Carrying Values of Convertible Senior Debentures (Detail) (USD $)
In Thousands, unless otherwise specified |
Dec. 31, 2012
|
Dec. 31, 2011
|
---|---|---|
Debt Instrument [Line Items] | ||
Convertible senior debentures-non-current | $ 48,991 | $ 45,694 |
Convertible Senior Debentures due 2018
|
||
Debt Instrument [Line Items] | ||
Convertible senior debentures | 48,483 | |
Convertible Senior Debentures due 2014
|
||
Debt Instrument [Line Items] | ||
Convertible senior debentures | 67 | 45,253 |
Convertible Senior Debentures due 2024
|
||
Debt Instrument [Line Items] | ||
Convertible senior debentures | $ 441 | $ 441 |