v3.25.4
Fair Value Measurements - Summary of Fair Value of Financial Instruments (Details) - USD ($)
$ in Thousands
Sep. 30, 2025
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Schedule Of Fair Value Liabilities Measured On Non Recurring Basis [Line Items]        
Warrant liabilities $ 0 $ 112 $ 163 $ 1,103
Common stock warrants        
Schedule Of Fair Value Liabilities Measured On Non Recurring Basis [Line Items]        
Warrant liabilities   45 64 218
Preferred stock warrants        
Schedule Of Fair Value Liabilities Measured On Non Recurring Basis [Line Items]        
Warrant liabilities   67 99 $ 885
Quoted Prices In Active Markets for Identical Assets Level 1        
Schedule Of Fair Value Liabilities Measured On Non Recurring Basis [Line Items]        
Warrant liabilities   0 0  
Quoted Prices In Active Markets for Identical Assets Level 1 | Common stock warrants        
Schedule Of Fair Value Liabilities Measured On Non Recurring Basis [Line Items]        
Warrant liabilities   0 0  
Quoted Prices In Active Markets for Identical Assets Level 1 | Preferred stock warrants        
Schedule Of Fair Value Liabilities Measured On Non Recurring Basis [Line Items]        
Warrant liabilities   0 0  
Significant Other Observable Inputs Level 2        
Schedule Of Fair Value Liabilities Measured On Non Recurring Basis [Line Items]        
Warrant liabilities   0 0  
Significant Other Observable Inputs Level 2 | Common stock warrants        
Schedule Of Fair Value Liabilities Measured On Non Recurring Basis [Line Items]        
Warrant liabilities   0 0  
Significant Other Observable Inputs Level 2 | Preferred stock warrants        
Schedule Of Fair Value Liabilities Measured On Non Recurring Basis [Line Items]        
Warrant liabilities   0 0  
Significant Unobservable Inputs Level 3        
Schedule Of Fair Value Liabilities Measured On Non Recurring Basis [Line Items]        
Warrant liabilities   112 163  
Significant Unobservable Inputs Level 3 | Common stock warrants        
Schedule Of Fair Value Liabilities Measured On Non Recurring Basis [Line Items]        
Warrant liabilities   45 64  
Significant Unobservable Inputs Level 3 | Preferred stock warrants        
Schedule Of Fair Value Liabilities Measured On Non Recurring Basis [Line Items]        
Warrant liabilities   $ 67 $ 99