SEGMENT REPORTING (Segment Financial Disclosure) (Details) (USD $) In Thousands, unless otherwise specified	1 Months Ended	3 Months Ended
	Jan. 31, 2015 property	Mar. 31, 2015		Mar. 31, 2014		Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Total revenues		$ 631,293		$ 574,420
Gross profit		77,865		34,092
Depreciation, depletion, accretion and amortization		66,723		69,378
Cash items		392,657		268,773		141,273	193,738
Total assets		8,350,615		7,872,235		8,061,902
Number of asphalt mix plants	13
Identifiable assets [Member]
Segment Reporting Information [Line Items]
Total assets		7,835,200	[1]	7,484,600	[1]
Segment sales [Member]
Segment Reporting Information [Line Items]
Total revenues		668,200		627,100
Aggregates [Member]
Segment Reporting Information [Line Items]
Gross profit		67,700	[2]	38,500	[2]
Depreciation, depletion, accretion and amortization		55,500	[2]	54,600	[2]
Aggregates [Member] | Identifiable assets [Member]
Segment Reporting Information [Line Items]
Total assets		7,331,700	[1],[2]	7,004,200	[1],[2]
Aggregates [Member] | Segment sales [Member]
Segment Reporting Information [Line Items]
Total revenues		503,500	[2]	428,700	[2]
Aggregates [Member] | Intersegment sales [Member]
Segment Reporting Information [Line Items]
Total revenues		(36,900)		(43,500)
Asphalt Mix [Member]
Segment Reporting Information [Line Items]
Gross profit		8,800	[3]	4,700	[3]
Depreciation, depletion, accretion and amortization		3,900	[3]	2,400	[3]
Asphalt Mix [Member] | Identifiable assets [Member]
Segment Reporting Information [Line Items]
Total assets		324,500	[1],[3]	225,400	[1],[3]
Asphalt Mix [Member] | Segment sales [Member]
Segment Reporting Information [Line Items]
Total revenues		103,100	[3]	84,200	[3]
Concrete [Member]
Segment Reporting Information [Line Items]
Gross profit		800	[3],[4]	(9,200)	[3],[4]
Depreciation, depletion, accretion and amortization		2,700	[3],[4]	6,000	[3],[4]
Concrete [Member] | Identifiable assets [Member]
Segment Reporting Information [Line Items]
Total assets		173,300	[1],[3],[4]	240,400	[1],[3],[4]
Concrete [Member] | Segment sales [Member]
Segment Reporting Information [Line Items]
Total revenues		59,800	[3],[4]	96,000	[3],[4]
Calcium [Member]
Segment Reporting Information [Line Items]
Gross profit		600	[5]	100	[5]
Depreciation, depletion, accretion and amortization		200	[5]	1,100	[5]
Calcium [Member] | Identifiable assets [Member]
Segment Reporting Information [Line Items]
Total assets		5,700	[1],[5]	14,600	[1],[5]
Calcium [Member] | Segment sales [Member]
Segment Reporting Information [Line Items]
Total revenues		1,800	[5]	18,200	[5]
Calcium [Member] | Intersegment sales [Member]
Segment Reporting Information [Line Items]
Total revenues		0		(9,200)
Other [Member]
Segment Reporting Information [Line Items]
Depreciation, depletion, accretion and amortization		4,400		5,300
Corporate [Member]
Segment Reporting Information [Line Items]
Total assets		$ 122,700		$ 118,800

[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).