XML 76 R83.htm IDEA: XBRL DOCUMENT v2.4.0.6
Senior Notes - Summary of Carrying Amounts of Debt and Equity Balances (Detail) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2012
Dec. 31, 2011
Debt Instrument [Line Items]    
Principal amount of senior convertible notes $ 450,000  
Senior Convertible Notes [Member]
   
Debt Instrument [Line Items]    
Carrying value of equity component 52,497 69,217
Principal amount of senior convertible notes 350,000 529,509
Remaining unamortized debt discount (32,120) (43,004)
Net carrying value of senior convertible notes $ 317,880 $ 486,505