Employee Benefit Plans (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
U.S. [Member]
Change in Benefit Obligation
Benefit obligation at January 1	$ 13,654	$ 12,165
Service cost	495	452	374
Interest cost	471	435	463
Plan participants contributions	0	0
Plan amendments	(78)	94
Actuarial loss (gain)	(1,398)	1,322
Foreign currency exchange rate changes	0	0
Benefits paid	(1,064)	(763)
Divestitures	0	(51)
Benefit obligation at December 31	12,080	13,654	12,165
Change in Plan Assets
Fair value of plan assets at January	9,909	8,720
Actual return on plan assets	1,546	1,149
Foreign currency exchange rate changes	0	0
Employer Contributions	819	844
Plan participants contributions	0	0
Benefits paid	(1,064)	(763)
Divestitures	0	(41)
Fair value of plan assets at December 31	11,210	9,909	8,720
Funded Status at December 31	(870)	(3,745)
International [Member]
Change in Benefit Obligation
Benefit obligation at January 1	6,287	5,519
Service cost	197	181	174
Interest cost	314	320	325
Plan participants contributions	8	7
Plan amendments	18	37
Actuarial loss (gain)	(206)	417
Foreign currency exchange rate changes	(187)	114
Benefits paid	(336)	(308)
Divestitures	0	0
Benefit obligation at December 31	6,095	6,287	5,519
Change in Plan Assets
Fair value of plan assets at January	4,125	3,577
Actual return on plan assets	375	375
Foreign currency exchange rate changes	(21)	90
Employer Contributions	392	384
Plan participants contributions	8	7
Benefits paid	(336)	(308)
Divestitures	0	0
Fair value of plan assets at December 31	4,543	4,125	3,577
Funded Status at December 31	(1,552)	(2,162)
Other Benefits [Member]
Change in Benefit Obligation
Benefit obligation at January 1	3,787	3,765
Service cost	66	61	58
Interest cost	149	153	180
Plan participants contributions	154	151
Plan amendments	0	11
Actuarial loss (gain)	(636)	44
Foreign currency exchange rate changes	(23)	1
Benefits paid	(359)	(350)
Divestitures	0	(49)
Benefit obligation at December 31	3,138	3,787	3,765
Change in Plan Assets
Fair value of plan assets at January	0	0
Actual return on plan assets	0	0
Foreign currency exchange rate changes	0	0
Employer Contributions	205	199
Plan participants contributions	154	151
Benefits paid	(359)	(350)
Divestitures	0	0
Fair value of plan assets at December 31	0	0	0
Funded Status at December 31	$ (3,138)	$ (3,787)