Assets And Liabilities Measured At Fair Value Realized Unrealized Gain Loss (Details) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2015 |
Jun. 30, 2014 |
Jun. 30, 2015 |
Jun. 30, 2014 |
|
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||||
| Realized and unrealized gains (losses) on financial instruments, net | $ 32 | $ (41) | $ 28 | $ (66) |
| Fair Value Option Securities | ||||
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||||
| Realized and unrealized gains (losses) on financial instruments, net | 165 | 90 | 148 | 80 |
| Exchangeable Senior Debentures | ||||
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||||
| Realized and unrealized gains (losses) on financial instruments, net | $ (133) | $ (131) | $ (120) | $ (146) |