Annual report pursuant to Section 13 and 15(d)

Assets And Liabilities Measured At Fair Value (Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Details)

Assets And Liabilities Measured At Fair Value (Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Cash Equivalents, at Carrying Value	$ 2,316	$ 694
Realized and unrealized gains (losses) on financial instruments, net (note 5)	(351)	84	62
Available-for-sale securities	1,815	1,165
Debt	2,930	2,443
Quoted Prices In Active Markets For Identical Assets (Level 1)
Cash Equivalents, at Carrying Value	2,305	694
Available-for-sale securities	1,668	1,165
Debt	0	0
Significant Other Observable Inputs (Level 2)
Cash Equivalents, at Carrying Value	11	0
Available-for-sale securities	147	0
Debt	2,930	2,443
Non-Strategic Securities [Member]
Realized and unrealized gains (losses) on financial instruments, net (note 5)	470	55	202
Exchangeable Senior Debentures [Member]
Realized and unrealized gains (losses) on financial instruments, net (note 5)	(602)	(46)	(257)
Other Financial Instruments [Member]
Realized and unrealized gains (losses) on financial instruments, net (note 5)	$ (219)	$ 75	$ 117

- Definition

This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents Available-for-sale Securities which consist of all investments in certain debt and equity securities neither classified as trading or held-to-maturity securities. A debt security represents a creditor relationship with an enterprise. Debt securities include, among other items, US Treasury securities, US government securities, municipal securities, corporate bonds, convertible debt, commercial paper, and all securitized debt instruments. An equity security represents an ownership interest in an enterprise or the right to acquire or dispose of an ownership interest in an enterprise at fixed or determinable prices. Equity securities include, among other things, common stock, certain preferred stock, warrant rights, call options, and put options, but do not include convertible debt. An entity may opt to provide the reader with additional narrative text to better understand the nature of investments in debt and equity securities which are categorized as Available-for-sale.

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- Definition

Amount of short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

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- Definition

This item represents the net total realized and unrealized gain (loss) included in earnings for the period as a result of selling or holding marketable securities categorized as trading, available-for-sale, or held-to-maturity, including the unrealized holding gain (loss) of held-to-maturity securities transferred to the trading security category and the cumulative unrealized gain (loss) which was included in other comprehensive income (a separate component of shareholders' equity) for available-for-sale securities transferred to trading securities during the period. Additionally, this item would include any losses recognized for other than temporary impairments (OTTI) of the subject investments in debt and equity securities.

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