Segment Data - Additional Information (Detail)	12 Months Ended
	Sep. 30, 2012 Customer	Sep. 30, 2011 Customer	Sep. 30, 2010 Customer
Segment Reporting Information [Line Items]
Number of customer accounted for 10% or more of revenues	0	0	0
Threshold of revenue by major customer	10% or more	10% or more	10% or more