Stockholders' equity (deficit) - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2023	Dec. 31, 2022
Equity [Abstract]
Options awards outstanding, Beginning balance	172
Options awards outstanding, Expired	(90)
Options awards outstanding, Ending balance	82	172
Options awards outstanding, weighted average exercise price, Beginning balance	$ 228.28
Options awards outstanding, weighted average exercise price, Expired	203.84
Options awards outstanding, weighted average exercise price, Ending balance	$ 255.03	$ 228.28
Options awards outstanding, aggregate intrinsic value	$ 0
Options awards outstanding, Weighted Average Remaining Contractual Life (in Years)	3 years 6 months	3 years 7 months 6 days
Options awards outstanding, Weighted Average Remaining Contractual Life (in Years), Expired	3 years 3 months 18 days
Options awards exercisable, Beginning balance	170
Options awards exercisable, Expired	(90)
Options awards exercisable, Ending balance	80	170
Options awards exercisable, weighted average exercise price, Beginning balance	$ 229.43
Options awards exercisable, weighted average exercise price, Expired	203.84
Options awards exercisable, weighted average exercise price, Ending balance	$ 258.5	$ 229.43
Options awards exercisable, Aggregate Intrinsic Value	$ 0
Options awards exercisable, Weighted Average Remaining Contractual Life (in Years)	3 years 6 months	3 years 7 months 6 days
Options awards exercisable, Weighted Average Remaining Contractual Life (in Years), Expired	3 years 3 months 18 days