v3.25.2
Subsequent Events - Additional Information (Details)
3 Months Ended 6 Months Ended
Jul. 08, 2025
SquareFeet
Sep. 30, 2025
USD ($)
Jun. 30, 2025
USD ($)
Jun. 30, 2024
USD ($)
Jun. 30, 2025
USD ($)
Jun. 30, 2024
USD ($)
Jul. 17, 2025
USD ($)
Subsequent Event [Line Items]              
Net loss     $ 114,698,000 $ 122,953,000 $ 229,121,000 $ 243,581,000  
Subsequent Event | Maximum | PowerCo              
Subsequent Event [Line Items]              
Potential funding contribution amount             $ 130,700,000
QuantumScape Battery, Inc. | Lease Termination Agreement | Forecast | Maximum              
Subsequent Event [Line Items]              
Net loss   $ 10,000,000          
QuantumScape Battery, Inc. | Lease Termination Agreement | Subsequent Event              
Subsequent Event [Line Items]              
Area of rentable space lease | SquareFeet 80,641            
Lease termination date Aug. 01, 2025            
Lease expiration date Sep. 30, 2032