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Subsequent Events (Details) $ / shares in Units, $ in Millions	Feb. 06, 2025 USD ($) $ / shares	Mar. 25, 2025 USD ($)	Dec. 31, 2024 $ / shares	Jun. 30, 2024 $ / shares	Dec. 31, 2023 $ / shares
Voting common stock
Subsequent Events
Common stock, par or stated value per share | $ / shares			$ 0.0001	$ 0.0001	$ 0.0001
Subsequent Event
Subsequent Events
Termination fee	$ 10.0
Subsequent Event | Kaken
Subsequent Events
Upfront, non-refundable payment		$ 20.0
Payment to global development cost		20.0
Aggregate payment of regulatory and commercial milestones		$ 140.0
Subsequent Event | The Combined Company
Subsequent Events
Ownership percentage	55.00%
Subsequent Event | ACELYRIN
Subsequent Events
Common stock, par or stated value per share | $ / shares	$ 0.00001
Termination fee	$ 10.0
Subsequent Event | ACELYRIN | The Combined Company
Subsequent Events
Ownership percentage	45.00%
Subsequent Event | ACELYRIN | Voting common stock
Subsequent Events
Cancelled and converted Ratio	0.4274

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- Definition

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- Definition

Face amount or stated value per share of common stock.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

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Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 830
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481674/830-30-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 855
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
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-Publisher FASB
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