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+ References

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+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 3
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-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 45
-Paragraph 1
-Subparagraph (a)
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Net cash outflow or inflow from monetary allowance granted by the landlord to a tenant to entice tenant to move into landlords building which will enable the tenant to prepare the leased premises for tenants occupancy.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
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The amount of an asset, typically cash, provided to a counterparty to provide certain assurance of performance by the entity pursuant to the terms of a written or oral agreement, such as a lease.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
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Leases - Additional Information (Detail) - USD ($)			3 Months Ended
Leases - Additional Information (Detail) - USD ($)	Aug. 11, 2021	Aug. 16, 2019	Mar. 31, 2022	Dec. 31, 2021
Lessee Lease Description [Line Items]
Monthly base rent	$ 377,000,000		$ 200,000
Increase in base rent	388,000		33,000
Annual increase of base rent			9,000
Security deposit			500,000
Tenant Allowance	430,000
Operating Lease, Right-of-Use Asset	$ 7,000,000.0		19,286,000	$ 20,054,000
Hampshire Street [Member] \| Letter of Credit [Member]
Lessee Lease Description [Line Items]
Security deposit			$ 1,000,000.0	$ 1,000,000.0
Operating lease extend description	the Company extended the term of the Technology Square Lease through November 30, 2024
BMR-Hampshire LLC [Member] \| Cambridge [Member]
Lessee Lease Description [Line Items]
Operating lease description		the Company entered into a lease (the "Hampshire Street Lease") with BMR-Hampshire LLC ("BMR"). The Hampshire Street Lease is for 33,525 rentable square feet of office space in Cambridge, Massachusetts. The Hampshire Street Lease commenced as of December 1, 2019
Operating lease extend description		the Company with an option to extend the lease term for one additional five-year period
Operating lease rent expense		$ 200,000
Operating lease rent expense incremental percentage		2.50%