Fair Values on Financial Assets and Liabilities (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Fair value of financial assets and liabilities
Total financial assets	$ 81,662	$ 88,340
Money market funds
Fair value of financial assets and liabilities
Total short-term investments	11,187	7,170
Short-term Investments
Fair value of financial assets and liabilities
Total short-term investments	81,372	87,770
United States government agency securities \| Short-term Investments
Fair value of financial assets and liabilities
Total short-term investments	20,251	25,685
Corporate debt securities \| Short-term Investments
Fair value of financial assets and liabilities
Total short-term investments	47,543	52,560
Mortgage-backed securities \| Short-term Investments
Fair value of financial assets and liabilities
Total short-term investments	2,391	2,355
Warrant \| Other Assets
Fair value of financial assets and liabilities
Warrants	290	570
Level 1
Fair value of financial assets and liabilities
Total financial assets	11,187	7,170
Level 1 \| Money market funds
Fair value of financial assets and liabilities
Total short-term investments	11,187	7,170
Level 1 \| Short-term Investments
Fair value of financial assets and liabilities
Total short-term investments	11,187	7,170
Level 2
Fair value of financial assets and liabilities
Total financial assets	70,185	80,600
Level 2 \| Short-term Investments
Fair value of financial assets and liabilities
Total short-term investments	70,185	80,600
Level 2 \| United States government agency securities \| Short-term Investments
Fair value of financial assets and liabilities
Total short-term investments	20,251	25,685
Level 2 \| Corporate debt securities \| Short-term Investments
Fair value of financial assets and liabilities
Total short-term investments	47,543	52,560
Level 2 \| Mortgage-backed securities \| Short-term Investments
Fair value of financial assets and liabilities
Total short-term investments	2,391	2,355
Level 3
Fair value of financial assets and liabilities
Total financial assets	290	570
Level 3 \| Warrant \| Other Assets
Fair value of financial assets and liabilities
Warrants	$ 290	$ 570

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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+ References

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-Publisher FASB
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Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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