SEGMENT REPORTING (Segment Financial Disclosure) (Details) $ in Thousands		1 Months Ended	3 Months Ended		6 Months Ended
		Jan. 31, 2015 property	Jun. 30, 2015 USD ($)	Jun. 30, 2014 USD ($)	Jun. 30, 2015 USD ($)	Jun. 30, 2014 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Segment Reporting Information [Line Items]
Total revenues			$ 895,143	$ 791,143	$ 1,526,436	$ 1,365,563
Gross profit			234,449	174,788	312,314	208,881
Depreciation, depletion, accretion and amortization			68,384	68,323	135,108	137,702
Cash items			74,736	227,684	74,736	227,684	$ 141,273	$ 193,738
Total assets			8,195,883	7,910,838	8,195,883	7,910,838	$ 8,041,097
Number of asphalt mix plants | property		13
Identifiable assets [Member]
Segment Reporting Information [Line Items]
Total assets	[1]		8,007,500	7,596,000	8,007,500	7,596,000
Segment sales [Member]
Segment Reporting Information [Line Items]
Total revenues			943,400	834,200	1,611,600	1,461,300
Aggregates [Member]
Segment Reporting Information [Line Items]
Gross profit	[2]		207,300	161,700	275,000	200,200
Depreciation, depletion, accretion and amortization	[2]		57,000	56,300	112,500	111,000
Aggregates [Member] | Identifiable assets [Member]
Segment Reporting Information [Line Items]
Total assets	[1],[2]		7,497,200	7,126,400	7,497,200	7,126,400
Aggregates [Member] | Segment sales [Member]
Segment Reporting Information [Line Items]
Total revenues	[2]		733,400	628,900	1,236,900	1,057,600
Aggregates [Member] | Intersegment sales [Member]
Segment Reporting Information [Line Items]
Total revenues			(48,300)	(43,100)	(85,200)	(86,500)
Asphalt Mix [Member]
Segment Reporting Information [Line Items]
Gross profit	[3]		21,100	9,000	29,900	13,700
Depreciation, depletion, accretion and amortization	[3]		4,100	2,400	8,000	4,800
Asphalt Mix [Member] | Identifiable assets [Member]
Segment Reporting Information [Line Items]
Total assets	[1],[3]		319,300	224,900	319,300	224,900
Asphalt Mix [Member] | Segment sales [Member]
Segment Reporting Information [Line Items]
Total revenues	[3]		129,000	109,300	232,100	193,600
Concrete [Member]
Segment Reporting Information [Line Items]
Gross profit	[3],[4]		4,900	3,200	5,700	(6,000)
Depreciation, depletion, accretion and amortization	[3],[4]		2,800	4,800	5,500	10,800
Concrete [Member] | Identifiable assets [Member]
Segment Reporting Information [Line Items]
Total assets	[1],[3],[4]		185,500	238,700	185,500	238,700
Concrete [Member] | Segment sales [Member]
Segment Reporting Information [Line Items]
Total revenues	[3],[4]		78,600	93,800	138,400	189,800
Calcium [Member]
Segment Reporting Information [Line Items]
Gross profit	[5]		1,100	900	1,700	1,000
Depreciation, depletion, accretion and amortization	[5]		200	200	300	1,200
Calcium [Member] | Identifiable assets [Member]
Segment Reporting Information [Line Items]
Total assets	[1],[5]		5,500	6,000	5,500	6,000
Calcium [Member] | Segment sales [Member]
Segment Reporting Information [Line Items]
Total revenues	[5]		2,400	2,200	4,200	20,300
Calcium [Member] | Intersegment sales [Member]
Segment Reporting Information [Line Items]
Total revenues			0	0	0	(9,200)
Other [Member]
Segment Reporting Information [Line Items]
Depreciation, depletion, accretion and amortization			4,300	4,600	8,800	9,900
Corporate [Member]
Segment Reporting Information [Line Items]
Total assets			$ 113,700	$ 87,100	$ 113,700	$ 87,100

[1] 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.

[2] Includes crushed stone, sand and gravel, sand, other aggregates, as well as freight, delivery and transportation revenues, and other revenues related to services.

[3] In January 2015, we exchanged our California ready-mixed concrete operations for 13 asphalt mix plants, primarily in Arizona (see Note 16).

[4] Includes ready-mixed concrete. In March 2014, we sold our concrete business in the Florida area (see Note 16) which in addition to ready-mixed concrete, included concrete block, precast concrete, as well as building materials purchased for resale.

[5] Includes cement and calcium products. In March 2014, we sold our cement business (see Note 16).