Retirement Benefits (Details 3) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Amounts recorded in accumulated other comprehensive loss (Table Amounts)
Unamortized benefit plan costs	$ 3,000	$ 4,790
Pension Benefits
Amounts recorded in accumulated other comprehensive loss (Table Amounts)
Net actuarial loss	(5,291)	(8,057)
Prior service credit	423	481
Income tax benefits related to above items	1,928	3,003
Unamortized benefit plan costs	(2,940)	(4,573)
Medical and Life Benefits
Amounts recorded in accumulated other comprehensive loss (Table Amounts)
Net actuarial loss	(151)	(461)
Prior service credit	47	98
Income tax benefits related to above items	44	146
Unamortized benefit plan costs	$ (60)	$ (217)