Significant Customers - Additional Information (Detail)	12 Months Ended
	Sep. 30, 2013 customer	Sep. 30, 2012 customer	Sep. 30, 2011 customer
Revenue, Major Customer [Line Items]
Number of major customer by revenue	1	1	2
Percentage of revenues by customer	11.00%	13.00%
Customer 1
Revenue, Major Customer [Line Items]
Percentage of revenues by customer	11.00%		15.00%
Customer 2
Revenue, Major Customer [Line Items]
Percentage of revenues by customer			13.00%