Gross Amounts and Dates of Expiration of Tax Credits and Carryovers (Detail) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Income Tax Disclosure [Line Items]
Federal losses carryovers	$ 590,870
California loss carryovers	104,900
Other state loss carryovers	44,257
Research credits	28,567	$ 29,242
Federal foreign tax credits	610
Federal
Income Tax Disclosure [Line Items]
Research credits	16,758
California
Income Tax Disclosure [Line Items]
Research credits	14,948
Expires 2024-2026
Income Tax Disclosure [Line Items]
Federal losses carryovers	60,190
Other state loss carryovers	115
Expires 2024-2026 | Federal
Income Tax Disclosure [Line Items]
Research credits	1,403
Expires 2027-2033
Income Tax Disclosure [Line Items]
Federal losses carryovers	191,075
California loss carryovers	67,161
Other state loss carryovers	1,685
Federal foreign tax credits	610
Expires 2027-2033 | Federal
Income Tax Disclosure [Line Items]
Research credits	1,808
Expires 2034-2043
Income Tax Disclosure [Line Items]
Federal losses carryovers	148,686
California loss carryovers	37,739
Other state loss carryovers	31,503
Expires 2034-2043 | Federal
Income Tax Disclosure [Line Items]
Research credits	13,547
No Expiration
Income Tax Disclosure [Line Items]
Federal losses carryovers	190,919
Other state loss carryovers	10,954
No Expiration | California
Income Tax Disclosure [Line Items]
Research credits	$ 14,948