Net Loss Per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Basic and diluted net loss per common share calculation:
Net loss	$ (15,076)	$ (12,501)
Weighted average common shares outstanding - basic and dilutive (in shares)	53,426	41,427
Net loss per common shares - basic and diluted (in dollars per share)	$ (0.28)	$ (0.30)
Anti-dilutive securities
Total (in shares)	8,036	6,508
Stock options outstanding
Anti-dilutive securities
Total (in shares)	6,635	5,844
Restricted stock units
Anti-dilutive securities
Total (in shares)	1,401	664

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

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