Segments - Financial Data for Continuing Operations for Company's Reportable Business Segments (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Segment Reporting Information [Line Items]
Assets employed	$ 18,170	$ 15,125
Total property additions, including the impact of acquisitions	4,455	626	$ 544
Property additions through acquisitions	3,585	0	3
Reportable Segments
Segment Reporting Information [Line Items]
Assets employed	16,662	13,078
Total property additions, including the impact of acquisitions	4,433	612	523
Operating Segments | East Group
Segment Reporting Information [Line Items]
Assets employed	8,452	5,131
Total property additions, including the impact of acquisitions	3,185	231	189
Property additions through acquisitions	2,853	0	0
Operating Segments | West Group
Segment Reporting Information [Line Items]
Assets employed	7,941	7,697
Total property additions, including the impact of acquisitions	1,216	342	302
Property additions through acquisitions	732	0	3
Operating Segments | Magnesia Specialties
Segment Reporting Information [Line Items]
Assets employed	269	250
Total property additions, including the impact of acquisitions	32	39	32
Corporate
Segment Reporting Information [Line Items]
Assets employed	1,508	2,047
Total property additions, including the impact of acquisitions	$ 22	$ 14	$ 21