|
Debt (Long-Term Debt Outstanding) (Details) (USD $)
In Thousands, unless otherwise specified |
Dec. 31, 2011
|
Dec. 31, 2010
|
|---|---|---|
| Debt Instrument [Line Items] | ||
| Long-term debt | $ 1,249,281 | $ 1,249,221 |
|
7.456% Senior Notes Due 2018 [Member]
|
||
| Debt Instrument [Line Items] | ||
| Long-term debt | 500,000 | 500,000 |
|
5.95% Senior Notes Due 2020 [Member]
|
||
| Debt Instrument [Line Items] | ||
| Long-term debt | $ 749,281 | $ 749,221 |