Segment and Geographic Data - Information by Geographic Area (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Apr. 30, 2016	Jan. 30, 2016	Oct. 31, 2015	Aug. 01, 2015	Apr. 25, 2015	Jan. 24, 2015	Oct. 25, 2014	Jul. 26, 2014	Apr. 30, 2016	Apr. 25, 2015	Apr. 26, 2014
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	$ 1,453,770	$ 1,400,853	$ 1,389,210	$ 1,142,870	$ 1,035,061	$ 958,628	$ 978,220	$ 938,956	$ 5,386,703	$ 3,910,865	$ 3,585,141
Property and equipment, net	293,315				204,133				293,315	204,133
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales									4,457,254	3,029,541	2,933,091
Property and equipment, net	278,667				190,618				278,667	190,618
United Kingdom [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales									626,603	649,541	419,341
Property and equipment, net	2,459				2,857				2,459	2,857
Canada [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales									302,846	231,783	$ 232,709
Property and equipment, net	$ 12,189				$ 10,658				$ 12,189	$ 10,658