CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (Unaudited) - USD ($)	3 Months Ended		9 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (14,376,000)	$ (11,654,000)	$ (37,584,000)	$ (33,661,000)
Other comprehensive income (loss)
Change in unrealized (losses) gains on available-for-sale securities, net of tax	(10,000)	16,000	(61,000)	21,000
Foreign currency translation adjustments	452,000	115,000	1,499,000	(1,473,000)
Total other comprehensive income (loss)	442,000	131,000	1,438,000	(1,452,000)
Total comprehensive loss	$ (13,934,000)	$ (11,523,000)	$ (36,146,000)	$ (35,113,000)