Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands		12 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Statement of Comprehensive Income [Abstract]
Net income		$ 16,708	$ 6,588	$ 1,751
Other comprehensive loss, net of tax:
Foreign currency translation adjustment		(2,107)	(4,323)	(2,713)
Change in net unrealized gain (loss) on investments		53	(21)	43
Less income tax (provision) benefit		(20)	7	(17)
Reclassification of realized (gain) loss on investments included in net income (1)	[1]	(7)	1	0
Less income tax benefit (2)	[2]	3	0	0
Other comprehensive loss, net of tax		(2,078)	(4,336)	(2,687)
Comprehensive income (loss)		$ 14,630	$ 2,252	$ (936)

[1] Recorded in Other (expense) income, net in our Consolidated Statements of Operations.

[2] Recorded in Income tax provision in our Consolidated Statements of Operations.