Revenue - Schedule of total revenue disaggregated by geographic region (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Revenue by country of domicile:
Revenue	$ 547	$ 3,833	$ 12,921	$ 8,105
Japan
Revenue by country of domicile:
Revenue	$ 368	$ 2,151	$ 11,834	$ 4,454
Japan | Revenue Benchmark | Geographic Concentration Risk
Revenue by country of domicile:
Concentration risk	67.00%	56.00%	92.00%	55.00%
United States
Revenue by country of domicile:
Revenue	$ 170	$ 1,583	$ 1,031	$ 3,153
United States | Revenue Benchmark | Geographic Concentration Risk
Revenue by country of domicile:
Concentration risk	31.00%	41.00%	8.00%	39.00%
Other
Revenue by country of domicile:
Revenue	$ 9	$ 99	$ 56	$ 498
Other | Revenue Benchmark | Geographic Concentration Risk
Revenue by country of domicile:
Concentration risk	2.00%	3.00%	0.00%	6.00%