|
Income Taxes (Details) (USD $)
In Millions, unless otherwise specified |
3 Months Ended | 9 Months Ended |
|---|---|---|
|
Sep. 30, 2011
|
Sep. 30, 2011
|
|
| Income Tax Disclosure [Abstract] | ||
| Change in unrealized gain (loss) on marketable securities, income tax expense (benefit) | $ 0.6 | $ (0.5) |