Significant Accounting Policies - Additional Information (Details) $ in Millions	12 Months Ended
	Dec. 31, 2025 USD ($) Segment	Dec. 31, 2024 USD ($)
Defined Contribution Plan Disclosure [Line Items]
Defined contribution plan, cost \| $	$ 0.4	$ 0.4
Number of operating segment \| Segment	1
Segment Reporting, CODM, Individual Title and Position or Group Name [Extensible Enumeration]	srt:ChiefExecutiveOfficerMember
Segment Reporting, CODM, Profit (Loss) Measure, How Used, Description	The Company’s Chief Operating Decision Maker ("CODM"), its chief executive officer, assesses performance for the Company’s one operating segment and allocates resources based on net loss, consistent with what is reported on the statements of operations and comprehensive loss. The CODM also assesses the performance of the Company’s one operating segment by using operating expenses to monitor budget versus actual results.
Defined Contribution Plan, Employer Matching Contribution, First Tier
Defined Contribution Plan Disclosure [Line Items]
Defined contribution plan, employer matching contribution, percent of employees' gross pay	3.00%
Defined contribution plan, employer matching contribution, percent of match	100.00%
Defined Contribution Plan, Employer Matching Contribution, Second Tier
Defined Contribution Plan Disclosure [Line Items]
Defined contribution plan, employer matching contribution, percent of employees' gross pay	2.00%
Defined contribution plan, employer matching contribution, percent of match	50.00%

SERA PROGNOSTICS, INC. 10-K