Condensed Consolidated Statements of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	[1]
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 4,682	$ (4,487)
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustment	(1,569)	271
Change in net unrealized gain (loss) on investments	5	(21)
Less income tax (provision) benefit	(2)	3
Other comprehensive (loss) income, net of tax	(1,566)	253
Comprehensive income (loss)	$ 3,116	$ (4,234)

[1] Prior period information has been restated for the adoption of ASU No. 2014-09, “Revenue from Contracts with Customers (Topic 606),” which we adopted on October 1, 2018.