CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Statement Of Income And Comprehensive Income [Abstract]
Net income (loss)	$ (8,564)	$ 3,752	$ (19,191)	$ 38,744
Other comprehensive income (loss):
Change in unrealized gains (losses) on available-for-sale securities (net of tax)	(8)	(3)	13	(3)
Foreign currency translations adjustments	1,192	550	(3,426)	(489)
Total other comprehensive income (loss)	1,184	547	(3,413)	(492)
Total comprehensive income (loss)	$ (7,380)	$ 4,299	$ (22,604)	$ 38,252