Income taxes - Schedule of Effective Income Tax Rate Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Tax at federal statutory rate	$ (29,034)	$ (20,323)	$ (22,344)
State income taxes, net of federal benefit	57	(644)	1,330
Stock compensation	5,587	1,271	2,786
Foreign rate differential	25	(2)	0
Tax credits	(539)	(539)	(539)
Fair value changes - warrants	(1,564)	(619)	11,192
Valuation allowance	25,666	20,058	(6,812)
Non-deductible expenses	78	(2,031)	(485)
Convertible debt cancellation of indebtedness income	0	0	15,079
Other	29	35	168
Total tax provision (benefit)	$ 305	$ (2,794)	$ 375

Effective Income Tax Rate Reconciliation, Cancellation Of Indebtedness Income, Amount

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Amount of difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying domestic federal statutory income tax rate to pretax income (loss) from continuing operation, attributable to expense for award under share-based payment arrangement. Excludes expense determined to be nondeductible upon grant or after for award under share-based payment arrangement.

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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The amount of income tax expense or benefit for the period computed by applying the domestic federal statutory tax rates to pretax income from continuing operations.

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