Segments - Financial Data for Continuing Operations for Company's Reportable Business Segments (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Segment Reporting Information [Line Items]
Total Revenues	$ 1,354.1	$ 1,230.8
Earnings (Loss) from operations	196.1	59.9
Building Materials Business
Segment Reporting Information [Line Items]
Total Revenues	1,270.7	1,153.8
Earnings (Loss) from operations	203.6	71.0
Operating Segments | Building Materials Business East Group
Segment Reporting Information [Line Items]
Total Revenues	529.6	418.8
Earnings (Loss) from operations	108.9	28.0
Operating Segments | Building Materials Business West Group
Segment Reporting Information [Line Items]
Total Revenues	741.1	735.0
Earnings (Loss) from operations	94.7	43.0
Operating Segments | Magnesia Specialties
Segment Reporting Information [Line Items]
Total Revenues	83.4	77.0
Earnings (Loss) from operations	20.6	21.5
Operating Segments | Building Materials Business
Segment Reporting Information [Line Items]
Total Revenues	1,270.7	1,153.8
Corporate
Segment Reporting Information [Line Items]
Earnings (Loss) from operations	$ (28.1)	$ (32.6)