Interest Expense, Net - Interest Expense, Net (Details) - USD ($) $ in Thousands	4 Months Ended	12 Months Ended
	Jan. 31, 2015	Jan. 28, 2017	Jan. 30, 2016	Sep. 30, 2014
Interest expense, net
Interest expense	$ 245	$ 3,578	$ 1,529	$ 418
Interest income	(3)	(3)	(9)	(14)
Interest expense, net	$ 242	$ 3,575	$ 1,520	$ 404