Fair Value Measurements - Additional Information (Details) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2025 USD ($) yr	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short-term investments in held-to-maturity securities, at amortized cost	$ 782.7		$ 412.9
Short-term investments in held-to-maturity securities, gross unrealized gain	$ 0.2		$ 0.2
Measurement Input, Price Volatility
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Earnout liability, measurement input	0.20
Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Treasury bills, maturity period	3 months	3 months
Minimum | Measurement Input, Risk Free Interest Rate
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Earnout liability, measurement input	0.036
Minimum | Measurement Input, Expected Term
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Earnout liability, measurement input | yr	0.13
Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Treasury bills, maturity period	12 months	12 months
Maximum | Measurement Input, Risk Free Interest Rate
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Earnout liability, measurement input	0.041
Maximum | Measurement Input, Expected Term
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Earnout liability, measurement input | yr	3.13
Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Highly liquid money market funds	$ 0.2	$ 0.3
Short-term investments in held-to-maturity securities, at amortized cost, excluding accrued interest	782.5	412.7
Short-term investments in held-to-maturity securities, gross accrued interest	$ 7.5	$ 4.3