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- Definition

Notes Receivable Percentage

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- Definition

Share Based Compensation Arrangement Description

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- Definition

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

+ References

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- Definition

Amount of expense for employee benefit and equity-based compensation.

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- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

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- Definition

The aggregate total of expenses of managing and administering the affairs of an entity, including affiliates of the reporting entity, which are not directly or indirectly associated with the manufacture, sale or creation of a product or product line.

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- Definition

Including the current and noncurrent portions, aggregate carrying amount of all types of notes payable, as of the balance sheet date, with initial maturities beyond one year or beyond the normal operating cycle, if longer.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Per share or per unit amount of equity securities issued.

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No definition available.

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Number of shares issued in lieu of cash for services contributed to the entity. Number of shares includes, but is not limited to, shares issued for services contributed by vendors and founders.

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No definition available.

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Number of new stock issued during the period.

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Related Party Transactions - Additional Information (Detail) $ / shares in Units, $ in Thousands	1 Months Ended			12 Months Ended
	Sep. 30, 2025 shares	Aug. 31, 2025 $ / shares shares	Feb. 28, 2025 $ / shares shares	Dec. 31, 2025 USD ($) shares	Dec. 31, 2024 USD ($) shares	Dec. 31, 2025 € / shares	Nov. 30, 2025 USD ($)
Related Party Transaction [Line Items]
General and administrative expense				$ 65,088	$ 47,544
Share Based Compensation Arrangement Description				In June 2025, the Company granted to Mr. Angermayer in further consideration of his continued service as a consultant and other valuable consideration (i) an option to purchase 337,686 shares of common stock of the Company that will vest with respect to 131,698 shares subject to the option based on the Company’s standard four year vesting schedule and with respect to 205,988 shares subject to the option based on the Company achieving certain asset value goals by December 31, 2026 and continued service with the Company through such date, and (ii) an option to purchase 292,500 shares that will vest based on Company achieving certain asset value goals by December 31, 2026 and continued service with the Company through such date.
Share price \| € / shares						€ 0.1
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount \| shares				68,304,083	53,870,211
Founder [Member] \| Atai Formation [Member]
Related Party Transaction [Line Items]
Equity method investment, ownership percentage				15.20%	20.10%
Apeiron [Member]
Related Party Transaction [Line Items]
Issuance of common shares, net of issuance costs ,Shares \| shares		8,675,799	10,835,718
Share price \| $ / shares		$ 2.19	$ 2.1
Apeiron [Member] \| Promissory Note Agreement [Member]
Related Party Transaction [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount \| shares	2,367,200
Mr Angermayer [Member]
Related Party Transaction [Line Items]
General and administrative expense				$ 100	$ 300
Mr Angermayer [Member] \| Consulting Agreement [Member] \| General and Administrative Expense [Member]
Related Party Transaction [Line Items]
Stock-based compensation				$ 900	$ 400
Feilding Mellen [Member]
Related Party Transaction [Line Items]
Stock issued during period, Shares, Issued for services \| shares				10,000
Feilding Mellen [Member] \| General and Administrative Expense [Member]
Related Party Transaction [Line Items]
Stock-based compensation				$ 100
Beckley Psytech [Member]
Related Party Transaction [Line Items]
Promissory note				$ 10,000
Amandala Neuro Limited Notes Receivable [Member]
Related Party Transaction [Line Items]
Notes receivable							$ 1,500
Notes Receivable Percentage							33.70%