Long-Lived Assets (Details 4) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Schedule of changes in the carrying amount of goodwill
Goodwill, Beginning Balance	$ 137,198	$ 116,671
Goodwill related to acquisitions	38,388	20,527
Goodwill, Ending Balance	175,586	137,198
Light Building Products
Schedule of changes in the carrying amount of goodwill
Goodwill, Beginning Balance	21,199	672
Goodwill related to acquisitions	35,488	20,527
Goodwill, Ending Balance	56,687	21,199
Heavy Construction Materials
Schedule of changes in the carrying amount of goodwill
Goodwill, Beginning Balance	115,999	115,999
Goodwill related to acquisitions	2,900	0
Goodwill, Ending Balance	$ 118,899	$ 115,999