Variable Interest Entities (Detail) - USD ($) $ in Millions	Mar. 31, 2025	Dec. 31, 2024
Variable Interest Entity
Carrying value of debt	$ 23,837	$ 23,900
Assets	44,486	44,567
Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity
Assets	131	128
Low income housing investments [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity
Aggregate investment balance	684	707
Carrying value of debt	655	670
Trust For Final Capping, Closure, Post-closure Or Environmental Remediation Obligations [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity
Aggregate investment balance	$ 111	$ 111