Stockholders Equity - Amounts Reclassified Out of Accumulated Other Comprehensive Income (Loss) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Oct. 25, 2013	Oct. 26, 2012	Oct. 25, 2013	Oct. 26, 2012
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other income (expense), net	$ 3.3	$ 1.2	$ 5.2	$ 4.3
Net revenues	1,549.9	1,541.2	3,066.1	2,985.8
Net income	166.8	109.6	248.4	173.4
Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net income	1.4	2.1	0.3	(2.5)
Reclassification out of Accumulated Other Comprehensive Income | Unrealized Gains on Available-for-Sale Securities
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other income (expense), net	(1.0)	(0.5)	(1.1)	(0.6)
Reclassification out of Accumulated Other Comprehensive Income | Unrealized Gains (Losses) on Derivative Instruments
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net revenues	$ 2.4	$ 2.6	$ 1.4	$ (1.9)