Postretirement Benefit Plans (Details) (USD $) In Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Net periodic benefit cost:
Service cost	$ 37	$ 32	$ 106	$ 98
Interest cost	94	94	277	281
Expected return on plan assets	(115)	(115)	(344)	(345)
Amortization of net actuarial loss	32	23	94	71
Amortization of prior service cost	1	1	2	2
Net periodic benefit cost	49	35	135	107
Loss from curtailment/special termination benefits	5	0	5	0
Total net periodic benefit cost	54	35	140	107
Other changes in plan assets and benefit obligations recognized in other comprehensive income
Net loss (gain)	59	0	959	0
Prior service cost recognized from curtailment	(3)	0	(3)	0
Amortization of net actuarial loss	(32)	(23)	(94)	(71)
Amortization of prior service cost	(1)	(1)	(2)	(2)
Total change recognized in other comprehensive income	923	(24)	860	(73)
Total impact from net periodic benefit cost and changes in other comprehensive income	977	11	1,000	34
U.S. Pension Plans [Member]
Net periodic benefit cost:
Service cost	30	27	87	81
Interest cost	76	77	225	230
Expected return on plan assets	(102)	(104)	(307)	(311)
Amortization of net actuarial loss	28	20	82	61
Amortization of prior service cost	1	1	3	3
Net periodic benefit cost	33	21	90	64
Loss from curtailment/special termination benefits	5	0	5	0
Total net periodic benefit cost	38	21	95	64
Other changes in plan assets and benefit obligations recognized in other comprehensive income
Net loss (gain)	49	0	949	0
Prior service cost recognized from curtailment	(3)	0	(3)	0
Amortization of net actuarial loss	(28)	(20)	(82)	(61)
Amortization of prior service cost	(1)	(1)	(3)	(3)
Total change recognized in other comprehensive income	917	(21)	861	(64)
Total impact from net periodic benefit cost and changes in other comprehensive income	955	0	956	0
International Pension Plan [Member]
Net periodic benefit cost:
Service cost	6	4	14	12
Interest cost	8	7	24	21
Expected return on plan assets	(7)	(6)	(20)	(18)
Amortization of net actuarial loss	1	1	3	2
Amortization of prior service cost	0	0	0	0
Net periodic benefit cost	8	6	21	17
Loss from curtailment/special termination benefits	0	0	0	0
Total net periodic benefit cost	8	6	21	17
Other changes in plan assets and benefit obligations recognized in other comprehensive income
Net loss (gain)	10	0	10	0
Prior service cost recognized from curtailment	0	0	0	0
Amortization of net actuarial loss	(1)	(1)	(3)	(2)
Amortization of prior service cost	0	0	0	0
Total change recognized in other comprehensive income	9	(1)	7	(2)
Total impact from net periodic benefit cost and changes in other comprehensive income	17	5	28	15
Total Pension Excluding Other Benefits (Member)
Net periodic benefit cost:
Service cost	36	31	101	93
Interest cost	84	84	249	251
Expected return on plan assets	(109)	(110)	(327)	(329)
Amortization of net actuarial loss	29	21	85	63
Amortization of prior service cost	1	1	3	3
Net periodic benefit cost	41	27	111	81
Loss from curtailment/special termination benefits	5	0	5	0
Total net periodic benefit cost	46	27	116	81
Other changes in plan assets and benefit obligations recognized in other comprehensive income
Net loss (gain)	59	0	959	0
Prior service cost recognized from curtailment	(3)	0	(3)	0
Amortization of net actuarial loss	(29)	(21)	(85)	(63)
Amortization of prior service cost	(1)	(1)	(3)	(3)
Total change recognized in other comprehensive income	926	(22)	868	(66)
Total impact from net periodic benefit cost and changes in other comprehensive income	972	5	984	15
Other Benefits [Member]
Net periodic benefit cost:
Service cost	1	1	5	5
Interest cost	10	10	28	30
Expected return on plan assets	(6)	(5)	(17)	(16)
Amortization of net actuarial loss	3	2	9	8
Amortization of prior service cost	0	0	(1)	(1)
Net periodic benefit cost	8	8	24	26
Loss from curtailment/special termination benefits	0	0	0	0
Total net periodic benefit cost	8	8	24	26
Other changes in plan assets and benefit obligations recognized in other comprehensive income
Net loss (gain)	0	0	0	0
Prior service cost recognized from curtailment	0	0	0	0
Amortization of net actuarial loss	(3)	(2)	(9)	(8)
Amortization of prior service cost	0	0	1	1
Total change recognized in other comprehensive income	(3)	(2)	(8)	(7)
Total impact from net periodic benefit cost and changes in other comprehensive income	$ 5	$ 6	$ 16	$ 19