Segments - Financial Data for Continuing Operations for Company's Reportable Business Segments (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Segment Reporting Information [Line Items]
Revenues	$ 1,889	$ 1,994	$ 4,905	$ 5,169
Earnings from Operations	489	567	2,308	1,226
Interest expense	38	41	119	125
Other nonoperating income, net	(7)	(14)	(54)	(49)
Consolidated earnings from continuing operations before income tax expense	458	540	2,243	1,150
Assets employed	16,469		16,469		$ 15,125
Reportable segments
Segment Reporting Information [Line Items]
Earnings from Operations	531	595	2,426	1,310
Assets employed	15,645		15,645		13,078
Operating Segments | East Group
Segment Reporting Information [Line Items]
Revenues	849	814	2,198	2,079
Earnings from Operations	272	295	650	632
Assets employed	7,667		7,667		5,131
Operating Segments | West Group
Segment Reporting Information [Line Items]
Revenues	958	1,104	2,464	2,851
Earnings from Operations	233	283	1,703	617
Assets employed	7,713		7,713		7,697
Operating Segments | Magnesia Specialties
Segment Reporting Information [Line Items]
Revenues	82	76	243	239
Earnings from Operations	26	17	73	61
Assets employed	265		265		250
Corporate
Segment Reporting Information [Line Items]
Earnings from Operations	(42)	$ (28)	(118)	$ (84)
Assets employed	$ 824		$ 824		$ 2,047