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Assets And Liabilities Measured At Fair Value Assets and Liabilities Measured at Fair Value (Realized and Unrealized Gains (Losses) on Financial Assets (Details) (USD $)
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3 Months Ended | 9 Months Ended | 3 Months Ended | 9 Months Ended | 3 Months Ended | 9 Months Ended | 3 Months Ended | 9 Months Ended | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
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Sep. 30, 2014
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Sep. 30, 2013
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Sep. 30, 2014
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Sep. 30, 2013
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Oct. 17, 2013
1.375% Cash Convertible Senior Notes due 2023
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Oct. 31, 2013
1.375% Cash Convertible Senior Notes due 2023
Level 2
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Sep. 30, 2014
Fair Value Option Securities
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Sep. 30, 2013
Fair Value Option Securities
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Sep. 30, 2014
Fair Value Option Securities
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Sep. 30, 2013
Fair Value Option Securities
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Sep. 30, 2014
Convertible Notes Payable
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Sep. 30, 2014
Convertible Notes Payable
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Sep. 30, 2014
Other Financial Instruments
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Sep. 30, 2013
Other Financial Instruments
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Sep. 30, 2014
Other Financial Instruments
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Sep. 30, 2013
Other Financial Instruments
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| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||||||||||||||||
| Realized and unrealized (gains) losses on financial instruments, net | $ (15,000,000) | $ 64,000,000 | $ (55,000,000) | $ 222,000,000 | $ (30,000,000) | $ 53,000,000 | $ 33,000,000 | $ 189,000,000 | $ 41,000,000 | $ 18,000,000 | $ (26,000,000) | $ 11,000,000 | $ (106,000,000) | $ 33,000,000 | ||
| Debt face amount | $ 1,000,000,000 | $ 1,000,000,000 | ||||||||||||||