Commitments and Contingencies - Quantitative information about operating leases (Details) - USD ($) $ in Thousands	6 Months Ended
Jun. 30, 2026	Jun. 30, 2025
Lease cost
Operating lease cost	$ 435	$ 423
Short-term lease cost	246	27
Variable lease cost	41
Sub-lease income		(73)
Total	722	377
Other information
Operating cash flows from operating leases	(178)	(395)
U.K
Lease cost
Operating lease cost	329	318
Short-term lease cost	103	27
Variable lease cost	36
Sub-lease income		(73)
Total	468	272
Other information
Operating cash flows from operating leases	$ (385)	$ (303)
Weighted-average remaining lease term - operating leases	6 years 10 months 24 days	7 years
Weighted-average discount rate - operating leases	12.00%	12.00%
U.S
Lease cost
Operating lease cost	$ 106	$ 105
Short-term lease cost	143
Variable lease cost	5
Total	254	105
Other information
Operating cash flows from operating leases	$ (143)	$ (92)
Weighted-average remaining lease term - operating leases	2 months 12 days	10 months 24 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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- Definition

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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