Pension, Other Postretirement Benefits (OPEB) And Savings Plans (Fair Value Measurements And The Levels Of Inputs Used In Determining Fair Values) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	$ 4,042		$ 3,750
Temporary Investment Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	32	[1]	118	[1]
Common Stocks Commingled - US [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	1,653	[2]	1,568	[2]
Common Stocks Commingled - International [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	603	[2]	696	[2]
Common Stocks Other [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	356		352	[2]
Commingled Bonds - US [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets			8	[3]
Government (US & Foreign) Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	662	[3]	378	[3]
Other Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	663	[3]	544	[3]
Pooled Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	36	[4]	48	[4]
Private Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	37	[5]	38	[5]
Quoted Market Prices For Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	2,612		2,616
Quoted Market Prices For Identical Assets (Level 1) [Member] | Temporary Investment Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	[1]	0	[1]
Quoted Market Prices For Identical Assets (Level 1) [Member] | Common Stocks Commingled - US [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	1,653	[2]	1,568	[2]
Quoted Market Prices For Identical Assets (Level 1) [Member] | Common Stocks Commingled - International [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	603	[2]	696	[2]
Quoted Market Prices For Identical Assets (Level 1) [Member] | Common Stocks Other [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	356		352	[2]
Quoted Market Prices For Identical Assets (Level 1) [Member] | Commingled Bonds - US [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets			0	[3]
Quoted Market Prices For Identical Assets (Level 1) [Member] | Government (US & Foreign) Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	[3]	0	[3]
Quoted Market Prices For Identical Assets (Level 1) [Member] | Other Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	[3]	0	[3]
Quoted Market Prices For Identical Assets (Level 1) [Member] | Pooled Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	[4]	0	[4]
Quoted Market Prices For Identical Assets (Level 1) [Member] | Private Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	[5]	0	[5]
Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	1,357		1,017
Significant Other Observable Inputs (Level 2) [Member] | Temporary Investment Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	32	[1]	95	[1]
Significant Other Observable Inputs (Level 2) [Member] | Common Stocks Commingled - US [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	[2]	0	[2]
Significant Other Observable Inputs (Level 2) [Member] | Common Stocks Commingled - International [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	[2]	0	[2]
Significant Other Observable Inputs (Level 2) [Member] | Common Stocks Other [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0		0	[2]
Significant Other Observable Inputs (Level 2) [Member] | Commingled Bonds - US [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets			0	[3]
Significant Other Observable Inputs (Level 2) [Member] | Government (US & Foreign) Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	662	[3]	378	[3]
Significant Other Observable Inputs (Level 2) [Member] | Other Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	663	[3]	544	[3]
Significant Other Observable Inputs (Level 2) [Member] | Pooled Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	[4]	0	[4]
Significant Other Observable Inputs (Level 2) [Member] | Private Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	[5]	0	[5]
Pension And OPEB Plans Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	73		117
Pension And OPEB Plans Level 3 [Member] | Temporary Investment Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	[1]	23	[1]	53
Pension And OPEB Plans Level 3 [Member] | Common Stocks Commingled - US [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	[2]	0	[2]
Pension And OPEB Plans Level 3 [Member] | Common Stocks Commingled - International [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	[2]	0	[2]
Pension And OPEB Plans Level 3 [Member] | Common Stocks Other [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0		0	[2]
Pension And OPEB Plans Level 3 [Member] | Commingled Bonds - US [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0		8	[3]	17
Pension And OPEB Plans Level 3 [Member] | Government (US & Foreign) Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	[3]	0	[3]
Pension And OPEB Plans Level 3 [Member] | Other Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	[3]	0	[3]
Pension And OPEB Plans Level 3 [Member] | Pooled Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	36	[4]	48	[4]	102
Pension And OPEB Plans Level 3 [Member] | Private Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	$ 37	[5]	$ 38	[5]	$ 37

[1] Certain temporary investment funds are valued using inputs such as time-to-maturity, coupon rate, quality rating and current yield (primarily Level 2), whereas certain other commingled temporary investment funds are measured with significant unobservable inputs and assumptions (primarily Level 3).

[2] Wherever possible, fair values of equity investments in stocks and in commingled funds are derived from quoted market prices as substantially all of these instruments have active markets (primarily Level 1). Most investments in stocks are priced utilizing the principal market close price or in some cases midpoint, bid or ask price.

[3] Investments in fixed income securities including bond funds are priced using an evaluated pricing approach or the most recent exchange or quoted bid (primarily Level 2). Certain investments in privately held commingled bond funds are valued using broker quotations or using inputs that are not market observable or can not be derived principally from or corroborated by observable market data (primarily Level 3).

[4] The fair value of real estate investments is based on the annual independent appraisals. The investments are also valued internally every quarter by the investment managers based on significant changes in property operations and market conditions (primarily Level 3).

[5] 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).