Employee Benefit Plans (Details 4) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Changes Recognized in Other Comprehensive Income
Prior service cost during period	$ 27	$ 12	$ 34
Amortization of prior service credits (costs)	(26)	(61)	(65)
U.S. [Member]
Net Periodic Benefit Cost
Service cost	374	337	266
Interest cost	463	486	481
Expected return on plan assets	(613)	(538)	(395)
Amortization of prior service (credits) costs	(8)	(8)	(7)
Recognized actuarial losses	310	318	298
Settlement losses	298	186	141
Total net periodic benefit cost	824	781	784
Changes Recognized in Other Comprehensive Income
Net actuarial loss during period	2,671	242	823
Amortization of actuarial loss	(608)	(504)	(439)
Prior service cost during period			1
Amortization of prior service credits (costs)	8	8	7
Total changes recognized in other comprehensive income	2,071	(254)	392
Recognized in Net Periodic Benefit Cost and Other Comprehensive Income	2,895	527	1,176
International [Member]
Net Periodic Benefit Cost
Service cost	174	153	128
Interest cost	325	307	292
Expected return on plan assets	(283)	(241)	(203)
Amortization of prior service (credits) costs	19	22	23
Recognized actuarial losses	101	98	108
Settlement losses		6	1
Curtailment losses (gains)	35
Total net periodic benefit cost	371	345	349
Changes Recognized in Other Comprehensive Income
Net actuarial loss during period	448	118	194
Amortization of actuarial loss	(101)	(104)	(109)
Prior service cost during period	27		13
Amortization of prior service credits (costs)	(54)	(22)	(23)
Total changes recognized in other comprehensive income	320	(8)	75
Recognized in Net Periodic Benefit Cost and Other Comprehensive Income	691	337	424
Other Benefits [Member]
Net Periodic Benefit Cost
Service cost	58	39	43
Interest cost	180	175	180
Expected return on plan assets	0	0	0
Amortization of prior service (credits) costs	(72)	(75)	(81)
Recognized actuarial losses	64	27	27
Settlement losses	0	0	0
Curtailment losses (gains)	(10)		(5)
Total net periodic benefit cost	220	166	164
Changes Recognized in Other Comprehensive Income
Net actuarial loss during period	131	497	82
Amortization of actuarial loss	(64)	(27)	(27)
Prior service cost during period		12	20
Amortization of prior service credits (costs)	72	75	81
Total changes recognized in other comprehensive income	139	557	156
Recognized in Net Periodic Benefit Cost and Other Comprehensive Income	$ 359	$ 723	$ 320