Summary of Significant Accounting Policies - Loss Per Share (Details) - shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Net Earnings per Share
Securities excluded from diluted loss per share calculation (in shares)	33,307,113	12,968,474
Options to purchase common stock
Net Earnings per Share
Securities excluded from diluted loss per share calculation (in shares)	6,467,956	8,598,149
Unvested restricted stock awards
Net Earnings per Share
Securities excluded from diluted loss per share calculation (in shares)	146,800	146,800
Unvested restricted stock units
Net Earnings per Share
Securities excluded from diluted loss per share calculation (in shares)	265,494	1,452,744
Warrants to purchase common stock
Net Earnings per Share
Securities excluded from diluted loss per share calculation (in shares)	26,426,863	2,770,781