Net Loss per Share

12 Months Ended

Dec. 31, 2019

Earnings Per Share [Abstract]

Earnings Per Share [Text Block]

Net Loss per Share

Basic net loss per share is computed using the weighted-average number of shares of common stock outstanding during the period. Diluted net loss per share is calculated using the weighted-average number of shares of common stock plus, when dilutive, potential common shares outstanding using the treasury-stock method. Potential common shares outstanding include stock options, unvested restricted stock awards and restricted stock units, and warrants.

The following potentially dilutive equity securities were not included in the diluted earnings per common share calculation because they would have had an antidilutive effect:

	As of December 31,
	2019	2018	2017
Stock options	2,097,978	2,621,503	4,006,399
Restricted stock awards and restricted stock units	581,943	451,160	256,842
Warrants	—	480,000	810,000