Retirement Benefits (Details 1) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Pension Benefits
Components of Net Periodic Benefit Cost (Table Amounts) [Abstract]
Service cost	$ 516	$ 522	$ 520
Interest cost	1,117	1,184	1,223
Expected return on plan assets	(1,809)	(1,708)	(1,690)
Amortization of:
Prior service (credit) cost	(58)	(58)	23
Net loss from previous years	608	427	162
Other	0	7	0
Net periodic benefit cost	374	374	238
Medical and Life Benefits
Components of Net Periodic Benefit Cost (Table Amounts) [Abstract]
Service cost	36	34	32
Interest cost	96	109	114
Expected return on plan assets	(75)	(68)	(62)
Amortization of:
Prior service (credit) cost	(51)	(51)	(51)
Net loss from previous years	30	21	17
Other	0	0	(6)
Net periodic benefit cost	$ 36	$ 45	$ 44