Common Stock Warrant Liability - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	9 Months Ended
	Sep. 30, 2021	Dec. 31, 2020	Dec. 27, 2018	Oct. 12, 2017
Class Of Warrant Or Right [Line Items]
Common stock par value per share	$ 0.001	$ 0.001
Series W Common Stock [Member]
Class Of Warrant Or Right [Line Items]
Warrants issued to purchase common stock				$ 60.0
Additional non-refundable payment upon extension of expiration			$ 40.0
Common stock par value per share	$ 0.001
Exercise price of warrants	$ 630.0
Escrow holdback of exercise price of warrants	92.0
Shareholder representative holdback of exercise price of warrants	0.5
Potential aggregate payments for sales based and operating milestones	827.0
Potential aggregate payments for regulatory milestones	185.0
Gain on expiration of warrants	$ 5.0
Share Purchase Agreement [Member] | Nonvoting Common Stock [Member]
Class Of Warrant Or Right [Line Items]
Common stock par value per share	$ 0.001
Series G Common Stock [Member]
Class Of Warrant Or Right [Line Items]
Common stock par value per share	$ 0.01