Property and Equipment Net on Geographical Basis (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012
Segment Reporting Information [Line Items]
Property and equipment, net	$ 36,677	$ 45,155
Concentration of risk, percentage	100.00%	100.00%	100.00%
United States
Segment Reporting Information [Line Items]
Property and equipment, net	29,276	39,737
United States | Property Plant and Equipment
Segment Reporting Information [Line Items]
Concentration of risk, percentage	80.00%	88.00%
International
Segment Reporting Information [Line Items]
Property and equipment, net	$ 7,401	$ 5,418
International | Property Plant and Equipment
Segment Reporting Information [Line Items]
Concentration of risk, percentage	20.00%	12.00%