Investments of Insurance Subsidiaries - Schedule of Investments (Detail) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Debt Securities, Available-for-sale [Line Items]
Amounts classified as current assets	$ (105)	$ (103)
Investment carrying value	408	438
Amortized Cost	523	525
Unrealized Amounts, Gains	4	18
Unrealized Amounts, Losses	(14)	(2)
Fair Value	513	541
Money Market Funds and Other [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	112	125
Fair Value	112	125
Debt Securities [Member] \| States and Municipalities [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	411	400
Unrealized Amounts, Gains	4	18
Unrealized Amounts, Losses	(14)	(2)
Fair Value	$ 401	$ 416

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