Segment Information (Detail) - Major customers (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Customer A
Segment Reporting Information [Line Items]
Amount (in Dollars)	$ 1.3	$ 3.5	$ 12.3	$ 10.2
% of Revenues	7.00%	16.00%	19.00%	16.00%
Customer B
Segment Reporting Information [Line Items]
Amount (in Dollars)	2.6	2.0	9.9	12.2
% of Revenues	14.00%	9.00%	15.00%	20.00%
Customer C
Segment Reporting Information [Line Items]
Amount (in Dollars)	3.8	0.7	8.0	1.5
% of Revenues	20.00%	3.00%	12.00%	2.00%
Customer D
Segment Reporting Information [Line Items]
Amount (in Dollars)	$ 0	$ 2.6	$ 0	$ 3.3
% of Revenues	0.00%	12.00%	0.00%	5.00%