Significant Components of Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets:
Net operating loss carryforwards	$ 150,523	$ 141,176
Research and development credit carryforwards	29,411	28,892
Capitalized research and development	8,406	10,756
Compensation related items	11,951	10,957
Operating leases	4,125	4,214
Other	8,218	6,051
Total deferred tax assets	212,634	202,046
Valuation allowance	(209,524)	(199,042)
Net deferred tax assets	3,110	3,004
Deferred tax liabilities:
Right-of-use assets	2,895	2,892
Other	313	163
Total deferred tax liabilities	$ 3,208	$ 3,055