Capitalization - Warrants (Details) $ in Thousands	3 Months Ended	6 Months Ended
	Jul. 29, 2017 USD ($) shares	Jul. 29, 2017 USD ($) tranche shares	Jan. 28, 2017 USD ($)
Warrants
Warrants		$ 26
Warrants | Hi-Tec License
Warrants
Warrants issued to purchase shares of common stock | shares	120,000	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
Fair value of stock warrants			$ 567
Warrants	$ 13	$ 26