Pension and Postretirement Benefit Plans (Components of net periodic benefit cost and other information) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
United States Qualified and Non-qualified Pension Benefits
Net periodic benefit cost (benefit)
Service cost	$ 64	$ 51	$ 191	$ 154
Interest cost	147	157	440	470
Expected return on plan assets	(248)	(231)	(744)	(695)
Amortization of transition (asset) obligation	0	0	0	0
Amortization of prior service cost (benefit)	1	2	4	8
Amortization of net actuarial (gain) loss	117	83	352	250
Net periodic benefit cost (benefit)	81	62	243	187
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	269	187
International Qualified and Non-qualified Pension Benefits
Net periodic benefit cost (benefit)
Service cost	31	27	93	83
Interest cost	61	62	184	186
Expected return on plan assets	(73)	(70)	(219)	(209)
Amortization of transition (asset) obligation	0	0	(1)	0
Amortization of prior service cost (benefit)	(4)	(3)	(13)	(10)
Amortization of net actuarial (gain) loss	30	28	90	84
Net periodic benefit cost (benefit)	45	44	134	134
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	44	134	134
Postretirement Benefits
Net periodic benefit cost (benefit)
Service cost	19	16	58	46
Interest cost	22	23	65	69
Expected return on plan assets	(21)	(20)	(64)	(59)
Amortization of transition (asset) obligation	0	0	0	0
Amortization of prior service cost (benefit)	(18)	(18)	(54)	(54)
Amortization of net actuarial (gain) loss	27	25	82	77
Net periodic benefit cost (benefit)	29	26	87	79
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	$ 87	$ 79