Segment Geographic and Significant Customer Information - Schedule of Revenues by Geographic Region (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Apr. 26, 2013	Jan. 25, 2013	Oct. 26, 2012	Jul. 27, 2012	Apr. 27, 2012	Jan. 27, 2012	Oct. 28, 2011	Jul. 29, 2011	Apr. 26, 2013	Apr. 27, 2012	Apr. 29, 2011
Segment Reporting Information [Line Items]
Net revenues	$ 1,716.5	$ 1,630.1	$ 1,541.2	$ 1,444.6	$ 1,702.5	$ 1,565.5	$ 1,507.0	$ 1,458.2	$ 6,332.4	$ 6,233.2	$ 5,122.6
Americas (United States, Canada And Latin America)
Segment Reporting Information [Line Items]
Net revenues									3,552.5	3,529.7	2,899.0
Europe, Middle East And Africa
Segment Reporting Information [Line Items]
Net revenues									1,928.8	1,936.5	1,719.1
Asia Pacific
Segment Reporting Information [Line Items]
Net revenues									$ 851.1	$ 767.0	$ 504.5