Revenues and Gross Profit - Total Revenues and Gross Profit (Loss) by Product Line (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Product Information [Line Items]
Total Revenues	$ 1,811.7	$ 1,557.3	$ 4,684.2	$ 3,917.6
Gross profit (loss)	487.8	441.9	1,069.1	1,001.7
Interproduct Revenues
Product Information [Line Items]
Total Revenues	(104.6)	(115.3)	(295.0)	(285.1)
Corporate
Product Information [Line Items]
Gross profit (loss)	(2.1)	0.5	(8.5)	0.3
Building Materials Business
Product Information [Line Items]
Total Revenues	1,736.0	1,478.9	4,449.8	3,692.6
Building Materials Business | Operating Segments
Product Information [Line Items]
Total Revenues	1,736.0	1,478.9	4,449.8	3,692.6
Gross profit (loss)	469.3	414.4	1,006.7	920.0
Building Materials Business | Operating Segments | Products and Services
Product Information [Line Items]
Total Revenues	1,611.5	1,390.8	4,137.7	3,472.8
Gross profit (loss)	467.2	413.1	1,005.0	918.3
Magnesia Specialties | Operating Segments
Product Information [Line Items]
Total Revenues	75.7	78.4	234.4	225.0
Gross profit (loss)	20.6	27.0	70.9	81.4
Magnesia Specialties | Operating Segments | Products
Product Information [Line Items]
Total Revenues	69.0	71.9	214.4	207.1
Gross profit (loss)	21.6	28.1	74.3	84.4
Aggregates | Building Materials Business | Operating Segments | Reportable Subsegments | Products and Services
Product Information [Line Items]
Total Revenues	1,015.7	857.1	2,656.8	2,231.5
Gross profit (loss)	330.3	292.9	741.2	687.7
Cement | Building Materials Business | Operating Segments | Reportable Subsegments | Products and Services
Product Information [Line Items]
Total Revenues	163.2	132.3	455.4	358.4
Gross profit (loss)	67.7	49.9	146.1	101.3
Ready Mixed Concrete | Building Materials Business | Operating Segments | Reportable Subsegments | Products and Services
Product Information [Line Items]
Total Revenues	227.4	320.8	743.6	824.5
Gross profit (loss)	18.7	31.4	54.1	69.9
Asphalt and Paving | Building Materials Business | Operating Segments | Reportable Subsegments | Products and Services
Product Information [Line Items]
Total Revenues	309.8	195.9	576.9	343.5
Gross profit (loss)	50.5	38.9	63.6	59.4
Freight
Product Information [Line Items]
Total Revenues	131.2	94.6	332.1	237.7
Freight | Building Materials Business
Product Information [Line Items]
Total Revenues	124.5	88.1	312.1	219.8
Freight | Building Materials Business | Operating Segments
Product Information [Line Items]
Total Revenues	124.5	88.1	312.1	219.8
Gross profit (loss)	2.1	1.3	1.7	1.7
Freight | Magnesia Specialties | Operating Segments
Product Information [Line Items]
Total Revenues	6.7	6.5	20.0	17.9
Gross profit (loss)	$ (1.0)	$ (1.1)	$ (3.4)	$ (3.0)