Pension, Other Postretirement Benefits and Savings Plans Change in benefit obligation and plan assets (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
United States Postretirement Benefit Plans of US Entity, Defined Benefit [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Funded Status of Plan	$ (322)	$ (353)
United States Pension Plans of US Entity, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	41	39	34
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Loss, Net Prior Service Cost (Credit), before Tax	101	124
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Loss, Net Gains (Losses), before Tax	2,900	2,314
Interest cost	(283)	(296)	(314)
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance	3,714
Ending balance	3,523	3,714
Defined Benefit Plan, Funded Status of Plan	(2,452)	(1,927)
Gross amount recognized - AOCL	3,001	2,438
Deferred income taxes - AOCL	(125)	(125)
Minority shareholders' equity	(59)	(48)
Net amount recognized	2,817	2,265
Foreign Pension Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	32	25	26
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Loss, Net Prior Service Cost (Credit), before Tax	8	11
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Loss, Net Gains (Losses), before Tax	844	840
Interest cost	(150)	(145)	(142)
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance	2,074
Ending balance	2,091	2,074
Defined Benefit Plan, Funded Status of Plan	(645)	(622)
Gross amount recognized - AOCL	852	851
Deferred income taxes - AOCL	(106)	(93)
Minority shareholders' equity	(111)	(128)
Net amount recognized	635	630
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	6	5	6
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Loss, Net Prior Service Cost (Credit), before Tax	(204)	(241)
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Loss, Net Gains (Losses), before Tax	185	180
Interest cost	(30)	(33)	(32)
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Funded Status of Plan	(576)	(597)
Gross amount recognized - AOCL	(19)	(61)
Deferred income taxes - AOCL	(6)	(2)
Minority shareholders' equity	3	3
Net amount recognized	(22)	(60)
Foreign Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Funded Status of Plan	(254)	(244)
Change in Benefit Obligation [Member] | United States Pension Plans of US Entity, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plans Newly Adopted Plans, Benefit Obligation	0	(2)
Service cost	41	(39)
Beginning balance	(5,641)	(5,343)
Interest cost	283	296
Plan amendments	0	0
Actuarial loss	(452)	(336)
Participant contributions	0	0
Defined Benefit Plan, Curtailments/Settlements	27	8
Termination benefits	0	(43)
Defined Benefit Plan, Divestitures, Benefit Obligation	0	0
Foreign currency translation	0	0
Benefit payments	415	410
Ending balance	(5,975)	(5,641)
Change in Benefit Obligation [Member] | Foreign Pension Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plans Newly Adopted Plans, Benefit Obligation	0	0
Service cost	(32)	(25)
Beginning balance	(2,696)	(2,715)
Interest cost	150	145
Plan amendments	0	(2)
Actuarial loss	(84)	(42)
Participant contributions	(2)	(3)
Defined Benefit Plan, Curtailments/Settlements	16	35
Termination benefits	(1)	0
Defined Benefit Plan, Divestitures, Benefit Obligation	5	0
Foreign currency translation	53	41
Benefit payments	155	160
Ending balance	(2,736)	(2,696)
Change in Benefit Obligation [Member] | Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plans Newly Adopted Plans, Benefit Obligation	0	0
Service cost	(6)	(5)
Beginning balance	(604)	(557)
Interest cost	30	33
Plan amendments	0	0
Actuarial loss	(17)	(49)
Participant contributions	(34)	(28)
Defined Benefit Plan, Curtailments/Settlements	0	(8)
Termination benefits	0	0
Defined Benefit Plan, Divestitures, Benefit Obligation	1	0
Foreign currency translation	15	(14)
Benefit payments	93	90
Ending balance	(582)	(604)
Change In Plan Assets [Member] | United States Pension Plans of US Entity, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Newly adopted plans	0	2
Participant contributions	0	0
Benefit payments	(415)	(410)
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance	3,714	3,412
Actual return on plan assets	23	473
Company contributions to plan assets	193	219
Cash funding of direct participant payments	35	19
Settlements	(27)	(1)
Divestitures	0	0
Foreign currency translation	0	0
Ending balance	3,523	3,714
Change In Plan Assets [Member] | Foreign Pension Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Newly adopted plans	0	0
Participant contributions	2	3
Benefit payments	(155)	(160)
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance	2,074	1,931
Actual return on plan assets	155	176
Company contributions to plan assets	40	142
Cash funding of direct participant payments	26	25
Settlements	(15)	(33)
Divestitures	(1)	0
Foreign currency translation	(35)	(10)
Ending balance	2,091	2,074
Change In Plan Assets [Member] | Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Newly adopted plans	0	0
Participant contributions	34	28
Benefit payments	(93)	(90)
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance	7	6
Actual return on plan assets	1	0
Company contributions to plan assets	3	2
Cash funding of direct participant payments	56	61
Settlements	0	0
Divestitures	(1)	0
Foreign currency translation	(1)	0
Ending balance	$ 6	$ 7