Acquisitions and Divestitures - Additional information (Detail) (USD $)	3 Months Ended						12 Months Ended
	Dec. 31, 2012 acre T	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011 Facility	Dec. 31, 2011
Significant Acquisitions and Disposals [Line Items]
Number of tracts	2
Area of land sold	148
Proceeds from sale of land	$ 57,690,000
Gain (loss) on sale of property	41,155,000		12,342,000	5,979,000
Cash proceeds from divestiture	10,476,000					61,774,000
Gain recognized on divested assets	5,646,000				587,000	39,659,000
Payment for the sale of future production	75,200,000
Transaction cost	1,617,000
Volumetric production payment termination date	Dec. 31, 2052
Volumetric production payment percentage sold	10.50%
Volumetric production payment estimated tons to be delivered	15,000,000
Estimated deferred revenue to be recognized next year	1,200,000
Proceeds from sale of mitigation credits			13,469,000
Proceeds from sale of real estate				9,691,000
Loss on assets classified as held for sale	1,738,000
Total consideration for acquired assets included in fair value of acquired assets					35,406,000		35,406,000
Cash paid for acquiring facilities					10,000,000		10,000,000
Transaction related costs					531,000
Number of aggregate facilities sold						4
Receivables						2,400,000
Goodwill included in book value of assets						(10,300,000)	(10,300,000)
Number of shares of common stock valued at the closing date							432,407
Closing date price							$ 42.85
Total consideration net of cash acquired					18,529,000		18,529,000
Number of shares issued to seller		60,855					372,992
Amortizable intangible assets recognized					6,419,000		6,419,000
Estimated weighted-average period intangible assets are to be amortized							20 years
Maximum
Significant Acquisitions and Disposals [Line Items]
Tons subject to volumetric production payment	143,200,000
Concrete
Significant Acquisitions and Disposals [Line Items]
Number of facilities acquired							10
Goodwill included in book value of assets							0
Facilities
Significant Acquisitions and Disposals [Line Items]
Area of land sold	197
Aggregates
Significant Acquisitions and Disposals [Line Items]
Number of facilities acquired							3
Number of facilities divested							2
Goodwill included in book value of assets							(10,300,000)
Rail Distribution Yard
Significant Acquisitions and Disposals [Line Items]
Number of facilities acquired							1
Asphalt Mix
Significant Acquisitions and Disposals [Line Items]
Number of facilities divested							1
Goodwill included in book value of assets							$ 0
Ready Mixed Concrete
Significant Acquisitions and Disposals [Line Items]
Number of facilities divested							2
Recycling Operation
Significant Acquisitions and Disposals [Line Items]
Number of facilities divested							1