Prepaid Expenses and Other Current Assets (Detail) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Deposit for fuel cell components (Note 15)	$ 4,443	$ 6,092
Vehicle inventory deposits	357	2,074
Production equipment deposits	141	235
Other prepaid expenses	1,473	1,877
Prepaid insurance	641	3,201
VAT receivable from government	1,487	1,886
Total prepaid expenses and other current assets	$ 8,542	$ 15,365