Earnings per Share

12 Months Ended

Dec. 31, 2015

Basic earnings per common share are computed by dividing net income attributable to common stockholders by the weighted-average number of shares of common stock outstanding during the period. Diluted earnings per common share are computed by dividing net income attributable to common stockholders by the combined weighted-average number of shares of common stock outstanding and the potential dilution of stock options, warrants, RSUs, PRSUs, Convertible Notes and the Company’s Series A Convertible Perpetual Preferred Stock, par value $0.001 per share, outstanding during the period, if dilutive. The weighted-average of potentially dilutive securities excluded from the computation of diluted earnings per share is shown in the table below.



	Year Ended December 31,
	2015	2014	2013
Basic weighted-average common stock outstanding	92,755,919	53,629,962	22,752,320
Potentially Dilutive Securities:
Shares underlying the conversion of preferred stock to common stock	10,438,426	10,483,052	10,607,309
Shares underlying the conversion of the convertible senior notes	4,327,654	7,342,864	8,623,331
Shares underlying warrants to purchase common stock	8,574,412	8,202,468	6,900,642
Shares underlying stock options to purchase common stock	823,352	555,977	356,815
Shares underlying restricted stock units and performance-based restricted stock units	1,519,776	797,026	367,183
	25,683,620	27,381,387	26,855,280
Diluted weighted-average shares outstanding	118,439,539	81,011,349	49,607,600

The impact of this dilution was not reflected in the earnings per share calculations in the consolidated statements of operations because the impact was anti-dilutive. The treasury stock method was used to determine the shares underlying warrants, stock options, RSUs and PRSUs for potential dilution with an average market price of $38.79 per share, $31.30 per share and $19.69 per share for the years ended December 31, 2015, 2014 and 2013, respectively.