New And Significant Accounting Policies (Components Of Net Periodic Benefit Cost) (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost for benefits earned		$ 123	$ 92	$ 360	$ 287
Interest cost		168	175	505	521
Expected return on plan assets		(219)	(202)	(655)	(605)
Amortization of prior service cost		4	5	11	15
Amortization of net actuarial loss		1	1	7	2
Net periodic benefit cost		77	71	228	220
Less: transfer to regulatory account	[1]	8	13	26	31
Total		85	84	254	251
Other Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost for benefits earned		14	12	41	34
Interest cost		18	19	54	57
Expected return on plan assets		(28)	(25)	(84)	(77)
Amortization of prior service cost		4	6	14	17
Amortization of net actuarial loss		1	1	3	2
Net periodic benefit cost		9	13	28	33
Less: transfer to regulatory account	[1]	0	0	0	0
Total		$ 9	$ 13	$ 28	$ 33

[1] The Utility recorded these amounts to a regulatory account since they are probable of recovery from, or refund to, customers in futures rates.