Employee Benefit Plans (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Contributions to Defined Contribution Plans	$ 90	$ 103
Discontinued Operations Defined Benefit Plan Recognized Net Gain Loss Due To Settlements And Curtailments		(5)
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Contributions to Defined Benefit Plans	84	29
Defined Benefit Plan, Service Cost	122	144
Defined Benefit Plan, Interest Cost	380	343
Defined Benefit Plan, Expected Return on Plan Assets	(554)	(527)
Defined Benefit Plan, Amortization of Transition Obligations, Assets and Prior Service Cost Credit	(2)	(9)
Defined Benefit Plan, Actuarial Net (Gains) Losses	107	240
Defined Benefit Plan, Recognized Net (Gain) Loss Due to Settlements and Curtailments	0	(3)
Defined Benefit Plan, Net Periodic Benefit Cost	53	188
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Service Cost	1	1
Defined Benefit Plan, Interest Cost	10	10
Defined Benefit Plan, Expected Return on Plan Assets	0	0
Defined Benefit Plan, Amortization of Transition Obligations, Assets and Prior Service Cost Credit	0	(3)
Defined Benefit Plan, Actuarial Net (Gains) Losses	(1)	(1)
Defined Benefit Plan, Recognized Net (Gain) Loss Due to Settlements and Curtailments	0	0
Defined Benefit Plan, Net Periodic Benefit Cost	10	7
United States Pension Plans Of US Entity Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Contributions to Defined Benefit Plans	$ 0	$ 0