CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	4 Months Ended	12 Months Ended
	Jan. 31, 2015	Jan. 30, 2016	Sep. 30, 2014	Sep. 30, 2013
Statement Of Income And Comprehensive Income [Abstract]
Net income (loss)	$ (17,380)	$ (4,483)	$ 10,497	$ 23,943
Foreign currency translation adjustments	(1)	(9)	4	(33)
Comprehensive income (loss)	$ (17,381)	$ (4,492)	$ 10,501	$ 23,910