Quarterly report pursuant to Section 13 or 15(d)

Debt (Details 2)

v2.4.0.6
Debt (Details 2) (USD $)
In Thousands, unless otherwise specified
Mar. 31, 2012
Dec. 31, 2011
Carrying amount and estimated fair value of debt    
Debt, net $ 2,418,078 $ 2,426,303
4.25% Exchangeable Senior Notes
   
Carrying amount and estimated fair value of debt    
Debt, net 228,175 227,283
Carrying Amount
   
Carrying amount and estimated fair value of debt    
Variable- rate debt 1,135,621 1,141,549
Debt, net 2,418,078 2,426,303
Carrying Amount | 4.25% Exchangeable Senior Notes
   
Carrying amount and estimated fair value of debt    
Fixed-rate debt 228,175 227,283
Carrying Amount | Other fixed-rate debt
   
Carrying amount and estimated fair value of debt    
Fixed-rate debt 1,054,282 1,057,471
Total Estimated Fair Value
   
Carrying amount and estimated fair value of debt    
Variable- rate debt 1,135,847 1,139,856
Debt, net 2,424,288 2,432,357
Total Estimated Fair Value | 4.25% Exchangeable Senior Notes
   
Carrying amount and estimated fair value of debt    
Fixed-rate debt 239,331 238,077
Total Estimated Fair Value | Other fixed-rate debt
   
Carrying amount and estimated fair value of debt    
Fixed-rate debt $ 1,049,110 $ 1,054,424