Income Taxes - Additional Information (Detail) - USD ($)	1 Months Ended		12 Months Ended
	Jun. 30, 2024	Aug. 31, 2004	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Taxes [Line Items]
Valuation allowance of deferred tax assets			$ 694,369,000	$ 698,228,000	$ 705,034,000	$ 695,094,000
Valuation allowance			(3,859,000)	(6,806,000)	9,940,000
Federal operating loss carryforwards			1,900,000,000
State operating loss carryforwards			1,300,000,000
Federal operation loss carryforwards, not subject to expiration			$ 492,900,000
Deferred tax assets, operating loss carryforwards, begin to expire			2026
Operating loss carryforwards, limitations on use			Pursuant to IRC Sections 382 and 383, annual use of the Company’s federal and California net operating loss and research and development credit carryforwards may be limited in the event a cumulative change in ownership of more than 50% occurs within a three-year period.
Net operating loss carryforwards		$ 105,800,000
Net operating loss and credit carryforwards, annual use limitation		$ 13,000,000
Tax credit carryforwards research and development credits federal			$ 53,700,000
Tax credit carryforwards research and development credits state			22,100,000
Unrecognized income tax interest and penalties			$ 0	$ 0	$ 0
Federal
Income Taxes [Line Items]
Research and development credits begin to expire			2025
Senate Bills 167 | California
Income Taxes [Line Items]
Net operating losses	$ 5,000,000
Tax years	2024 2025 2026
Senate Bills 175 | California
Income Taxes [Line Items]
Tax years	2025 2026