|
Interest and Other Nonoperating Income (Details) (USD $)
In Millions, unless otherwise specified |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
|
Sep. 30, 2012
|
Sep. 30, 2011
|
Sep. 30, 2012
|
Sep. 30, 2011
|
|
| Schedule of Trading Securities and Other Trading Assets [Line Items] | ||||
| Interest and other income | $ 1.5 | $ 1.3 | $ 6.3 | $ 6.8 |