Deposits and Other Current Assets - Deposits and Other Current Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Deposits:
Deposits for research and development, prototype parts and other	$ 27,106	$ 28,609
Deposits for goods and services yet to be received (“Future Work”)	2,760	2,773
Total deposits	29,866	31,382
Other current assets:
Prepaid expenses	6,255	13,309
Other current assets	8,935	8,412
Total other current assets	$ 15,190	$ 21,721