Fair Value Measurements - Narrative (Details) - USD ($) $ in Thousands		9 Months Ended
Jun. 22, 2023	Sep. 30, 2026
CVR liability
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Decrease in fair value of contingent value rights liability		$ 19,900
Payments		55,733
Changes in the fair value of the CVR liability		$ 35,813
Spyre Therapeutics, Inc.
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset acquisition, stockholder payment period (in years)	3 years
Asset acquisition, cash payment, threshold period (in years)	1 year

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Amount of gain (loss) recognized in income from liability measured at fair value on recurring basis using unobservable input (level 3).

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Amount of increase (decrease) of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of settlements of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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