Retirement Benefits - Expense (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 130,000,000	$ 116,000,000	$ 390,000,000	$ 350,000,000
Interest cost	552,000,000	594,000,000	1,656,000,000	1,782,000,000
Expected return on assets	(718,000,000)	(757,000,000)	(2,154,000,000)	(2,271,000,000)
Defined Benefit Plan Amortization Categories [Abstract]
Prior service costs/(credits)	55,000,000	86,000,000	165,000,000	257,000,000
(Gains)/Losses	106,000,000	49,000,000	318,000,000	145,000,000
Separation programs/other	(1,000,000)		4,000,000	(1,000,000)
(Gains)/Losses from curtailment and settlements
Net expense/(income)	124,000,000	88,000,000	379,000,000	262,000,000
Pension Plan Contributions [Abstract]
Pension and Other Postretirement Benefit Contributions			1,500,000,000
Defined Benefit Plan, Estimated Future Employer Contributions in Next Fiscal Year	500,000,000		500,000,000
Non-U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	92,000,000	83,000,000	278,000,000	247,000,000
Interest cost	293,000,000	312,000,000	889,000,000	929,000,000
Expected return on assets	(332,000,000)	(356,000,000)	(1,001,000,000)	(1,062,000,000)
Defined Benefit Plan Amortization Categories [Abstract]
Prior service costs/(credits)	18,000,000	18,000,000	54,000,000	54,000,000
(Gains)/Losses	102,000,000	75,000,000	308,000,000	228,000,000
Separation programs/other	9,000,000	80,000,000	54,000,000	140,000,000
(Gains)/Losses from curtailment and settlements	0		0	104,000,000
Net expense/(income)	182,000,000	212,000,000	582,000,000	640,000,000
Worldwide OPEB [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	17,000,000	16,000,000	51,000,000	47,000,000
Interest cost	72,000,000	83,000,000	216,000,000	248,000,000
Expected return on assets
Defined Benefit Plan Amortization Categories [Abstract]
Prior service costs/(credits)	(137,000,000)	(151,000,000)	(409,000,000)	(454,000,000)
(Gains)/Losses	33,000,000	28,000,000	97,000,000	85,000,000
Separation programs/other		8,000,000	1,000,000	9,000,000
(Gains)/Losses from curtailment and settlements		(23,000,000)	(10,000,000)	(23,000,000)
Net expense/(income)	(15,000,000)	(39,000,000)	(54,000,000)	(88,000,000)
Pension Plan Contributions [Abstract]
Pension and Other Postretirement Benefit Contributions			2,500,000,000
Pension and Other Postretirement Benefit Contributions Unfunded Plans			300,000,000
Defined Benefit Plan, Estimated Future Employer Contributions in Next Fiscal Year	900,000,000		900,000,000
Pension And Other Postretirement Expected Benefit Contributions Unfunded Plans	100,000,000		100,000,000
Pension and Other Postretirement Benefit Contributions and Expected Future Employer Contributions To Funded and Unfunded Plans	$ 3,800,000,000		$ 3,800,000,000