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		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Defined Benefit Plans [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans
Service cost	$ 12	$ 13	$ 36	$ 40
Interest cost	70	63	209	191
Expected return on plan assets	(83)	(82)	(249)	(246)
Recognized net actuarial loss	25	28	75	91
Curtailment	0	(1)	0	(30)
Other	1	2	6	(1)
Net periodic benefit cost	25	23	77	45
Other Postretirement Benefit Plans [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans
Service cost	3	4	9	12
Interest cost	9	9	27	25
Expected return on plan assets	0	0	0	0
Recognized net actuarial loss	0	2	0	2
Curtailment	0	0	0	0
Other	0	0	0	0
Net periodic benefit cost	$ 12	$ 15	$ 36	$ 39