Summary of Significant Accounting Policies - Share-based Compensation - Performance-based Restricted Stock Units (Details) - Performance-based restricted stock units - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 28, 2017	Oct. 29, 2016	Oct. 28, 2017	Oct. 29, 2016
Performance-based restricted stock units
Issued (in shares)			21	24
Compensation expense	$ 1,618	$ 1,468	$ 4,437	$ 2,903
Unrecognized compensation cost	$ 9,708		$ 9,708