Pension and Postretirement Benefit Plans (Components of net periodic benefit cost and other information) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
United States Qualified and Non-qualified Pension Benefits
Net periodic benefit cost (benefit)
Service cost	$ 64	$ 52	$ 127	$ 103
Interest cost	146	155	293	313
Expected return on plan assets	(248)	(232)	(496)	(464)
Amortization of transition (asset) obligation	0	0	0	0
Amortization of prior service cost (benefit)	1	3	3	6
Amortization of net actuarial (gain) loss	118	84	235	167
Net periodic benefit cost (benefit)	81	62	162	125
Settlements, curtailments, special termination benefits and other	0	0	26	0
Net periodic benefit cost (benefit) after settlements, curtailments, special termination benefits and other	81	62	188	125
International Qualified and Non-qualified Pension Benefits
Net periodic benefit cost (benefit)
Service cost	31	28	62	56
Interest cost	62	62	123	124
Expected return on plan assets	(73)	(69)	(146)	(139)
Amortization of transition (asset) obligation	0	0	(1)	0
Amortization of prior service cost (benefit)	(5)	(4)	(9)	(7)
Amortization of net actuarial (gain) loss	30	28	60	56
Net periodic benefit cost (benefit)	45	45	89	90
Settlements, curtailments, special termination benefits and other	0	0	0	0
Net periodic benefit cost (benefit) after settlements, curtailments, special termination benefits and other	45	45	89	90
Postretirement Benefits
Net periodic benefit cost (benefit)
Service cost	20	15	39	30
Interest cost	21	23	43	46
Expected return on plan assets	(22)	(20)	(43)	(39)
Amortization of transition (asset) obligation	0	0	0	0
Amortization of prior service cost (benefit)	(18)	(18)	(36)	(36)
Amortization of net actuarial (gain) loss	28	26	55	52
Net periodic benefit cost (benefit)	29	26	58	53
Settlements, curtailments, special termination benefits and other	0	0	0	0
Net periodic benefit cost (benefit) after settlements, curtailments, special termination benefits and other	$ 29	$ 26	$ 58	$ 53