Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 2,300	$ 2,653
Other comprehensive (loss) income:
Unrealized holding gains (losses) on available-for-sale securities, net of tax	46	(2)
Foreign currency translation adjustments	(2,254)	408
Other comprehensive (loss) income	(2,208)	406
Comprehensive income	$ 92	$ 3,059