v2.4.0.6
Amounts Recorded for Notes (Detail) (USD $)
In Thousands, unless otherwise specified
Jun. 30, 2012
Dec. 31, 2011
Debt Instrument [Line Items]    
Outstanding principal $ 200,000 $ 175,000
Unamortized OID (40,203) (36,494)
Liability component 159,797 138,506
Equity component, net of tax $ 27,092 $ 23,785