Pension, OPEB and Savings Plans (Reconciliations Of The Beginning And Ending Balances Of Pension And OPEB Plans' Level 3 Assets) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Assets at End of Year	$ 5,654		$ 5,435
Pension And OPEB Plans Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Assets at End of Year	25		25
Private Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Assets at End of Year	25	[1]	25	[1]
Private Equity [Member] | Pension And OPEB Plans Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Assets at Beginning of Year	25	[1]	31
Purchases/(Sales)	(5)		(11)
Transfer In/ (Out)	0		0
Actual Return on Asset Sales	3		11
Actual Return on Assets Still Held	2		(6)
Fair Value of Assets at End of Year	$ 25	[1]	$ 25	[1]

[1] Limited partnership interests in private equity funds are valued using significant unobservable inputs as there is little, if any, market activity. In addition, there may be transfer restrictions on private equity securities. The process for determining the fair value of such securities relied on commonly accepted valuation techniques, including the use of earnings multiples based on comparable public securities, industry-specific non-earnings-based multiples and discounted cash flow models. These inputs require significant management judgment or estimation (primarily Level 3).