Asset Acquisition - Additional Information (Details) $ / shares in Units, $ in Millions	Jun. 22, 2023 USD ($) $ / shares shares
Asset Acquisition [Line Items]
Cost to acquire asset | $	$ 113.3
Asset Acquisition
Asset Acquisition [Line Items]
Asset acquisition consideration transferred issuable shares of common stock on an as-converted basis	364,887,000
Spyre 2023 Equity Incentive Plan | Asset Acquisition
Asset Acquisition [Line Items]
Outstanding and unexercised stock options	68,365
Series A Preferred Stock | Asset Acquisition
Asset Acquisition [Line Items]
Asset acquisition consideration transferred equity interest issued, shares	364,887
Shares issued, price per share | $ / shares	$ 291.08
Common Stock | Asset Acquisition
Asset Acquisition [Line Items]
Asset acquisition consideration transferred equity interest issued, shares	12,945,385
Shares issued, price per share | $ / shares	$ 0.29108