Segments - Financial Data for Continuing Operations for Company's Reportable Segments (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Total revenues	$ 4,739.1	$ 4,244.3	$ 3,965.6
Gross profit	1,179.0	966.6	971.9
Selling, general and administrative expenses	302.7	280.6	262.1
Earnings (Loss) from operations	884.9	690.7	700.4
Assets employed	10,131.6	9,551.4	8,992.5
Depreciation, depletion and amortization	371.5	344.0	297.2
Total property additions, including the impact of acquisitions	387.6	1,925.6	438.6
Property additions through acquisitions		1,543.2	2.5
Building Materials Business
Segment Reporting Information [Line Items]
Total revenues	4,467.8	3,956.6	3,695.6
Gross profit	1,080.6	860.3	875.6
Selling, general and administrative expenses	201.0	182.1	173.7
Earnings (Loss) from operations	894.2	690.8	706.6
Assets employed	9,642.5	9,077.6	7,163.4
Depreciation, depletion and amortization	341.3	315.7	270.3
Total property additions, including the impact of acquisitions	355.6	1,908.3	414.9
Property additions through acquisitions		1,543.2	2.5
Operating Segments \| Building Materials Business Mid-America Group
Segment Reporting Information [Line Items]
Total revenues	1,446.0	1,223.2	1,053.3
Gross profit	482.9	366.9	335.4
Selling, general and administrative expenses	63.1	55.8	53.9
Earnings (Loss) from operations	425.9	319.1	284.8
Assets employed	2,879.3	2,788.5	1,532.9
Depreciation, depletion and amortization	110.2	93.6	69.7
Total property additions, including the impact of acquisitions	127.7	1,157.1	139.5
Property additions through acquisitions		980.3	0.1
Operating Segments \| Building Materials Business Southeast Group
Segment Reporting Information [Line Items]
Total revenues	506.4	423.4	362.6
Gross profit	124.1	77.2	74.6
Selling, general and administrative expenses	21.6	18.7	17.1
Earnings (Loss) from operations	103.1	75.9	61.2
Assets employed	1,442.5	1,299.5	616.3
Depreciation, depletion and amortization	47.8	41.2	30.8
Total property additions, including the impact of acquisitions	45.3	603.1	34.6
Property additions through acquisitions		561.5
Operating Segments \| Building Materials Business West Group
Segment Reporting Information [Line Items]
Total revenues	2,515.4	2,310.0	2,279.7
Gross profit	473.6	416.2	465.6
Selling, general and administrative expenses	116.3	107.6	102.7
Earnings (Loss) from operations	365.2	295.8	360.6
Assets employed	5,320.7	4,989.6	5,014.2
Depreciation, depletion and amortization	183.3	180.9	169.8
Total property additions, including the impact of acquisitions	182.6	148.1	240.8
Property additions through acquisitions		1.4	2.4
Operating Segments \| Building Materials Business
Segment Reporting Information [Line Items]
Total revenues	4,467.8	3,956.6	3,695.6
Gross profit	1,080.6	860.3	875.6
Operating Segments \| Magnesia Specialties
Segment Reporting Information [Line Items]
Total revenues	271.3	287.7	270.0
Gross profit	95.4	98.7	89.4
Selling, general and administrative expenses	11.3	10.0	9.5
Earnings (Loss) from operations	83.6	88.1	79.4
Assets employed	176.2	156.1	152.3
Depreciation, depletion and amortization	10.2	10.4	10.1
Total property additions, including the impact of acquisitions	20.0	12.5	11.1
Corporate
Segment Reporting Information [Line Items]
Gross profit	3.0	7.6	6.9
Selling, general and administrative expenses	90.4	88.5	78.9
Earnings (Loss) from operations	(92.9)	(88.2)	(85.6)
Assets employed	312.9	317.7	1,676.8
Depreciation, depletion and amortization	20.0	17.9	16.8
Total property additions, including the impact of acquisitions	$ 12.0	$ 4.8	$ 12.6

Property, plant and equipment, additions through acquisitions.

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Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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Aggregate revenue less cost of goods and services sold or operating expenses directly attributable to the revenue generation activity.

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Amount of acquisition of long-lived, physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

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Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

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