Reconciliation of Reportable Segment Gross Profit to Corresponding Consolidated Amounts (Detail) (USD $) In Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2009	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2009
Segment Reporting, Other Significant Reconciling Item [Line Items]
Gross profit (loss)		$ 223,021	$ 166,295	$ (5,996)
Impairment of long-lived assets	(35,100)			(35,512)
Operating Segments, Total
Segment Reporting, Other Significant Reconciling Item [Line Items]
Gross profit (loss)		223,021	166,295	14,928
Cost of Sales
Segment Reporting, Other Significant Reconciling Item [Line Items]
Impairment of long-lived assets				$ (20,924)