Retirement Benefits (Components Of Net Periodic Benefit Cost) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 1	$ 104	$ 2	$ 208
Interest cost	163	191	326	382
Expected return on assets	(180)	(166)	(360)	(332)
Amortization of Prior service cost	7	3	14	7
Amortization of Unrecognized net (gain) loss	23	63	46	124
Net periodic benefit cost	14	195	28	389
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	15	0	30
Interest cost	13	38	26	76
Expected return on assets	(4)	(4)	(8)	(8)
Amortization of Prior service cost	(61)	(7)	(122)	(14)
Amortization of Unrecognized net (gain) loss	(2)	(2)	(4)	(4)
Net periodic benefit cost	$ (54)	$ 40	$ (108)	$ 80