Goodwill (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011	Mar. 31, 2011
Changes in the carrying amount of goodwill by reportable segment
Goodwill, gross carrying amount, beginning balance	$ 3,339,380	$ 3,339,380
Goodwill, gross carrying amount, ending balance	3,339,380	3,339,380
Goodwill, accumulated impairment losses, beginning balance	(252,664)	(252,664)
Goodwill, accumulated impairment losses, ending balance	(252,664)	(252,664)
Goodwill, net of accumulated impairment losses, beginning balance	3,086,716	3,086,716	3,097,016
Goodwill, net of accumulated impairment losses, ending balance	3,086,716	3,086,716	3,097,016
Aggregates [Member]
Changes in the carrying amount of goodwill by reportable segment
Goodwill, gross carrying amount, beginning balance	2,995,083	2,995,083
Goodwill, gross carrying amount, ending balance	2,995,083	2,995,083
Goodwill, accumulated impairment losses, beginning balance	0	0
Goodwill, accumulated impairment losses, ending balance	0	0
Goodwill, net of accumulated impairment losses, beginning balance	2,995,083	2,995,083
Goodwill, net of accumulated impairment losses, ending balance	2,995,083	2,995,083
Concrete [Member]
Changes in the carrying amount of goodwill by reportable segment
Goodwill, gross carrying amount, beginning balance	0	0
Goodwill, gross carrying amount, ending balance	0	0
Goodwill, accumulated impairment losses, beginning balance	0	0
Goodwill, accumulated impairment losses, ending balance	0	0
Goodwill, net of accumulated impairment losses, beginning balance	0	0
Goodwill, net of accumulated impairment losses, ending balance	0	0
Asphalt Mix [Member]
Changes in the carrying amount of goodwill by reportable segment
Goodwill, gross carrying amount, beginning balance	91,633	91,633
Goodwill, gross carrying amount, ending balance	91,633	91,633
Goodwill, accumulated impairment losses, beginning balance	0	0
Goodwill, accumulated impairment losses, ending balance	0	0
Goodwill, net of accumulated impairment losses, beginning balance	91,633	91,633
Goodwill, net of accumulated impairment losses, ending balance	91,633	91,633
Cement [Member]
Changes in the carrying amount of goodwill by reportable segment
Goodwill, gross carrying amount, beginning balance	252,664	252,664
Goodwill, gross carrying amount, ending balance	252,664	252,664
Goodwill, accumulated impairment losses, beginning balance	(252,664)	(252,664)
Goodwill, accumulated impairment losses, ending balance	(252,664)	(252,664)
Goodwill, net of accumulated impairment losses, beginning balance	0	0
Goodwill, net of accumulated impairment losses, ending balance	$ 0	$ 0