Organization and Basis of Presentation - Summary of Reverse Recapitalization (Details) - USD ($) $ in Thousands		12 Months Ended
	Dec. 30, 2021	Dec. 31, 2021	Dec. 31, 2020
Schedule Of Reverse Recapitalization [Line Items]
Cash - PIPE Investment	$ 165,000
Cash - Athena Trust Account, net of redemptions and cash on hand	22,848
Net proceeds from Business Combination and PIPE financing	159,400	$ 159,400	$ 0
Less: Accrued transaction costs	(1,474)	(1,474)	0
Add: Prepaid expenses and receivables assumed as part of Business Combination	1,651
Less: Warrants assumed as part of Business Combination	(10,880)	$ (10,880)	$ 0
Less: Accounts payable assumed as part of Business Combination	(498)
Reverse recapitalization and PIPE financing, net	148,199
Athena Public Stockholders
Schedule Of Reverse Recapitalization [Line Items]
Less transaction costs and advisory fees paid	(16,186)
Heliogen Stockholders
Schedule Of Reverse Recapitalization [Line Items]
Less transaction costs and advisory fees paid	$ (12,262)