Employee Benefit Plans (Components Of Net Periodic Benefit Cost) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Other Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 45		$ 53		$ 49
Interest cost	76		74		83
Expected return on plan assets	(103)		(79)		(77)
Amortization of transition obligation	0		0		24
Amortization of prior service cost	23		23		25
Amortization of net actuarial loss	2		6		6
Net periodic benefit cost	43		77		110
Pension Plans Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	383		468		396
Interest cost	695		627		658
Expected return on plan assets	(807)		(650)		(598)
Amortization of prior service cost	20		20		20
Amortization of net actuarial loss	2		111		123
Net periodic benefit cost	293		576		599
Less: transfer to regulatory account	42	[1]	(238)	[1]	(301)	[1]
Total	$ 335		$ 338		$ 298

[1] The Utility recorded these amounts to a regulatory account as they are probable of recovery from customers in future rates.