SEGMENT REPORTING (Segment Financial Disclosure) (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Total revenues	[1]	$ 1,068,344	$ 1,049,242
Gross profit		229,267	201,723
Depreciation, Depletion, Accretion & Amortization (DDA&A)		100,368	95,480
Cash and cash equivalents and restricted cash		890,939	120,273	$ 1,198,013	$ 274,506
Total assets		11,332,760	10,629,382	$ 11,686,905
Operating Segments [Member]
Segment Reporting Information [Line Items]
Total revenues	[1]	1,125,495	1,104,806
Total assets		10,313,537	10,362,404
Intersegment Sales [Member]
Segment Reporting Information [Line Items]
Total revenues	[1]	(57,151)	(55,564)
Aggregates [Member]
Segment Reporting Information [Line Items]
Total revenues	[1]	837,758	812,662
Aggregates [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total revenues	[1],[2]	894,909	868,226
Gross profit		223,638	194,131
Depreciation, Depletion, Accretion & Amortization (DDA&A)		80,808	77,136
Total assets	[3]	9,438,411	9,473,128
Aggregates [Member] | Intersegment Sales [Member]
Segment Reporting Information [Line Items]
Total revenues	[1]	(57,151)	(55,564)
Asphalt [Member]
Segment Reporting Information [Line Items]
Total revenues	[1]	147,167	139,789
Asphalt [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total revenues	[1],[4]	147,167	139,789
Gross profit		(2,991)	(2,435)
Depreciation, Depletion, Accretion & Amortization (DDA&A)		9,095	8,734
Total assets	[3]	563,961	563,630
Asphalt [Member] | Intersegment Sales [Member]
Segment Reporting Information [Line Items]
Total revenues	[1]	0	0
Concrete [Member]
Segment Reporting Information [Line Items]
Total revenues	[1]	81,359	94,765
Concrete [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total revenues	[1]	81,359	94,765
Gross profit		7,768	9,213
Depreciation, Depletion, Accretion & Amortization (DDA&A)		3,952	4,082
Total assets	[3]	307,718	322,044
Concrete [Member] | Intersegment Sales [Member]
Segment Reporting Information [Line Items]
Total revenues	[1]	0	0
Calcium [Member]
Segment Reporting Information [Line Items]
Total revenues	[1]	2,060	2,026
Calcium [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total revenues	[1]	2,060	2,026
Gross profit		852	814
Depreciation, Depletion, Accretion & Amortization (DDA&A)		39	49
Total assets	[3]	3,447	3,602
Calcium [Member] | Intersegment Sales [Member]
Segment Reporting Information [Line Items]
Total revenues	[1]	0	0
Other Segments [Member]
Segment Reporting Information [Line Items]
Depreciation, Depletion, Accretion & Amortization (DDA&A)		6,474	5,479
Corporate [Member]
Segment Reporting Information [Line Items]
Total assets		$ 128,284	$ 146,705

[1] ¹ The geographic markets are defined by states/countries as follows: East market — Arkansas, Delaware, Illinois, Kentucky, Maryland, North Carolina, Pennsylvania, Tennessee, Virginia, and Washington D.C. Gulf Coast market — Alabama, Florida, Georgia, Louisiana, Mexico, Mississippi, Oklahoma, South Carolina and Texas West market — Arizona, California and New Mexico

[2] Includes product sales (crushed stone, sand and gravel, sand, and other aggregates), as well as freight & delivery costs that we pass along to our customers, and service revenues (see Note 4) related to aggregates.

[3] Certain temporarily idled assets are included within a segment's Identifiable Assets but the associated DDA&A is shown within Other in the DDA&A section above as the related DDA&A is excluded from segment gross profit.

[4] Includes product sales, as well as service revenues (see Note 4) from our asphalt construction paving business.