Retirement Benefits - Expense (Details) (USD $)	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 130,000,000	$ 117,000,000
Interest cost	552,000,000	594,000,000
Expected return on assets	(718,000,000)	(757,000,000)
Defined Benefit Plan Amortization Categories [Abstract]
Prior service costs/(credits)	55,000,000	86,000,000
Defined Benefit Plan, Amortization of Gains (Losses)	(106,000,000)	(48,000,000)
Defined Benefit Plan Separation Programs and Other	7,000,000	(1,000,000)
(Gain)/Loss from curtailment and settlements
Net expense/(income)	132,000,000	87,000,000
Pension and Other Postretirement Benefit Contributions	500,000,000
Defined Benefit Plan, Estimated Future Employer Contributions in Next Fiscal Year	1,500,000,000
Non-U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	93,000,000	80,000,000
Interest cost	298,000,000	303,000,000
Expected return on assets	(334,000,000)	(348,000,000)
Defined Benefit Plan Amortization Categories [Abstract]
Prior service costs/(credits)	18,000,000	18,000,000
Defined Benefit Plan, Amortization of Gains (Losses)	(103,000,000)	(76,000,000)
Defined Benefit Plan Separation Programs and Other	34,000,000	12,000,000
(Gain)/Loss from curtailment and settlements	0
Net expense/(income)	212,000,000	141,000,000
Worldwide OPEB [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	17,000,000	15,000,000
Interest cost	72,000,000	82,000,000
Expected return on assets
Defined Benefit Plan Amortization Categories [Abstract]
Prior service costs/(credits)	(136,000,000)	(152,000,000)
Defined Benefit Plan, Amortization of Gains (Losses)	(32,000,000)	(29,000,000)
Defined Benefit Plan Separation Programs and Other	1,000,000
(Gain)/Loss from curtailment and settlements	(10,000,000)
Net expense/(income)	(24,000,000)	(26,000,000)
Pension and Other Postretirement Benefit Contributions	1,100,000,000
Pension and Other Postretirement Benefit Contributions Unfunded Plans	100,000,000
Defined Benefit Plan, Estimated Future Employer Contributions in Next Fiscal Year	2,300,000,000
Pension And Other Postretirement Expected Benefit Contributions Unfunded Plans	300,000,000
Pension and Other Postretirement Benefit Contributions and Expected Future Employer Contributions To Funded and Unfunded Plans	$ 3,800,000,000