Retirement Benefits (Components Of Net Periodic Benefit Cost) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Pension Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 21	$ 24
Interest cost	49	40
Expected return on plan assets	(57)	(54)
Prior service cost (benefit)	0	(1)
Actuarial loss	12	22
Net periodic benefit cost	25	31
Postretirement Benefit Costs [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	5	6
Interest cost	13	12
Expected return on plan assets	(16)	(16)
Prior service cost (benefit)	(1)	(1)
Actuarial loss	(1)	2
Net periodic benefit cost	$ 0	$ 3