8.  Earnings/ (Loss) Per Share 
The following table presents the calculation of basic and diluted earnings (loss) per common share (in thousands, except per share amounts):  
| 
   
 | 
 Three Months Ended 
 | 
   
 | 
   
 | 
 Nine Months Ended 
 | 
   
 | 
 
| 
   
 | 
 September 30, 
 | 
   
 | 
   
 | 
 September 30, 
 | 
   
 | 
 
| 
   
 | 
 2017 
 | 
   
 | 
   
 | 
 2016 
 | 
   
 | 
   
 | 
 2017 
 | 
   
 | 
   
 | 
 2016 
 | 
   
 | 
 
| 
 Net income (loss) 
 | 
 $ 
 | 
 (1,297 
 | 
 ) 
 | 
   
 | 
 $ 
 | 
 45,928 
 | 
   
 | 
   
 | 
 $ 
 | 
 56,317 
 | 
   
 | 
   
 | 
 $ 
 | 
 (265,503 
 | 
 ) 
 | 
 
| 
 Less portion allocated to nonvested shares 
 | 
   
 | 
 — 
 | 
   
 | 
   
 | 
   
 | 
 1,689 
 | 
   
 | 
   
 | 
   
 | 
 2,349 
 | 
   
 | 
   
 | 
   
 | 
 — 
 | 
   
 | 
 
| 
 Net income (loss) allocated to common shares 
 | 
 $ 
 | 
 (1,297 
 | 
 ) 
 | 
   
 | 
 $ 
 | 
 44,239 
 | 
   
 | 
   
 | 
 $ 
 | 
 53,968 
 | 
   
 | 
   
 | 
 $ 
 | 
 (265,503 
 | 
 ) 
 | 
 
| 
 Weighted average common shares outstanding 
 | 
   
 | 
 137,575 
 | 
   
 | 
   
 | 
   
 | 
 92,243 
 | 
   
 | 
   
 | 
   
 | 
 137,547 
 | 
   
 | 
   
 | 
   
 | 
 81,748 
 | 
   
 | 
 
| 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
 
| 
 Basic and diluted earnings (loss) per common share 
 | 
 $ 
 | 
 (0.01 
 | 
 ) 
 | 
   
 | 
 $ 
 | 
 0.48 
 | 
   
 | 
   
 | 
 $ 
 | 
 0.39 
 | 
   
 | 
   
 | 
 $ 
 | 
 (3.25 
 | 
 ) 
 | 
 
| 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
 
| 
 Shares excluded due to being anti-dilutive (weighted-average) 
 | 
   
 | 
 7,709 
 | 
   
 | 
   
 | 
   
 | 
 — 
 | 
   
 | 
   
 | 
   
 | 
 — 
 | 
   
 | 
   
 | 
   
 | 
 3,833 
 | 
   
 | 
 
 
 
  
 
 |