Reconciliation of Statutory Federal Income Tax (benefit) Rate to Company's Effective Tax Rate (Detail)	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Tax at statutory federal rate	(21.00%)	(21.00%)
State Tax (benefit)—net of federal benefit	(0.00%)	(0.00%)
Permanent differences	0.35%	0.58%
Tax credits	(5.86%)	(12.26%)
Derecognition due to Sec. 382 and 383 limitations	(0.00%)	44.55%
Change in valuation allowance	26.26%	(12.25%)
Other	0.25%	0.38%
Effective tax rate	0.00%	0.00%

Effective income tax rate reconciliation derecognition.

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Effective income tax rate reconciliation, permanent differences.

+ References

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Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32687-109319

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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to changes in the valuation allowance for deferred tax assets.

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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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-Name Accounting Standards Codification
-Topic 740
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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations applicable to state and local income tax expense (benefit), net of federal tax expense (benefit).

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to tax credits. Including, but not limited to, research credit, foreign tax credit, investment tax credit, and other tax credits.

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