Fair Value Measurements - Summary of Fair Value of the Sponsor Warrants Associated with the Liability (Detail) - Fair Value, Inputs, Level 3 [Member] $ in Billions	Sep. 30, 2026 USD ($) yr	Dec. 31, 2025 USD ($) yr
Volatility [member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Sponsor Warrants	0.25	0.25
Probability of Not Completing a Deal [member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Sponsor Warrants	0.30	0.30
Expected Time to Complete a Deal (in years) [member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Sponsor Warrants | yr	3.5	3.9
Probability of Warrant Renegotiation [member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Sponsor Warrants	0.30	0.30
Estimated Target Equity Value [member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Estimated Target Equity Value | $	$ 4.5	$ 4.5