|
Financial Instruments (Details Textual) (USD $)
In Millions, unless otherwise specified |
3 Months Ended | 9 Months Ended | 12 Months Ended | ||
|---|---|---|---|---|---|
|
Sep. 30, 2012
|
Sep. 30, 2011
|
Sep. 30, 2012
|
Sep. 30, 2011
|
Dec. 31, 2011
|
|
| Financial Instruments (Textual) [Abstract] | |||||
| Federal Deposit Insurance Corporation guaranteed senior notes issued under the Temporary Liquidity Guarantee Program | $ 89.1 | $ 89.1 | $ 214.0 | ||
| Original maturities of commercial paper and short-term debt securities | less than 90 days | ||||
| Average maturity of marketable securities, months | 13 months | 14 months | |||
| Impairments recognized in relation to our publicly-held strategic investments | 0 | ||||
| Impairment charges | $ 3.5 | $ 0.8 | $ 4.8 | $ 7.6 | |