Commitments and Contingencies - Imsidolimab - Narrative (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended
	Jan. 31, 2025	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Commitments and Contingencies [Line Items]
Research and development		$ 22,563	$ 16,776	$ 80,265	$ 54,591
Imsidolimab
Commitments and Contingencies [Line Items]
Development and milestone obligations paid to third party	$ 10,000
Additional development and milestone payments to third party	$ 5,000
Research and development				14,400
Royalty payable percentage on net sales	10.00%
Imsidolimab \| Future Regulatory Approval and Sales Milestones
Commitments and Contingencies [Line Items]
Possible future milestone payment				35,000
Imsidolimab \| Future Regulatory Approval, Filing Application For Marketing Authorization Milestone \| U.S.
Commitments and Contingencies [Line Items]
Possible future milestone payment				5,000
Imsidolimab \| Future Regulatory Approval, Filing Application For Marketing Authorization Milestone \| E.U.
Commitments and Contingencies [Line Items]
Possible future milestone payment				5,000
Imsidolimab \| Future Regulatory Approval, Sales Milestones
Commitments and Contingencies [Line Items]
Possible future milestone payment				25,000
Collaborative Arrangement, Transaction with Party to Collaborative Arrangement
Commitments and Contingencies [Line Items]
Research and development				$ 2,700

Vanda Pharmaceuticals Inc. 10-Q