v3.3.0.814
Debt - Additional Information (Detail) - USD ($)
shares in Millions
3 Months Ended 6 Months Ended
Apr. 14, 2015
Jun. 30, 2015
Jun. 30, 2014
Jun. 30, 2015
Jun. 30, 2014
Debt Instrument [Line Items]          
Exercise of detachable warrants 0.7        
2021 notes | Level 2          
Debt Instrument [Line Items]          
Fair value of the notes   $ 365,300,000   $ 365,300,000  
Warrant          
Debt Instrument [Line Items]          
Non cash fair value adjustment on detachable warrants exercise     $ 1,200,000   $ 0
Interest Expense | Warrant          
Debt Instrument [Line Items]          
Non cash fair value adjustment on detachable warrants exercise   (4,730,000) $ 1,178,000 (4,563,000) $ (19,000)
2013 facility          
Debt Instrument [Line Items]          
Line of credit facility outstanding   55,000,000   55,000,000  
Line of credit facility maximum borrowing capacity   $ 175,000,000   $ 175,000,000  
Weighted average interest rate of debt outstanding   2.00%   2.00%