ACQUISITIONS AND DIVESTITURES (Narrative) (Details)		3 Months Ended					12 Months Ended
		Mar. 31, 2015 USD ($)	Mar. 31, 2014 USD ($)	Sep. 30, 2013 USD ($)	Jun. 30, 2013 USD ($) property	Mar. 31, 2013 USD ($) property	Dec. 31, 2015 USD ($) property	Dec. 31, 2014 USD ($) property item shares		Dec. 31, 2013 USD ($)
Significant Acquisitions and Disposals [Line Items]
Proceeds from sale of property, plant & equipment				$ 11,261,000			$ 8,218,000	$ 26,028,000		$ 17,576,000
Total consideration							47,198,000	331,836,000
Payment for acquisition of businesses							27,198,000	284,237,000		89,951,000
Exchanges of real property and businesses							20,000,000	2,414,000
Cash paid							27,198,000
Amortizable intangible assets recognized								128,286,000
Goodwill							0	13,303,000	[1]
Proceeds from sale of businesses, net of transaction costs					$ 34,743,000	$ 5,133,000	0	721,359,000		51,604,000
Gain on sale of properties and businesses				9,027,000	21,183,000	2,802,000	9,927,000	244,222,000		39,250,000
Purchases of property, plant & equipment							289,262,000	224,852,000		275,380,000
Capital gains with deferred income taxes							665,057,000	661,697,000
Consideration transferred, common stock							$ 0	$ 45,185,000		0
Common stock issued in connection with business acquisitions | shares								715,004
Goodwill of dispositions					4,521,000	$ 674,000				5,195,000	[1]
Withdrawl liability					$ 4,000,000
Aggregates [Member]
Significant Acquisitions and Disposals [Line Items]
Number of facilities divested | property					4	1
Goodwill	[1]							$ 13,303,000
Goodwill of dispositions	[1]									5,195,000
Aggregates [Member] | Arizona and New Mexico [Member]
Significant Acquisitions and Disposals [Line Items]
Number of facilities acquired | property							3
Aggregates [Member] | Maryland [Member]
Significant Acquisitions and Disposals [Line Items]
Proceeds from sale of property, plant & equipment			$ 10,727,000
Gain on sale of properties and businesses			168,000
Aggregates [Member] | Tennessee [Member]
Significant Acquisitions and Disposals [Line Items]
Proceeds from sale of property, plant & equipment			5,820,000
Gain on sale of properties and businesses			5,790,000
Concrete [Member]
Significant Acquisitions and Disposals [Line Items]
Goodwill	[1]							0
Goodwill of dispositions	[1]									0
Concrete [Member] | Arizona and New Mexico [Member]
Significant Acquisitions and Disposals [Line Items]
Number of facilities acquired | property							7
Asphalt Mix [Member]
Significant Acquisitions and Disposals [Line Items]
Goodwill	[1]							0
Goodwill of dispositions	[1]									$ 0
Asphalt Mix [Member] | Arizona [Member]
Significant Acquisitions and Disposals [Line Items]
Number of facilities acquired | property							13
Cement And Concrete [Member]
Significant Acquisitions and Disposals [Line Items]
Proceeds from sale of businesses, net of transaction costs			721,359,000
Gain on sale of properties and businesses			$ 227,910,000					227,910,000
Supply agreement period			20 years
Contractual Rights In Place [Member]
Significant Acquisitions and Disposals [Line Items]
Amortizable intangible assets recognized								$ 36,921,000
Estimated weighted-average amortization period of intangible assets								40 years
Intangible assets amortization period, tax purposes							15 years	15 years
Unit Of Production Method [Member] | Aggregates and Concrete [Member] | Arizona and New Mexico [Member]
Significant Acquisitions and Disposals [Line Items]
Amortizable intangible assets recognized							$ 10,317,000
Estimated weighted-average amortization period of intangible assets							34 years
Straight Line Method [Member] | Asphalt Mix [Member] | Arizona [Member]
Significant Acquisitions and Disposals [Line Items]
Amortizable intangible assets recognized							$ 7,168,000
Estimated weighted-average amortization period of intangible assets							20 years
California ready-mixed concrete operations [Member] | California [Member]
Significant Acquisitions and Disposals [Line Items]
Number of facilities divested | property							12
Gain on sale of properties and businesses		$ 5,886,000
Asphalt plants and Aggregates facilities [Member] | Asphalt And Aggregates [Member] | California [Member]
Significant Acquisitions and Disposals [Line Items]
Number of facilities acquired | property								2
Aggregates sites [Member] | Aggregates [Member] | California [Member]
Significant Acquisitions and Disposals [Line Items]
Number of facilities acquired | property								4
Aggregates sites [Member] | Aggregates [Member] | Arizona and New Mexico [Member]
Significant Acquisitions and Disposals [Line Items]
Number of facilities acquired | property								5
Aggregates sites [Member] | Aggregates [Member] | Delaware [Member]
Significant Acquisitions and Disposals [Line Items]
Number of facilities acquired | property								2
Rail-connected aggregates operation [Member] | Dallas/Fort Worth [Member]
Significant Acquisitions and Disposals [Line Items]
Number of facilities acquired | item								1
Permitted aggregates quarry [Member] | Alabama [Member]
Significant Acquisitions and Disposals [Line Items]
Number of facilities acquired | item								1
Distribution yards [Member] | Dallas/Fort Worth [Member]
Significant Acquisitions and Disposals [Line Items]
Number of distribution yard acquired | property								2
Volumetric production payment (VPP) [Member]
Significant Acquisitions and Disposals [Line Items]
Gross proceeds from sale of future production				154,000,000
Business Acquisition, Transaction Costs				$ 905,000

[1] Refer to Note 19 for additional details.