Postretirement Benefit Plans (Details) (USD $) In Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Net periodic benefit cost
Service cost	$ 34	$ 33	$ 69	$ 66
Interest cost	92	94	185	187
Expected return on plan assets	115	115	230	230
Amortization of net actuarial loss	(31)	(24)	(62)	(48)
Amortization of prior service cost	1	0	1	1
Net periodic benefit cost (income)	43	36	87	72
U.S. Pension Plans [Member]
Net periodic benefit cost
Service cost	29	27	58	54
Interest cost	74	77	149	153
Expected return on plan assets	102	104	205	207
Amortization of net actuarial loss	(27)	(20)	(54)	(41)
Amortization of prior service cost	1	1	2	2
Net periodic benefit cost (income)	29	21	58	43
International Pension Plan [Member]
Net periodic benefit cost
Service cost	4	4	8	8
Interest cost	8	7	16	14
Expected return on plan assets	7	6	13	12
Amortization of net actuarial loss	(1)	(1)	(2)	(1)
Amortization of prior service cost	0	0	0	0
Net periodic benefit cost (income)	6	6	13	11
Total Pension Excluding Other Benefits (Member)
Net periodic benefit cost
Service cost	33	31	66	62
Interest cost	82	84	165	167
Expected return on plan assets	109	110	218	219
Amortization of net actuarial loss	(28)	(21)	(56)	(42)
Amortization of prior service cost	1	1	2	2
Net periodic benefit cost (income)	35	27	71	54
Other Benefits [Member]
Net periodic benefit cost
Service cost	1	2	3	4
Interest cost	10	10	20	20
Expected return on plan assets	6	5	12	11
Amortization of net actuarial loss	(3)	(3)	(6)	(6)
Amortization of prior service cost	0	(1)	(1)	(1)
Net periodic benefit cost (income)	$ 8	$ 9	$ 16	$ 18