Fair Value Measurements - Narrative (Details) - USD ($) $ in Thousands		9 Months Ended
	Jun. 22, 2023	Sep. 30, 2025
CVR liability
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Change in fair value of liability, decrease		$ 42,199
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