| Dilutive weighted average securities were excluded from the calculation of diluted net income (loss) per share attributable to common stockholders during the periods |
The following potentially dilutive average number of securities were excluded from the calculation of diluted net income per share attributable to common stockholders during the periods presented as the effect was anti-dilutive: | | | | | | | | | | | Year Ended December 31, | | 2016 | | 2015 | | 2014 | Options to purchase common stock | 43,513 |
| | 87,026 |
| | 87,026 |
| Stock appreciation rights | 2,422,716 |
| | 2,072,130 |
| | 1,400,824 |
| Warrants to purchase common stock | — |
| | — |
| | 17,916 |
| 2019 Convertible notes | 7,895,675 |
| | 10,838,218 |
| | 6,295,075 |
| 2036 Convertible notes | 8,209,651 |
| | — |
| | — |
| Total | 18,571,555 |
| | 12,997,374 |
| | 7,800,841 |
|
|
| Calculation of diluted net income per share |
The following table presents the calculation of diluted net income per share for the years ended December 31, 2016, 2015 and 2014 (in thousands, except share and per share data): | | | | | | | | | | | | | | 2016 | | 2015 | | 2014 | Net income (loss) attributable to the Company's common stockholders - Basic | $ | 43,453 |
| | $ | (151,392 | ) | | $ | 81,620 |
| Plus: distributed dividends to Preferred Stockholders | — |
| | — |
| | 40 |
| Plus (less): effect of participating securities | 874 |
| | — |
| | (418 | ) | Net income (loss) attributable to common stockholders | 44,327 |
| | (151,392 | ) | | 81,242 |
| Less: effect of participating securities | (874 | ) | | — |
| | — |
| Net income (loss) attributable to the Company's common stockholders - Diluted | $ | 43,453 |
| | $ | (151,392 | ) | | $ | 81,242 |
| Shares: | | | | | | Weighted-average shares outstanding - Basic | 40,897,549 |
| | 43,958,803 |
| | 40,740,411 |
| Adjustment to reflect stock appreciation right conversions | 5,311 |
| | — |
| | 9,502 |
| Weighted-average shares outstanding - Diluted | 40,902,860 |
| | 43,958,803 |
| | 40,749,913 |
|
| | | | | | Net income (loss) per share attributable to common stockholders - Diluted | $ | 1.06 |
| | $ | (3.44 | ) | | $ | 1.99 |
|
|