Property, Plant and Equipment - Additional Information (Detail) (USD $) In Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2009	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2009
Property, Plant and Equipment [Line Items]
Depreciation expense		$ 12,600	$ 14,600	$ 15,600
Impairment of long-lived assets	35,100			35,512
Buildings and Leasehold Improvements
Property, Plant and Equipment [Line Items]
Impairment of long-lived assets				$ 1,300