Postretirement Benefits (Details 2) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Postretirement Benefits
Contributions to U.S. and non-U.S. pension plans	$ 105	$ 409	$ 340	$ 957
Expected full year contributions to U.S. and non-U.S. pension plans during the year	440		440
U.S. Pension Benefits
Components of net periodic benefit cost
Service cost	41	53	118	150
Interest cost	164	162	488	495
Expected return on plan assets	(200)	(193)	(598)	(574)
Amortization of:
Prior service cost / (credit)	5	6	15	20
Net actuarial loss / (gain)	112	96	338	271
Net periodic benefit cost, excluding curtailments, settlements and special termination benefits	122	124	361	362
Curtailments, settlements and special termination benefits		28		28
Total cost included in operating profit	122	152	361	390
Weighted-average assumptions used to determine net cost:
Discount rate (as a percent)			5.10%	5.60%
Expected return on plan assets (as a percent)			8.50%	8.50%
Rate of compensation increase (as a percent)			4.50%	4.50%
Non-U.S. Pension Benefits
Components of net periodic benefit cost
Service cost	28	23	83	69
Interest cost	45	42	132	124
Expected return on plan assets	(50)	(50)	(150)	(148)
Amortization of:
Prior service cost / (credit)	1	1	2	1
Net actuarial loss / (gain)	18	17	54	51
Net periodic benefit cost, excluding curtailments, settlements and special termination benefits	42	33	121	97
Curtailments, settlements and special termination benefits		9	9	17
Total cost included in operating profit	42	42	130	114
Weighted-average assumptions used to determine net cost:
Discount rate (as a percent)			4.60%	4.80%
Expected return on plan assets (as a percent)			7.10%	7.00%
Rate of compensation increase (as a percent)			4.20%	4.20%
Other Postretirement Benefits
Components of net periodic benefit cost
Service cost	21	17	62	50
Interest cost	64	62	190	184
Expected return on plan assets	(18)	(24)	(53)	(70)
Amortization of:
Transition obligation / (asset)	1		2	1
Prior service cost / (credit)	(14)	(14)	(41)	(41)
Net actuarial loss / (gain)	27	9	81	25
Net periodic benefit cost, excluding curtailments, settlements and special termination benefits	81	50	241	149
Total cost included in operating profit	$ 81	$ 50	$ 241	$ 149
Weighted-average assumptions used to determine net cost:
Discount rate (as a percent)			5.00%	5.60%
Expected return on plan assets (as a percent)			8.50%	8.50%
Rate of compensation increase (as a percent)			4.40%	4.40%