Summary of significant accounting policies - Additional Information (Details)			1 Months Ended	3 Months Ended			9 Months Ended
	Sep. 25, 2023	Jun. 08, 2023	Mar. 31, 2023 USD ($)	Sep. 30, 2023 USD ($) shares	Mar. 31, 2023 USD ($)	Sep. 30, 2022 USD ($) shares	Sep. 30, 2023 USD ($) shares	Sep. 30, 2022 USD ($) shares
Lessee, Lease, Description [Line Items]
Stockholders' equity, reverse stock split	0.20
Impairment of property and equipment			$ 3,400,000	$ 0	$ 3,400,000	$ 0	$ 3,418,000	$ 0
Allowance for credit loss				0			0
Unrealized loss				$ 22,800,000			$ 22,800,000
Expected dividends						0.00%	0.00%	0.00%
Prefunded Warrants
Lessee, Lease, Description [Line Items]
Outstanding pre-funded warrants (in shares) | shares				2,296,602		2,532,602	2,296,602	2,532,602
Minimum
Lessee, Lease, Description [Line Items]
Stockholders' equity, reverse stock split		0.50
Property and equipment, useful life				3 years			3 years
Maximum
Lessee, Lease, Description [Line Items]
Stockholders' equity, reverse stock split		0.20
Property and equipment, useful life				7 years			7 years
Maximum | Office space
Lessee, Lease, Description [Line Items]
Lease term				12 months			12 months