|
Debt - Outstanding Convertible Debt and Related Deferred Financing Costs (Detail) (USD $)
In Thousands, unless otherwise specified |
Mar. 31, 2015
|
Dec. 31, 2014
|
Jun. 30, 2011
|
Jun. 30, 2014
|
|---|---|---|---|---|
| Debt Instrument [Line Items] | ||||
| Unamortized discount | $ (30,655) | $ (32,256) | ||
| Long-term debt, net of discount | 170,595 | 168,994 | ||
| Deferred financing costs | 4,693 | 4,974 | ||
| 3.75% Convertible Notes | ||||
| Debt Instrument [Line Items] | ||||
| Principal amount of Senior Notes | 143,800 | |||
| 2% Convertible Notes | ||||
| Debt Instrument [Line Items] | ||||
| Principal amount of Senior Notes | 201,250 | 201,250 | 201,300 | |
| Unamortized discount | (30,700) | |||
| Long-term debt, net of discount | $ 170,600 |