Revenues and Gross Profit - Total Revenues and Gross Profit (Loss) by Product Line (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Product Information [Line Items]
Total Revenues	$ 1,354.1	$ 1,230.8
Gross profit (loss)	302.8	156.1
Interproduct Revenues
Product Information [Line Items]
Total Revenues	(87.8)	(89.0)
Corporate
Product Information [Line Items]
Gross profit (loss)	1.9	(7.9)
Building Materials Business
Product Information [Line Items]
Total Revenues	1,270.7	1,153.8
Building Materials Business | Operating Segments
Product Information [Line Items]
Total Revenues	1,270.7	1,153.8
Gross profit (loss)	275.9	138.4
Magnesia Specialties | Operating Segments
Product Information [Line Items]
Total Revenues	83.4	77.0
Gross profit (loss)	25.0	25.6
Aggregates | Building Materials Business | Operating Segments | Reportable Subsegments
Product Information [Line Items]
Total Revenues	911.9	756.6
Gross profit (loss)	238.1	102.8
Cement | Building Materials Business | Operating Segments | Reportable Subsegments
Product Information [Line Items]
Total Revenues	168.6	138.3
Gross profit (loss)	47.1	26.9
Ready Mixed Concrete | Building Materials Business | Operating Segments | Reportable Subsegments
Product Information [Line Items]
Total Revenues	220.0	291.1
Gross profit (loss)	11.2	21.9
Asphalt and Paving | Building Materials Business | Operating Segments | Reportable Subsegments
Product Information [Line Items]
Total Revenues	58.0	56.8
Gross profit (loss)	$ (20.5)	$ (13.2)