Equity Method Investment - Schedule of Ownership Interest (Details) - Gannet BioChem - shares	6 Months Ended	12 Months Ended
Jun. 30, 2026	Dec. 31, 2025
Schedule of Equity Method Investments [Line Items]
Common units owned by Nektar	20,000,000	20,000,000
Percentage ownership of common units outstanding	89.00%	100.00%
Percentage ownership of common and preferred units outstanding	19.00%	20.00%

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