Derivative Financial Instruments Effect of Net Investment Hedge Nonderivative Financial Instrument on OCI (Details) (USD $) In Thousands | 3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2011 | Sep. 30, 2010 | Sep. 30, 2011 | Sep. 30, 2010 | |
| Gain (loss) recognized in OCI on derivative, (Effective Portion) [Abstract] | ||||
| Before tax | $ 645 | $ (19,703) | $ (14,278) | $ 19,795 |
| After tax | $ 408 | $ (12,149) | $ (8,854) | $ 12,203 |