ACQUISITIONS AND DIVESTITURES (Narrative) (Details)			3 Months Ended			6 Months Ended		12 Months Ended
		Aug. 26, 2021 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)	Mar. 31, 2021 USD ($)	Jun. 30, 2022 USD ($) item	Jun. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)
Significant Acquisitions and Disposals [Line Items]
Goodwill	[1]					$ 45,700,000
Gain on sale of property, plant & equipment and businesses			$ 2,000,000.0	$ 200,000		4,600,000	$ 117,400,000
Amount of assets divested			0			0
Assets held for sale			0	$ 0		0	$ 0	$ 0
Acquisitions 2022 [Member]
Significant Acquisitions and Disposals [Line Items]
Total consideration						233,500,000
Amortizable intangible assets recognized						$ 41,300,000
Estimated weighted-average amortization period of intangible assets						16 years
Intangible assets amortization period, tax purposes						15 years
Goodwill						$ 0.0
Intangible assets, deductible for income tax purposes			$ 41,300,000			41,300,000
Acquisitions 2021 [Member]
Significant Acquisitions and Disposals [Line Items]
Amortizable intangible assets recognized								685,500,000
Goodwill								570,300,000
Goodwill, deductible for income tax purposes								108,500,000
U.S. Concrete, Inc. [Member]
Significant Acquisitions and Disposals [Line Items]
Total consideration		$ 1,634,500,000				1,634,500,000
Goodwill						570,300,000
Changes in carrying amount of goodwill						45,700,000
California [Member]
Significant Acquisitions and Disposals [Line Items]
Consideration transferred, net of assets divested					$ 12,900,000
Gain on sale of property, plant & equipment and businesses					$ 114,700,000
California [Member] | Immaterial Business Acquisitions [Member]
Significant Acquisitions and Disposals [Line Items]
Total consideration								$ 4,900,000
Aggregates [Member]
Significant Acquisitions and Disposals [Line Items]
Goodwill	[1]					$ 1,300,000
Aggregates [Member] | Texas [Member]
Significant Acquisitions and Disposals [Line Items]
Number of facilities acquired | item						5
Aggregates [Member] | Texas [Member] | Production Stage Properties [Member]
Significant Acquisitions and Disposals [Line Items]
Number of facilities acquired | item						3
Aggregates [Member] | Texas [Member] | Development Stage Property [Member]
Significant Acquisitions and Disposals [Line Items]
Number of facilities acquired | item						1
Aggregates [Member] | Texas [Member] | Aggregate Sales Yard [Member]
Significant Acquisitions and Disposals [Line Items]
Number of facilities acquired | item						1
Ready-Mixed Concrete Facilities [Member] | Virginia [Member]
Significant Acquisitions and Disposals [Line Items]
Number of facilities acquired | item						4
Idle Ready-Mixed Concrete Sites [Member] | Virginia [Member]
Significant Acquisitions and Disposals [Line Items]
Number of facilities acquired | item						2
Amortizable Intangible Asset Straight-Line Method [Member] | Acquisitions 2021 [Member]
Significant Acquisitions and Disposals [Line Items]
Estimated weighted-average amortization period of intangible assets						15 years

[1] See Note 16 for acquisitions