Employee Postretirement Benefits (Benefit Cost Information For Defined Benefit Plans And Other Postretirement Benefit Plans) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Defined Benefit Plans [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans
Service cost	$ 11	$ 14
Interest cost	68	64
Expected return on plan assets	(82)	(81)
Recognized net actuarial loss	24	34
Curtailment (see Note 3)	0	(26)
Other	5	(3)
Net periodic benefit cost	26	2
Other Postretirement Benefit Plans [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans
Service cost	4	4
Interest cost	9	8
Expected return on plan assets	0	0
Recognized net actuarial loss	0	0
Curtailment (see Note 3)	0	0
Other	0	0
Net periodic benefit cost	$ 13	$ 12