Commitments and Contingencies - Quantitative information about operating leases (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2026	Mar. 31, 2025
Lease cost
Operating lease cost	$ 218	$ 207
Short-term lease cost	124	13
Variable lease cost	21
Sub-lease income		(36)
Total	361	184
Other information
Operating cash flows from operating leases	(281)	(187)
U.K
Lease cost
Operating lease cost	165	154
Short-term lease cost	51	13
Variable lease cost	20
Sub-lease income		(36)
Total	236	131
Other information
Operating cash flows from operating leases	$ (210)	$ (164)
Weighted-average remaining lease term - operating leases	6 years 10 months 24 days	7 years 2 months 12 days
Weighted-average discount rate - operating leases	12.00%	12.00%
U.S
Lease cost
Operating lease cost	$ 53	$ 53
Short-term lease cost	73
Variable lease cost	1
Total	126	53
Other information
Operating cash flows from operating leases	$ (71)	$ (23)
Weighted-average remaining lease term - operating leases	4 months 24 days	1 year 1 month 6 days
Weighted-average discount rate - operating leases	12.00%	12.00%

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Amount of lease cost recognized by lessee for lease contract.

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Remaining lease term of operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Amount of single lease cost, calculated by allocation of remaining cost of lease over remaining lease term. Includes, but is not limited to, single lease cost, after impairment of right-of-use asset, calculated by amortization of remaining right-of-use asset and accretion of lease liability.

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Amount of cash outflow from operating lease, excluding payments to bring another asset to condition and location necessary for its intended use.

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Weighted average discount rate for operating lease calculated at point in time.

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Amount of short-term lease cost, excluding expense for lease with term of one month or less.

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Amount of sublease income excluding finance and operating lease expense.

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Amount of variable lease cost, excluded from lease liability, recognized when obligation for payment is incurred for finance and operating leases.

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