Net Income Per Share - Earnings Per Share (Details) (USD $)
In Thousands, except Per Share data, unless otherwise specified
3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Basic:    
Net (loss) income $ 12,786 $ (22,354)
Less: net income allocated to participating securities 0 0
Net income (loss) attributable to common shareholders 12,786 (22,354)
Weighted-average common shares outstanding 43,184 702
Basic net (loss) income per share (in dollars per share) $ 0.30 $ (31.86)
Diluted:    
Less: net income allocated to participating securities 0 0
Net income (loss) attributable to common shareholders $ 12,786 $ (22,354)
Effect of dilutive potential common shares 1,434 0
Weighted-average common shares outstanding-diluted 44,618 702
Diluted net (loss) income per share (in dollars per share) $ 0.29 $ (31.86)