Warrants -Summary of Outstanding Warrants (Details) - $ / shares	9 Months Ended
	Sep. 30, 2021	Jun. 24, 2020
Series E Redeemable Convertible Preferred Stock
Class Of Warrant Or Right [Line Items]
Warrant Issuance Date	2014-08
Shares of Common Stock Underlying Warrants	1,914
Exercise Price/Share	$ 352.65
Expiration Date	2024
Convertible Note Warrants
Class Of Warrant Or Right [Line Items]
Warrant Issuance Date	2014-12
Shares of Common Stock Underlying Warrants	9,651
Exercise Price/Share	$ 210.00
Expiration Date	2022
Common Stock Warrants
Class Of Warrant Or Right [Line Items]
Warrant Issuance Date	2016-03
Shares of Common Stock Underlying Warrants	3,021
Exercise Price/Share	$ 41.40
Expiration Date	2026
Common Stock Tranche one
Class Of Warrant Or Right [Line Items]
Warrant Issuance Date	2018-03
Shares of Common Stock Underlying Warrants	1,208
Exercise Price/Share	$ 115.95
Expiration Date	2028
SVB Term Loan
Class Of Warrant Or Right [Line Items]
Warrant Issuance Date	2020-06
Shares of Common Stock Underlying Warrants	42,894
Exercise Price/Share	$ 11.6565	$ 11.6565
Expiration Date	2030