Indebtedness - Schedule of Net Carrying Amount of 2027 Notes (Details) - 2027 Notes - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Debt Instrument [Line Items]
Principal amount	$ 200,000	$ 200,000
Unamortized debt discount	(1,633)	(2,321)
Unamortized debt issuance cost	(110)	(156)
Net carrying amount	$ 198,257	$ 197,523

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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+ Details

- Definition

Amount, after deduction of unamortized premium (discount) and debt issuance cost, of long-term debt. Excludes lease obligation.

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Gossamer Bio, Inc. 10-Q