Commitments and Contingencies - Schedule of Maturity Analysis of Annual Undiscounted Cash Flows of Operating and Finance Lease Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Commitments And Contingencies Disclosure [Abstract]
Operating Leases, 2021	$ 136
Operating Leases, 2022	120
Operating Leases, 2023	75
Operating Leases, 2024	6
Operating Leases, 2025
Total lease payments	337
Operating Leases, Less imputed interest	23
Operating Leases, Total	314	$ 430
Finance Leases, 2021	44
Finance Leases, 2022	39
Finance Leases, 2023	39
Finance Leases, 2024	39
Finance Leases, 2025	39
Total lease payments	200
Finance Leases, Less imputed interest	15
Finance Leases, Total	$ 185	$ 54

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Present value of lessee's discounted obligation for lease payments from finance lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=121609121&loc=SL77918701-209980

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 45
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121603541&loc=SL77918627-209977

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 45
-Paragraph 1
-Subparagraph (b)
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