Annual report pursuant to Section 13 and 15(d)

Senior, Senior Subordinated, Convertible Senior Notes (Details)

v2.4.0.6
Senior, Senior Subordinated, Convertible Senior Notes (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2012
Dec. 31, 2011
Components of senior and senior subordinated notes    
Senior, senior subordinated, convertible senior notes $ 722,797 $ 606,409
Line of credit facility, amount outstanding 0  
6.25% senior notes due 2015 [Member]
   
Components of senior and senior subordinated notes    
Senior, senior subordinated, convertible senior notes 0 284,549
7.731% senior subordinated notes due 2017 [Member]
   
Components of senior and senior subordinated notes    
Senior, senior subordinated, convertible senior notes 99,825 125,875
7.15% senior notes due 2020 [Member]
   
Components of senior and senior subordinated notes    
Senior, senior subordinated, convertible senior notes 196,472 195,985
7.00% senior notes due 2022 [Member]
   
Components of senior and senior subordinated notes    
Senior, senior subordinated, convertible senior notes 300,000 0
1.875% convertible senior notes due 2032 [Member]
   
Components of senior and senior subordinated notes    
Senior, senior subordinated, convertible senior notes 126,500 0
Revolving Credit Facility [Member]
   
Components of senior and senior subordinated notes    
Line of credit facility, amount outstanding $ 0 $ 0