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Stock-Based Compensation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands			1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 11, 2025	Nov. 21, 2024	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025	Dec. 31, 2025	Aug. 26, 2026	Oct. 27, 2025	Nov. 08, 2024
Share-based Compensation Plans
Shares reserved for issuance				17,015,625		17,015,625
Stock-based compensation expense				$ 15,232	$ 209	$ 17,420	$ 245
Accrued expenses and other current liabilities				28,791		28,791		$ 12,313
Accrued other liabilities, non-current				376		376		$ 538
Location, Statement of Income, Balance [Axis]: us-gaap:GeneralAndAdministrativeExpense
Share-based Compensation Plans
Stock-based compensation expense				1,749	0	2,707	0
Location, Statement of Income, Balance [Axis]: us-gaap:ResearchAndDevelopmentExpense
Share-based Compensation Plans
Stock-based compensation expense				$ 13,483	209	$ 14,713	$ 245
2025 Equity Incentive Plan
Share-based Compensation Plans
Shares available for grant				0		0
2026 Stock Incentive Plan
Share-based Compensation Plans
Initial shares authorized				6,092,348		6,092,348
Shares available for grant				5,898,568		5,898,568
Shares increase percentage						5.00%
2026 Employee Stock Purchase Plan
Share-based Compensation Plans
Shares available for grant				2,000,000		2,000,000
Shares increase percentage						1.00%
Shares reserved for issuance									550,512
Employee Stock Option
Share-based Compensation Plans
Weighted average grant date fair value						$ 6.74
Granted (in shares)						5,752,553	0
Unrecognized compensation cost, recognition period (in years)						3 years 4 months 24 days
Unrecognized compensation cost, options				$ 34,500		$ 34,500
Stock-based compensation expense				2,533	0	$ 3,807	$ 0
Employee Stock Option \| 2025 Equity Incentive Plan
Share-based Compensation Plans
Award vesting period						4 years
Award expiration period						10 years
Restricted Stock Awards
Share-based Compensation Plans
Shares available for grant											1,037,000
Share price											$ 0.1
Unrecognized compensation cost, recognition period (in years)						2 years 8 months 12 days
Unrecognized compensation cost, options				400		$ 400
Stock-based compensation expense				35	10	105	46
Percentage of vesting	60.00%	40.00%
Reclassified from liability to equity				100		300
Restricted Stock Awards \| Parasa Holding LLC
Share-based Compensation Plans
Shares available for grant											518,500
Restricted Stock Awards \| Maximum
Share-based Compensation Plans
Stock-based compensation expense				100	100	$ 100	100
Restricted Stock Awards \| 2025 Equity Incentive Plan \| Chief Executive Officer
Share-based Compensation Plans
Shares available for grant										207,400
Parasa Warrant Obligation
Share-based Compensation Plans
Award expiration period								10 years
Unrecognized compensation cost, recognition period (in years)						3 months 18 days
Unrecognized compensation cost, options				4,600		$ 4,600
Stock-based compensation expense				$ 12,664	199	$ 13,508	199
Share outstanding percentage			1.00%
Fair value of the warrant obligation								$ 800
Warrants purchase for common stock								228,671
Exercise price per share								$ 4.15
Parasa Warrant Obligation \| Location, Statement of Income, Balance [Axis]: us-gaap:ResearchAndDevelopmentExpense
Share-based Compensation Plans
Stock-based compensation expense					$ 200		$ 200