Fair Value Disclosures (Details 1) (USD $)
In Thousands, unless otherwise specified |
Dec. 31, 2012
7.731% senior subordinated notes due 2017 [Member]
Level 2 [Member]
|
Dec. 31, 2013
Senior Notes Due Two Thousand Eighteen [Member] [Domain]
|
Dec. 31, 2013
Senior Notes Due Two Thousand Eighteen [Member] [Domain]
Level 2 [Member]
|
Dec. 31, 2013
7.15% senior notes due 2020 [Member]
Level 2 [Member]
|
Dec. 31, 2012
7.15% senior notes due 2020 [Member]
Level 2 [Member]
|
Apr. 30, 2012
7.00% senior notes due 2022 [Member]
|
Dec. 31, 2013
7.00% senior notes due 2022 [Member]
Level 2 [Member]
|
Dec. 31, 2012
7.00% senior notes due 2022 [Member]
Level 2 [Member]
|
Dec. 31, 2013
1.875% convertible senior notes due 2032 [Member]
Level 2 [Member]
|
Dec. 31, 2012
1.875% convertible senior notes due 2032 [Member]
Level 2 [Member]
|
---|---|---|---|---|---|---|---|---|---|---|
Debt Instrument [Line Items] | ||||||||||
Aggregate Principal | $ 99,825 | $ 175,000 | $ 175,000 | $ 300,000 | $ 200,000 | $ 300,000 | $ 300,000 | $ 300,000 | $ 126,500 | $ 126,500 |
Fair value of fixed-rate debt | ||||||||||
Estimated Fair Value | $ 102,950 | $ 174,125 | $ 325,500 | $ 220,760 | $ 318,750 | $ 328,500 | $ 142,154 | $ 127,449 |