|
Senior and Senior Subordinated Notes (Details) (USD $)
In Thousands, unless otherwise specified |
Jun. 30, 2012
|
Dec. 31, 2011
|
|---|---|---|
| Components of senior and senior subordinated notes | ||
| Senior and senior subordinated notes | $ 596,054 | $ 606,409 |
|
6.25% senior notes due 2015 [Member]
|
||
| Components of senior and senior subordinated notes | ||
| Senior and senior subordinated notes | 0 | 284,549 |
|
7.731% senior subordinated notes due 2017 [Member]
|
||
| Components of senior and senior subordinated notes | ||
| Senior and senior subordinated notes | 99,825 | 125,875 |
|
7.15% senior notes due 2020 [Member]
|
||
| Components of senior and senior subordinated notes | ||
| Senior and senior subordinated notes | 196,229 | 195,985 |
|
7.00% senior notes due 2022 [Member]
|
||
| Components of senior and senior subordinated notes | ||
| Senior and senior subordinated notes | $ 300,000 | $ 0 |