Long-Lived Assets (Details 2) (USD $)	3 Months Ended			12 Months Ended
	Jun. 30, 2012	Sep. 30, 2011	Mar. 31, 2011	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010
Depreciation on Property, Plant and Equipment
Depreciation expense				$ 30,800,000	$ 41,900,000	$ 38,200,000
Asset impairment	13,000,000	35,000,000	37,000,000			37,962,000
Heavy Construction Materials
Depreciation on Property, Plant and Equipment
Asset impairment						$ 3,500,000