Segment Geographic and Significant Customer Information - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Oct. 26, 2012	Oct. 28, 2011	Oct. 26, 2012	Oct. 28, 2011	Apr. 27, 2012
Segment Reporting Information [Line Items]
Net revenues	$ 1,541.2	$ 1,507.0	$ 2,985.8	$ 2,965.2
Threshold for disclosure percentage	10.00%	10.00%	10.00%	10.00%	10.00%
United States
Segment Reporting Information [Line Items]
Net revenues	$ 797.6	$ 770.4	$ 1,509.0	$ 1,459.7
International
Segment Reporting Information [Line Items]
Threshold for disclosure percentage	10.00%	10.00%	10.00%	10.00%