Quarterly report pursuant to Section 13 or 15(d)

Recent Developments, Liquidity and Management???s Plans - Summary of Milestone Events Payment (Details) (Parenthetical)

v3.21.2
Recent Developments, Liquidity and Management’s Plans - Summary of Milestone Events Payment (Details) (Parenthetical)
$ in Millions
 9 Months Ended
Sep. 30, 2021
USD ($)
d
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]  
Debt Instrument, Convertible, Threshold Consecutive Trading Days | d 10
Milestone Period One [Member]  
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]  
Debt Instrument, Convertible, Threshold Trading Days | d 10
Debt Instrument, Convertible, Threshold Consecutive Trading Days | d 20
[custom:MarketCapitalization] $ 500
Payments to Milestone $ 20
Milestone Period Two [Member]  
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]  
Debt Instrument, Convertible, Threshold Trading Days | d 10
Debt Instrument, Convertible, Threshold Consecutive Trading Days | d 20
[custom:MarketCapitalization] $ 250
Payments to Milestone 20
Milestone Period Two [Member] | Maximum [Member]  
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]  
[custom:MarketCapitalization] 1,000
Payments to Milestone $ 10
Milestone Period Three [Member]  
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]  
Debt Instrument, Convertible, Threshold Trading Days | d 10
Debt Instrument, Convertible, Threshold Consecutive Trading Days | d 20
[custom:MarketCapitalization] $ 1,000
Payments to Milestone $ 25
Milestone Period Four [Member]  
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]  
Debt Instrument, Convertible, Threshold Trading Days | d 10
Debt Instrument, Convertible, Threshold Consecutive Trading Days | d 20
[custom:MarketCapitalization] $ 1,000
Milestone Period Four [Member] | Maximum [Member]  
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]  
Payments to Milestone $ 25