Net Sales By Product Line (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Business Combination, Separately Recognized Transactions
Net sales	$ 345,150	$ 350,532
Gross profit (loss)	12,587	23,826
Aggregates
Business Combination, Separately Recognized Transactions
Net sales	247,791	257,346
Gross profit (loss)	2,061	11,414
Asphalt
Business Combination, Separately Recognized Transactions
Net sales	9,633	12,539
Gross profit (loss)	(2,455)	(735)
Ready Mixed Concrete
Business Combination, Separately Recognized Transactions
Net sales	27,368	20,255
Gross profit (loss)	(315)	(1,229)
Road Paving
Business Combination, Separately Recognized Transactions
Net sales	5,189	8,676
Gross profit (loss)	(4,287)	(2,855)
Total Aggregates Business
Business Combination, Separately Recognized Transactions
Net sales	289,981	298,816
Gross profit (loss)	(4,996)	6,595
Magnesia Based Chemicals
Business Combination, Separately Recognized Transactions
Net sales	35,859	36,398
Gross profit (loss)	11,531	12,918
Dolomitic Lime
Business Combination, Separately Recognized Transactions
Net sales	19,126	14,973
Gross profit (loss)	8,237	6,550
Others
Business Combination, Separately Recognized Transactions
Net sales	184	345
Gross profit (loss)	(186)	(78)
Specialty Products
Business Combination, Separately Recognized Transactions
Net sales	55,169	51,716
Gross profit (loss)	19,582	19,390
Corporate
Business Combination, Separately Recognized Transactions
Gross profit (loss)	$ (1,999)	$ (2,159)