Quarterly report pursuant to Section 13 or 15(d)

Fair Value Disclosures (Details 1)

v2.4.0.8
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