Government assistance programs (Details) - USD ($)	1 Months Ended	3 Months Ended		6 Months Ended
	Jul. 31, 2020	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021	May 31, 2021	Mar. 27, 2020
Unusual or Infrequent Item, or Both [Line Items]
Contra-research and development expense		$ 600,000		$ 600,000
Refundable employee retention credit								$ 800,000
Contra General And Administrative Expense				200,000
Contra expenses			$ 0		$ 0
Employee retention credit receivable		847,000		847,000		$ 0
Other Transaction Authority for Prototype Agreement
Unusual or Infrequent Item, or Both [Line Items]
Grants Receivable	$ 13,300,000						$ 17,600,000
Payment period of reimbursement contract	30 days
Contra-research and development expense		10,000.00	$ 4,100,000	600,000	$ 8,100,000
Prepaid expenses and other current assets		200,000		200,000		2,700,000
Deferred research obligation liability		10,000.00		10,000.00		2,000,000.0
Grant expected to be received		0		0		$ 1,600,000
Grants receivable current		$ 17,400,000		$ 17,400,000