Employee Benefit Plans (Details 2) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
United States Pension Plans of US Entity, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Service Cost	$ 0	$ 0	$ 0
Defined Benefit Plan, Interest Cost	861	930	969
Defined Benefit Plan, Expected Return on Plan Assets	(734)	(705)	(724)
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	0	0	0
Defined Benefit Plan, Amortization of Gains (Losses)	221	143	55
Defined Benefit Plan, Recognized Net (Gain) Loss Due to Settlements	6	0	0
Defined Benefit Plan, Other Costs	0	0	0
Defined Benefit Plan, Net Periodic Benefit Cost	354	368	300
Defined Contribution Plan, Cost Recognized	490	426	377
Defined Benefit Plan Cost Benefit	844	794	677
United States Postretirement Benefit Plans of US Entity, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Service Cost	49	56	52
Defined Benefit Plan, Interest Cost	143	164	180
Defined Benefit Plan, Expected Return on Plan Assets	(84)	(77)	(90)
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	(26)	(21)	(3)
Defined Benefit Plan, Amortization of Gains (Losses)	25	23	(11)
Defined Benefit Plan, Recognized Net (Gain) Loss Due to Settlements	0	0	0
Defined Benefit Plan, Other Costs	0	116	0
Defined Benefit Plan, Net Periodic Benefit Cost	107	261	128
Defined Contribution Plan, Cost Recognized	0	0	0
Defined Benefit Plan Cost Benefit	$ 107	$ 261	$ 128