Income Taxes - Components of Income Tax Provision (Benefit) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Current income tax provision (benefit):
Federal	$ 10	$ 15	$ 15
State	56	177	70
Foreign	5,537	1,417	681
Total current income tax provision (benefit)	5,603	1,609	766
Deferred income tax (benefit):
Federal	(1,773)	(2,276)	(5,245)
State	(104)	(35)	(183)
Foreign	(296)	(1,278)	(323)
Total deferred income tax (benefit)	(2,173)	(3,589)	(5,751)
Income tax provision (benefit)	$ 3,430	$ (1,980)	$ (4,985)