v3.25.4

Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Income Tax Disclosure [Line Items]
Current income tax benefits	$ 0	$ 0	$ 0
Deferred income tax benefits	$ 0	0	0
Operating losses carried forward, expiration date	2035
Operating loss carryforwards, federal	$ 425,000,000
Percentage of net operating loss carry forward deductible from current year taxable income	80.00%
Federal orphan drug tax credits	$ 37,100,000
Federal orphan drug credit carry forwards expiration year	2041
Annual limitation amount per year under section 382	$ 300,000
Unrecognized tax benefits	0	$ 0	$ 0
Provision for income taxes	0
Income tax payments	0
U.S. federal [Member]
Income Tax Disclosure [Line Items]
Net operating losses carryforwards	428,300,000
Research and development tax credits carryforwards	$ 28,800,000
Tax credit carryforwards, expiration year	2040
Net operating losses subject to limitation under section 382	$ 73,000,000.0
State [Member]
Income Tax Disclosure [Line Items]
Net operating losses carryforwards	170,800,000
Research and development tax credits carryforwards	$ 6,000,000
Tax credit carryforwards, expiration year	2035
Net operating losses subject to limitation under section 382	$ 1,500,000

Annual limitation amount per year under section 382.

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Income Tax Disclosure [Line Items]

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Amount of current income tax expense (benefit) pertaining to taxable income (loss) from continuing operations.

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Cogent Biosciences, Inc. 10-K