Restructuring Charges - Addition Information (Detail) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended	6 Months Ended
Apr. 30, 2022	Jun. 30, 2022	Jun. 30, 2022
Restructuring Costs [Abstract]
Number of headcount reduced, percentage	35.00%
Restructuring charges related to severance payment and other employee-related costs		$ 1,520	$ 1,520
Restructuring charges were paid		728	728
Remaining accrued restructuring charges to be paid in next six months		$ 792	$ 792

Remaining accrued restructuring charges to be paid in next six months.

No definition available.

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Namespace Prefix:	sldb_
Data Type:	xbrli:monetaryItemType
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Period Type:	instant

- Definition

Amount of cash payments made as the result of exit or disposal activities. Excludes payments associated with a discontinued operation or an asset retirement obligation.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-URI https://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 17
-Subparagraph (f)
-URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3367-108585

+ Details

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Balance Type:	credit
Period Type:	duration

- Definition

The number of positions eliminated during the period as a percentage of total positions eliminated during the period in connection with the restructuring plan(s).

+ References

No definition available.

+ Details

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Period Type:	duration

- References

No definition available.

+ Details

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Data Type:	xbrli:stringItemType
Balance Type:	na
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- Definition

Amount of expenses for special or contractual termination benefits provided to current employees involuntarily terminated under a benefit arrangement associated exit or disposal activities pursuant to an authorized plan. Excludes expenses related to one-time termination benefits, a discontinued operation or an asset retirement obligation.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3602-108585

+ Details

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