Segments - Financial Data for Continuing Operations for Company's Reportable Business Segments (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Segment Reporting Information [Line Items]
Revenues	$ 1,764	$ 1,821	$ 3,015	$ 3,175
Earnings from Operations	398	463	1,819	659
Interest expense	40	42	80	84
Other nonoperating income, net	(14)	(19)	(46)	(35)
Consolidated earnings from continuing operations before income tax expense	372	440	1,785	610
Assets employed	16,333		16,333		$ 15,125
Reportable segments
Segment Reporting Information [Line Items]
Earnings from Operations	445	490	1,896	714
Assets employed	15,464		15,464		13,078
Operating Segments | East Group
Segment Reporting Information [Line Items]
Revenues	823	735	1,349	1,265
Earnings from Operations	249	227	378	337
Assets employed	7,687		7,687		5,131
Operating Segments | West Group
Segment Reporting Information [Line Items]
Revenues	860	1,005	1,505	1,746
Earnings from Operations	171	240	1,470	334
Assets employed	7,516		7,516		7,697
Operating Segments | Magnesia Specialties
Segment Reporting Information [Line Items]
Revenues	81	81	161	164
Earnings from Operations	25	23	48	43
Assets employed	261		261		250
Corporate
Segment Reporting Information [Line Items]
Earnings from Operations	(47)	$ (27)	(77)	$ (55)
Assets employed	$ 869		$ 869		$ 2,047