Fair Value Information (Fair Value Of Financial Instruments) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014		Dec. 31, 2013
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Cash and cash equivalents(a)	$ 1,165	[1]	$ 1,054	[1]
Time deposits(b)	102	[2]	222	[2]
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Short-term debt(d)	715		63
Long-term debt(e)	5,597		5,698
Estimated Fair Value, Fair Value Disclosure [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Cash and cash equivalents(a)	1,165	[1]	1,054	[1]
Time deposits(b)	102	[2]	222	[2]
Estimated Fair Value, Fair Value Disclosure [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Short-term debt(d)	715		63
Long-term debt(e)	6,278		6,271
Preferred securities [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Redeemable preferred securities of subsidiaries(c)	532		532
Preferred securities [Member] | Estimated Fair Value, Fair Value Disclosure [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Redeemable preferred securities of subsidiaries(c)	547	[3]	552
common securities [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Redeemable preferred securities of subsidiaries(c)	46	[4]	46
common securities [Member] | Estimated Fair Value, Fair Value Disclosure [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Redeemable preferred securities of subsidiaries(c)	$ 46	[4]	$ 46

[1] Cash equivalents are composed of certificates of deposit, time deposits and other interest-bearing investments with original maturity dates of 90 days or less. Cash equivalents are recorded at cost, which approximates fair value.

[2] Time deposits are composed of deposits with original maturities of more than 90 days but less than one year and instruments with original maturities of greater than one year, included in other current assets or other assets in the Consolidated Balance Sheet, as appropriate. Time deposits are recorded at cost, which approximates fair value.

[3] Redeemable preferred securities of subsidiaries are not traded in active markets. Accordingly, their fair values were calculated using a floating rate pricing model that compared the stated spread to the fair value spread to determine the price at which each of the financial instruments should trade. The model used the following inputs to calculate fair values: face value, current LIBOR rate, unobservable fair value credit spread, stated spread, maturity date and interest or dividend payment dates.

[4] The fair value of the redeemable common securities of subsidiary was based on various inputs, including an independent third-party appraisal, adjusted for current market conditions.