Other Charges, Net - Additional Information (Details) - USD ($)		3 Months Ended		9 Months Ended
	Jul. 31, 2017	Oct. 28, 2017	Oct. 29, 2016	Oct. 28, 2017	Oct. 29, 2016
Other Charges Net Related To Management And Organizational Changes And Proposed Business Combination [Line Items]
Net charges related to management and organizational changes		$ 2,636,000	$ 36,000	$ 2,633,000	$ 707,000
Net reimbursement amount for certain costs incurred in connection with merger agreement				(1,000,000)
Net charges related to Merger		464,000	$ 423,000	$ 1,113,000	$ 1,296,000
Orchestra-Premaman S.A., and Certain Other Affiliates of Orchestra
Other Charges Net Related To Management And Organizational Changes And Proposed Business Combination [Line Items]
Charges related to proxy solicitation for proposed business combination		$ 426,000
Termination agreement entry date				Jul. 27, 2017
Termination Agreement
Other Charges Net Related To Management And Organizational Changes And Proposed Business Combination [Line Items]
Net reimbursement amount for certain costs incurred in connection with merger agreement	$ 1,000,000
Terminated Ancillary Agreement
Other Charges Net Related To Management And Organizational Changes And Proposed Business Combination [Line Items]
Revenue under consulting service agreements				$ 44,000