Redeemable Convertible Preferred Stock (Details) $ in Millions		1 Months Ended				12 Months Ended
	Nov. 01, 2018 shares	May 31, 2020 shares	Apr. 30, 2020 shares	Jan. 31, 2020 shares	Nov. 30, 2018 USD ($) shares	Dec. 31, 2019 USD ($) shares	Dec. 31, 2020 USD ($) installment shares
Series C Redeemable Convertible Preferred Stock
Redeemable preferred stock
Number of shares of common stock issued on conversion of preferred stock		1,858,256	923,819
Number of preferred shares that had been converted to common stock		1,750	870
Series E Redeemable Convertible Preferred Stock
Redeemable preferred stock
Shares issued (in shares)					35,000
Net proceeds from public offering | $					$ 30.9
Number of monthly installments | installment							13
Redemption value for each installment | $							$ 2.7
Shares outstanding (in shares)						500	0
Preferred stock, dividends | $						$ 1.8
Series E Preferred Stock
Redeemable preferred stock
Shares issued (in shares)	35,000
Number of preferred shares that had been converted to common stock				500		30,462