Segment Information - Narrative (Details) $ in Thousands	6 Months Ended	12 Months Ended
	Jul. 31, 2016	Jan. 29, 2017 USD ($)	Jan. 31, 2016 USD ($)
Segment Reporting Information [Line Items]
Number of operating segments	5	4	5
Number of operating segments that aggregate into one reportable segment		4
Number of reportable segments		1
Net book value of equipment and machinery		$ 108,910	$ 101,006
Machinery and equipment | Foundry in China
Segment Reporting Information [Line Items]
Net book value of equipment and machinery		5,100	5,500
Machinery and equipment | Foundry In Malaysia [Member]
Segment Reporting Information [Line Items]
Net book value of equipment and machinery		$ 2,300	$ 1,600