Fair Value Measurement - Schedule of Significant Unobservable Inputs (Level 3) and the Change in Fair Value (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2025	Dec. 31, 2024
Common Stock Warrant Liability
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value, beginning balance	$ 20,835	$ 4,440
Change in fair value	34,586	16,395
Fair value, ending balance	55,421	20,835
Term Loan Derivative Liability
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value, beginning balance	0	903
Change in fair value		222
(Derecognition) recognition		(1,125)
Fair value, ending balance		0
2025 Convertible Notes Derivative Liability
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value, beginning balance	0
Recognition in connection with convertible notes offering	31,900
Change in fair value	(7,311)
(Derecognition) recognition	(24,589)
Fair value, ending balance	$ 0	$ 0