Business Acquisition - Summary of intangible assets acquired (Details) $ in Thousands	3 Months Ended
Mar. 31, 2023 USD ($)
Business Acquisition
Impairment of intangible assets	$ 4,600
Aceragen
Business Acquisition
Acquisition Date Fair Value	71,600
Aceragen \| In-process research and development costs (IPR&D)
Business Acquisition
Acquisition Date Fair Value	71,600
Impairment of intangible assets	(4,600)
Carrying Value	67,000
Aceragen \| ACG-701 for Cystic Fibrosis
Business Acquisition
Acquisition Date Fair Value	50,700
Impairment of intangible assets	(2,600)
Carrying Value	48,100
Aceragen \| ACG-701 for Melioidosis
Business Acquisition
Acquisition Date Fair Value	14,900
Carrying Value	14,900
Aceragen \| ACG-801 for Farber Disease
Business Acquisition
Acquisition Date Fair Value	6,000
Impairment of intangible assets	(2,000)
Carrying Value	$ 4,000

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- Definition

Amount of assets, excluding financial assets and goodwill, that lack physical substance, having a projected indefinite period of benefit, acquired at the acquisition date.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=128092470&loc=d3e4845-128472

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- Definition

Amount of impairment loss resulting from write-down of assets, excluding financial assets and goodwill, lacking physical substance and having a projected indefinite period of benefit to fair value.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 3
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=66006027&loc=d3e16373-109275

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-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

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Amount of assets, excluding financial assets and goodwill, lacking physical substance and having a projected indefinite period of benefit.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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-Topic 350
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