Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 2,513	$ 3,614
Other comprehensive income (loss), net of tax:
Unrealized holding losses on available-for-sale securities arising during the period	(2)	(1,089)
Reclassification adjustment for realized gains included in net income		7
Foreign currency translation adjustments	408
Other comprehensive income (loss)	406	(1,082)
Comprehensive income	$ 2,919	$ 2,532