Fair value measurements - CVR and Warrants Rollforward (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Warrants Liabilities [Roll Forward]
Balance at December 31, 2021			$ 1,769
Change in fair value of warrants	$ (9)	$ (81)	(1,746)	$ (91)
Balance at September 30, 2022	23		23
Fair Value, Inputs, Level 3 [Member]
Warrants Liabilities [Roll Forward]
Balance at December 31, 2021			1,769
Change in fair value of warrants			(1,746)
Balance at September 30, 2022	23		23
CVR Liabilities | Fair Value, Inputs, Level 3 [Member]
Contingent Value Rights [Roll Forward]
Balance at December 31, 2021			22,531
Change in fair value of CVRs			7,569
Balance at September 30, 2022	$ 30,100		$ 30,100