Fair Value Disclosures (Details 1) (USD $)
In Thousands, unless otherwise specified |
Sep. 30, 2013
|
Dec. 31, 2012
|
---|---|---|
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 | 171,938 | |
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 | 216,000 | 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 | 318,000 | 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 | $ 135,829 | $ 127,449 |