Income Taxes - Reconciliation of Beginning and Ending Amount of Unrecognized Tax Benefits (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Federal, State and Local Tax [Member]
Reconciliation Of Unrecognized Tax Benefits [Line Items]
Beginning Balance	$ 30	$ 38	$ 49
Increases as a result of tax positions taken in prior years	5
Decreases as a result of tax positions taken in prior years	(13)	(11)	(11)
Unrecognized tax benefits assumed in a business combination		3
Ending Balance	22	30	38
Accrued Interest [Member]
Reconciliation Of Unrecognized Tax Benefits [Line Items]
Beginning Balance	8	8	8
Increases as a result of tax positions taken in prior years	1	3	3
Decreases as a result of tax positions taken in prior years	(3)	(4)	(3)
Unrecognized tax benefits assumed in a business combination		1
Ending Balance	6	8	8
Unrecognized Income Tax Benefits [Member]
Reconciliation Of Unrecognized Tax Benefits [Line Items]
Beginning Balance	38	45	56
Increases as a result of tax positions taken in prior years	6	3	3
Decreases as a result of tax positions taken in prior years	(16)	(15)	(14)
Unrecognized tax benefits assumed in a business combination		5
Ending Balance	28	$ 38	$ 45
Less: Federal, state and local income tax benefits	(6)
Net unrecognized tax benefits that, if recognized, would impact the effective income tax rate	$ 22