GOODWILL (Changes in Carrying Amount of Goodwill by Reportable Segment) (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2019 USD ($)
Goodwill [Line Items]
Goodwill, Beginning balance	$ 3,165,396
Goodwill of acquired businesses	1,665	[1]
Goodwill, Ending balance	3,167,061
Aggregates [Member]
Goodwill [Line Items]
Goodwill, Beginning balance	3,073,763
Goodwill of acquired businesses	1,665	[1]
Goodwill, Ending balance	3,075,428
Asphalt [Member]
Goodwill [Line Items]
Goodwill, Beginning balance	91,633
Goodwill of acquired businesses	0	[1]
Goodwill, Ending balance	91,633
Concrete [Member]
Goodwill [Line Items]
Goodwill, Beginning balance	0
Goodwill of acquired businesses	0	[1]
Goodwill, Ending balance	0
Calcium [Member]
Goodwill [Line Items]
Goodwill, Beginning balance	0
Goodwill of acquired businesses	0	[1]
Goodwill, Ending balance	$ 0

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