Income Taxes - Components of Income Tax Provision (Benefit) (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012
Current income tax provision (benefit):
Federal	$ 15	$ 15	$ 15
State	177	70	213
Foreign	1,417	681	(1,374)
Total current income tax provision (benefit)	1,609	766	(1,146)
Deferred income tax (benefit):
Federal	(2,276)	(5,245)	(121,203)
State	(35)	(183)	(439)
Foreign	(1,278)	(323)	(3,413)
Total deferred income tax (benefit)	(3,589)	(5,751)	(125,055)
Income tax provision (benefit)	$ (1,980)	$ (4,985)	$ (126,201)