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		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Defined Benefit Plans [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans
Service cost	$ 13	$ 13	$ 24	$ 27
Interest cost	71	64	139	128
Expected return on plan assets	(84)	(83)	(166)	(164)
Recognized net actuarial loss	26	29	50	63
Curtailment (see Note 3)	0	(3)	0	(29)
Defined Benefit Plan, Other Costs			5	(3)
Net periodic benefit cost	26	20	52	22
Other Postretirement Benefit Plans [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans
Service cost	2	4	6	8
Interest cost	9	8	18	16
Expected return on plan assets	0	0	0	0
Recognized net actuarial loss	0	0	0	0
Curtailment (see Note 3)	0	0	0	0
Defined Benefit Plan, Other Costs			0	0
Net periodic benefit cost	$ 11	$ 12	$ 24	$ 24