ACQUISITIONS AND DIVESTITURES (Narrative) (Details) - USD ($)		3 Months Ended				9 Months Ended		12 Months Ended
	Aug. 26, 2021	Sep. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Significant Acquisitions and Disposals [Line Items]
Cash						$ 1,634,492,000	$ 5,668,000
Goodwill						502,651,000
Gain on sale of property, plant & equipment and businesses		$ 2,940,000			$ 1,576,000	120,316,000	2,317,000
Assets held for sale		0		$ 0	$ 0	0	$ 0	$ 0
Acquisitions 2021 [Member]
Significant Acquisitions and Disposals [Line Items]
Amortizable intangible assets recognized						729,415,000
Goodwill						502,651,000
Goodwill, deductible for income tax purposes		$ 116,615,000				116,615,000
Acquisitions 2020 [Member]
Significant Acquisitions and Disposals [Line Items]
Total consideration								73,416,000
Cash								43,223,000
Consideration payable amount								30,193,000
Amortizable intangible assets recognized								$ 65,545,000
Intangible assets amortization period, tax purposes								15 years
Goodwill								$ 5,051,000
Intangible assets, deductible for income tax purposes				$ 25,712,000				25,712,000
U.S. Concrete, Inc. [Member]
Significant Acquisitions and Disposals [Line Items]
Total consideration	$ 1,634,492,000
Cash	1,268,507,000
Cash	1,634,492,000
Goodwill	502,651,000
Deferred income taxes, net	$ 274,226,000
U.S. Concrete, Inc. [Member] | Acquisition-related Costs [Member]
Significant Acquisitions and Disposals [Line Items]
Supplemental Pro Forma Results, Net earnings attributable to Vulcan						21,092,000
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			$ 114,695,000
New Mexico [Member]
Significant Acquisitions and Disposals [Line Items]
Supply agreement period					20 years
Virginia [Member]
Significant Acquisitions and Disposals [Line Items]
Supply agreement period				20 years
Aggregates [Member]
Significant Acquisitions and Disposals [Line Items]
Goodwill						$ 185,981,000
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
Amortizable Intangible Asset Straight-Line Method [Member] | Acquisitions 2020 [Member]
Significant Acquisitions and Disposals [Line Items]
Amortizable intangible assets recognized								$ 65,545,000
Estimated weighted-average amortization period of intangible assets								20 years