Investments of Insurance Subsidiaries - Schedule of Maturities of Investments (Detail) $ in Millions	Dec. 31, 2023 USD ($)
Investments, Debt and Equity Securities [Abstract]
Due in one year or less, Amortized Cost	$ 12
Due after one year through five years, Amortized Cost	150
Due after five years through ten years, Amortized Cost	165
Due after ten years, Amortized Cost	77
Amortized Cost, Total	404
Due in one year or less, Fair Value	12
Due after one year through five years, Fair Value	144
Due after five years through ten years, Fair Value	148
Due after ten years, Fair Value	72
Fair Value, Total	$ 376