|
Fair Value Fair Value (Details 2) (USD $)
In Millions, unless otherwise specified |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
|
Sep. 30, 2012
|
Sep. 30, 2011
|
Sep. 30, 2012
|
Sep. 30, 2011
|
|
|
Fair Value, Inputs, Level 2 [Member]
|
||||
| Fair Value Transfers Between Level 1, Level 2 and Level 3 [Line Items] | ||||
| Transfers into Level 1 | $ 0 | $ 0 | $ 0 | $ 0 |
| Transfers into Level 3 | 0 | (7) | 29 | (4) |
|
Fair Value, Inputs, Level 3 [Member]
|
||||
| Fair Value Transfers Between Level 1, Level 2 and Level 3 [Line Items] | ||||
| Transfers into Level 1 | 0 | 0 | 0 | 0 |
| Transfers into Level 2 | 0 | 42 | 2 | 24 |
|
Fair Value, Inputs, Level 1 [Member]
|
||||
| Fair Value Transfers Between Level 1, Level 2 and Level 3 [Line Items] | ||||
| Transfers into Level 2 | 0 | 0 | 0 | 0 |
| Transfers into Level 3 | $ 0 | $ 0 | $ 0 | $ 0 |