Stockholders' Equity - Warrants (Details) $ in Millions		12 Months Ended
	Aug. 03, 2018 USD ($)	Feb. 02, 2019 USD ($) item shares	Feb. 03, 2018 USD ($) shares	Jan. 28, 2017 USD ($) tranche item shares
Warrants
Warrants issued to purchase shares of common stock | shares		4,085,803	957,806
Initial term	7 years
Fair value of stock warrants	$ 1.2
Hi Tech | Warrants
Warrants
Warrants issued to purchase shares of common stock | shares				120,000
Number of tranches of warrants | tranche				5
Number of shares vest in each tranches | shares				20,000
Initial term				5 years
Renewal period				5 years
Value of warrants until the related contingency is resolved				$ 0.0
Tranches | item		5		5
Fair value of stock warrants				$ 0.6
Contra revenue and additional paid-in capital recognized		$ 0.1	$ 0.1
Total unrecognized expenses related to first five tranches of stock warrant		$ 0.4
Expenses recognized over remaining life		3 years