Net Sales By Product Line (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Business Combination, Separately Recognized Transactions
Net Sales	$ 539,140	$ 445,003	$ 1,380,897	$ 1,145,204
Aggregates
Business Combination, Separately Recognized Transactions
Net Sales	371,102	362,618	985,361	916,875
Asphalt
Business Combination, Separately Recognized Transactions
Net Sales	29,198	12,297	61,921	37,554
Ready Mixed Concrete
Business Combination, Separately Recognized Transactions
Net Sales	33,143	9,729	82,634	22,266
Road Paving
Business Combination, Separately Recognized Transactions
Net Sales	56,250	10,017	99,355	19,425
Total Aggregates Business
Business Combination, Separately Recognized Transactions
Net Sales	489,693	394,661	1,229,271	996,120
Magnesia Based Chemicals
Business Combination, Separately Recognized Transactions
Net Sales	32,487	32,794	96,694	94,799
Dolomitic Lime
Business Combination, Separately Recognized Transactions
Net Sales	16,460	17,131	53,591	53,314
Others
Business Combination, Separately Recognized Transactions
Net Sales	500	417	1,341	971
Specialty Products
Business Combination, Separately Recognized Transactions
Net Sales	$ 49,447	$ 50,342	$ 151,626	$ 149,084