Segment Information - Revenue by Country (Details) - Net sales revenue	12 Months Ended
	Jan. 27, 2019	Jan. 28, 2018	Jan. 29, 2017
Geographic Information And Concentration Of Risk [Line Items]
Concentration risk, percentage	100.00%	100.00%	100.00%
Geographic Concentration Risk [Member]
Geographic Information And Concentration Of Risk [Line Items]
Concentration risk, percentage	66.00%	60.00%	57.00%
China Including Hong Kong [Member] | Geographic Concentration Risk [Member]
Geographic Information And Concentration Of Risk [Line Items]
Concentration risk, percentage	55.00%	51.00%	48.00%
United States | Geographic Concentration Risk [Member]
Geographic Information And Concentration Of Risk [Line Items]
Concentration risk, percentage	11.00%	9.00%	9.00%