Commitments and Contingencies (Details) $ in Thousands				1 Months Ended	9 Months Ended	12 Months Ended
	Jan. 17, 2025 respondent	Apr. 19, 2024 USD ($)	Aug. 22, 2023 respondent	Jun. 30, 2024 USD ($)	Sep. 30, 2025 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2024 USD ($)	Aug. 19, 2024 USD ($)	Apr. 01, 2024 patent	Mar. 28, 2024 patent	Mar. 19, 2024 patent	Aug. 25, 2023 director entity	Mar. 19, 2021 director entity
Loss Contingencies [Line Items]
Outstanding letter of credit					$ 1,400		$ 1,400
Insurance receivable					0		$ 2,000
Settled Litigation
Loss Contingencies [Line Items]
Respondents dismissed | respondent	3		2
Nick v. Velodyne Lidar, Inc., et al.
Loss Contingencies [Line Items]
Number of directors filed against | director													2
Number of other entities filed against in lawsuits | entity													3
Moradpour v. Velodyne Lidar, Inc., et al.
Loss Contingencies [Line Items]
Settlement amount awarded to other party		$ 27,500
Estimated funds from insurance proceeds		$ 23,400
Litigation liability accrued						$ 27,500
Insurance receivable						23,400		$ 23,400
Settlement expense				$ 4,100		$ 4,100
Payments for legal settlements				$ 4,100
Berger v. Graf Acquisition, LLC, et al.
Loss Contingencies [Line Items]
Number of directors filed against | director												6
Number of other entities filed against in lawsuits | entity												2
Hesai Photonic vs. Velodyne Legacy
Loss Contingencies [Line Items]
Litigation liability accrued					$ 11,800
Hesai Photonics
Loss Contingencies [Line Items]
Number of patents under review | patent									4	4	4