ACQUISITIONS AND DIVESTITURES (Narrative) (Details) - USD ($)		3 Months Ended				12 Months Ended
		Mar. 31, 2018		Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2017
Significant Acquisitions and Disposals [Line Items]
Consideration transferred, net of assets divested						$ 842,013,000
Total consideration		$ 76,559,000				1,080,815,000
Cash consideration		76,259,000			$ 185,067,000	822,432,000
Consideration payable amount						9,681,000
Assets acquired				$ 9,900,000		9,900,000
Goodwill		7,840,000	[1]			27,497,000
Proceeds from sale of property, plant & equipment		1,701,000			1,239,000
Gain on sale of property, plant & equipment and businesses		4,164,000			369,000
Assets held for sale		$ 0		0	$ 0	0
Aggregates USA [Member]
Significant Acquisitions and Disposals [Line Items]
Amount of assets divested				287,292,000		287,292,000
Gain on sale of property, plant & equipment and businesses				0
Acquisitions 2017 [Member]
Significant Acquisitions and Disposals [Line Items]
Amortizable intangible assets recognized						309,112,000
Intangible assets amortization period, tax purposes		15 years
Arizona [Member]
Significant Acquisitions and Disposals [Line Items]
Gain on sale of property, plant & equipment and businesses				8,021,000
Assets divested, fair value				9,900,000		9,900,000
Assets held for sale				$ 1,879,000		1,879,000
Georgia [Member]
Significant Acquisitions and Disposals [Line Items]
Gain on sale of property, plant & equipment and businesses		$ 2,929,000
Aggregates [Member]
Significant Acquisitions and Disposals [Line Items]
Goodwill	[1]	7,840,000
Concrete [Member]
Significant Acquisitions and Disposals [Line Items]
Goodwill	[1]	0
Asphalt [Member]
Significant Acquisitions and Disposals [Line Items]
Goodwill	[1]	$ 0
Contractual Rights In Place [Member] | Acquisitions 2017 [Member]
Significant Acquisitions and Disposals [Line Items]
Amortizable intangible assets recognized						309,012,000
Contractual Rights In Place - Straight-Line Method [Member] | Acquisitions 2017 [Member]
Significant Acquisitions and Disposals [Line Items]
Amortizable intangible assets recognized						73,879,000
Estimated weighted-average amortization period of intangible assets		19 years 3 months 18 days
Contractual Rights In Place - Units Of Sales [Member] | Acquisitions 2017 [Member]
Significant Acquisitions and Disposals [Line Items]
Amortizable intangible assets recognized						235,133,000
Estimated weighted-average amortization period of intangible assets		54 years 8 months 12 days
Other Intangibles [Member] | Acquisitions 2017 [Member]
Significant Acquisitions and Disposals [Line Items]
Amortizable intangible assets recognized						$ 100,000

[1] See Note 16 for a summary of acquisitions.