Retirement Benefits (Components Of Net Periodic Benefit Cost) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 1	$ 104	$ 3	$ 312
Interest cost	164	191	490	573
Expected return on assets	(180)	(166)	(540)	(498)
Amortization of Prior service cost	7	3	21	10
Amortization of Unrecognized net (gain) loss	23	63	69	187
Net periodic benefit cost	15	195	43	584
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	15	0	45
Interest cost	13	38	39	114
Expected return on assets	(4)	(4)	(12)	(12)
Amortization of Prior service cost	(61)	(7)	(183)	(21)
Amortization of Unrecognized net (gain) loss	(2)	(2)	(6)	(6)
Net periodic benefit cost	$ (54)	$ 40	$ (162)	$ 120