Retirement Benefits (Net Periodic Pension Costs) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Defined Benefit Plan Disclosure [Line Items]
Net periodic pension cost	$ 5	$ 5	$ 5
U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Interest cost	349	344	344
Expected return on plan assets	(421)	(390)	(378)
Amortization of unrecognized net loss	260	189	151
Settlement/curtailment loss (gain)	0	8	2
Net periodic pension cost	188	151	119
Non-U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	10	17	24
Interest cost	75	72	84
Expected return on plan assets	(78)	(77)	(81)
Amortization of unrecognized net loss	22	17	19
Amortization of unrecognized prior service cost	(3)	(9)	(4)
Settlement/curtailment loss (gain)	0	(9)	(4)
Net periodic pension cost	$ 26	$ 11	$ 38