Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands		12 Months Ended
		Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Net income		$ 1,303	$ 9,366	$ 16,708
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustment		(865)	2,041	(2,107)
Change in net unrealized (loss) gain on investments		(31)	(14)	53
Less income tax benefit (provision)		6	5	(20)
Reclassification of realized loss (gain) on investments included in net income (1)	[1]	31	0	(7)
Less income tax benefit (provision) (2)	[2]	(8)	0	3
Other comprehensive (loss) income, net of tax		(867)	2,032	(2,078)
Comprehensive income		$ 436	$ 11,398	$ 14,630

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

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