Rights Offering and debt obligations - Additional Information (Details) - USD ($)				1 Months Ended					12 Months Ended
	Nov. 25, 2022	Nov. 23, 2022	Dec. 31, 2018	Nov. 30, 2022	Oct. 31, 2022	Jun. 30, 2022	Sep. 30, 2020	Jun. 30, 2019	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Jun. 28, 2022	Jun. 24, 2022	Sep. 30, 2021	Jun. 30, 2018
Debt Instrument [Line Items]
Net proceeds from issuance of common stock									$ 27,598,000
Conversion shares, fair value									150,978,000
Principal value										$ 15,000,000
Debt, final payment as percentage of original aggregate principal amount							6.00%
Interest expense									549,000	1,068,000	$ 1,920,000
Outstanding debt									0	15,257,000
Loss on extinguishment of debt									$ 772,000		$ 1,627,000
Common Stock
Debt Instrument [Line Items]
Issuance of shares									2,928,701		451,481
Converstion of common stock											1,409,819
PSC beneficially owned the conversion shares percentage									76.30%
Conversion shares, fair value				$ 151,000,000.0					$ 2,000
Common Stock | First Tranche
Debt Instrument [Line Items]
Converstion of common stock		15,000,000
Common Stock | Second Tranche
Debt Instrument [Line Items]
Converstion of common stock	821,299
2018 Loan Agreement
Debt Instrument [Line Items]
Aggregate principal amount															$ 12,500,000
Proceeds from debt financing			$ 7,000,000.0
Amendments 2018 Loan Agreement
Debt Instrument [Line Items]
Aggregate principal amount														$ 20,000,000.0
Proceeds from debt financing							$ 15,000,000.0	$ 5,000,000.0
Principal value								$ 12,000,000.0
Repayments on outstanding debt						$ 15,000,000.0	10,200,000
Prepayment fee						300
Final payment fee						900,000	9,500,000
Payments on existing term loan							$ 700,000
Debt, final payment as percentage of original aggregate principal amount							6.25%
Interest expense									500,000	$ 1,100,000	$ 1,000,000.0
Loss on extinguishment of debt						$ (800,000)
Amendments 2018 Loan Agreement | Series C Convertible Preferred Stock | Silicon Valley Bank
Debt Instrument [Line Items]
Warrants issued to purchase shares of convertible preferred stock								14,999
Amendments 2018 Loan Agreement | Series E Convertible Preferred Stock | Silicon Valley Bank
Debt Instrument [Line Items]
Warrants issued to purchase shares of convertible preferred stock							53,487
Amendments 2018 Loan Agreement | Wall Street Journal Prime Rate
Debt Instrument [Line Items]
Term loans, interest rate							1.00%
2022 Convertible Notes
Debt Instrument [Line Items]
Conversion shares, fair value									150,978,000
2022 Convertible Notes | First Tranche
Debt Instrument [Line Items]
Aggregate principal amount												$ 100,000,000.0	$ 125,000,000.0
2022 Convertible Notes | Second Tranche
Debt Instrument [Line Items]
Aggregate principal amount		$ 5,500,000							25,000,000.0
2022 Convertible Notes | General and Administrative
Debt Instrument [Line Items]
Gain (Loss) on Repurchase of Debt Instrument									$ 5,700,000
Rights Offering
Debt Instrument [Line Items]
Common stock offering price per share					$ 10.00
Common stock subscribed shares		2,928,701
Net proceeds from issuance of common stock		$ 27,600,000		$ 27,600,000
Rights Offering | Second Tranche
Debt Instrument [Line Items]
Common stock subscribed shares									3,750,000
Rights Offering | Common Stock
Debt Instrument [Line Items]
Issuance of shares					18,750,000