Fair Value Measurements - Additional Information (Details) - USD ($) $ in Thousands |
Dec. 31, 2015 |
Dec. 31, 2014 |
Jun. 30, 2014 |
---|---|---|---|
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||
Unamortized discount | $ (25,704) | $ (32,256) | |
2% Convertible Notes | |||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||
Principal amount of Senior Notes | 201,250 | $ 201,250 | $ 201,300 |
Unamortized discount | $ 25,700 |