|
Financial Derivatives (Narrative) (Details) (USD $)
In Millions, unless otherwise specified |
9 Months Ended | 12 Months Ended |
|---|---|---|
|
Sep. 30, 2012
|
Dec. 31, 2011
|
|
| Derivative [Line Items] | ||
| Low range of spread on written credit derivatives | 0.09% | 3.50% |
| High range of spread on written credit derivatives | 4.58% | 4.42% |
|
Credit Default Swap, Selling Protection [Member]
|
||
| Derivative [Line Items] | ||
| Total net up-front payments received | $ 17.8 | $ 9.6 |