Overview (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2024 USD ($) segment	Mar. 31, 2023 USD ($)	Dec. 31, 2023 USD ($)	Aug. 31, 2023 USD ($)
Line of Credit Facility [Line Items]
Number of operating segments | segment	1
Number of reportable segments | segment	1
Net loss	$ 46,708	$ 71,600
Net cash used in operating activities	40,474	30,478
Accumulated deficit	922,554		$ 875,846
Cash and cash equivalents	31,773	$ 16,127	$ 69,473
Working capital	22,097
Outstanding debt	$ 3,458
DOE Clean Energy Financing Program | Notes Payable
Line of Credit Facility [Line Items]
Aggregate principal amount				$ 398,600