Balance Sheet Components - Prepaid and Other Current Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Prepaid and Other Current Assets
Interest receivable	$ 45	$ 32
Prepaid research and development manufacturing expenses	192	740
Prepaid facility expenses	182	174
Prepaid insurance	252	280
Other	102	128
Total of prepaid and other current assets	$ 773	$ 1,354

Amount of asset related to consideration paid in advance for facility expenses.

No definition available.

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Balance Type:	debit
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- Definition

Amount of asset related to consideration paid in advance for research and development expense that provides economic benefits within a future period of one year or the normal operating cycle, if longer.

+ References

No definition available.

+ Details

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- Definition

Carrying amount as of the balance sheet date of interest earned but not received. Also called accrued interest or accrued interest receivable.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(3)(a)(4))
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+ Details

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- Definition

Amount of current assets classified as other.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(8))
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- Definition

Amount of asset related to consideration paid in advance for costs that provide economic benefits in future periods, and amount of other assets that are expected to be realized or consumed within one year or the normal operating cycle, if longer.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(9))
-URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

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- References

No definition available.

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Amount of asset related to consideration paid in advance for insurance that provides economic benefits within a future period of one year or the normal operating cycle, if longer.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 340
-SubTopic 10
-Section 45
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=6387103&loc=d3e6435-108320

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+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant