Reclassifications into earnings	68	77
Tax effect, Pension and other benefit liabilities	(33)	(75)
Tax effect, Derivative contracts	(61)	(30)
Tax effect, Deferred tax impact	94	105
Tax effect, Other Comprehensive Loss	$ 0	$ 0