|
Fair Value Disclosures (Details 1) (USD $)
In Thousands, unless otherwise specified |
Jun. 30, 2013
|
Dec. 31, 2012
|
|---|---|---|
|
7.731% senior subordinated notes due 2017 [Member]
|
||
| Fair value of fixed-rate debt | ||
| Aggregate Principal | $ 99,800 | |
|
7.731% senior subordinated notes due 2017 [Member] | Level 2 [Member]
|
||
| Fair value of fixed-rate debt | ||
| Aggregate Principal | 99,825 | |
| Estimated Fair Value | 102,950 | |
|
4.50% senior notes due two thousand eighteen [Member]
|
||
| Fair value of fixed-rate debt | ||
| Aggregate Principal | 175,000 | |
|
4.50% senior notes due two thousand eighteen [Member] | Level 2 [Member]
|
||
| Fair value of fixed-rate debt | ||
| Aggregate Principal | 175,000 | |
| Estimated Fair Value | 173,250 | |
|
7.15% senior notes due 2020 [Member] | Level 2 [Member]
|
||
| Fair value of fixed-rate debt | ||
| Aggregate Principal | 200,000 | 200,000 |
| Estimated Fair Value | 220,000 | 220,760 |
|
7.00% senior notes due 2022 [Member] | Level 2 [Member]
|
||
| Fair value of fixed-rate debt | ||
| Aggregate Principal | 300,000 | 300,000 |
| Estimated Fair Value | 329,250 | 328,500 |
|
1.875% convertible senior notes due 2032 [Member] | Level 2 [Member]
|
||
| Fair value of fixed-rate debt | ||
| Aggregate Principal | 126,500 | 126,500 |
| Estimated Fair Value | $ 137,885 | $ 127,449 |