Commitments and Contingencies - Additional Information (Detail) (USD $) In Millions, unless otherwise specified				6 Months Ended
	Oct. 25, 2013	Apr. 26, 2013	Oct. 25, 2013 Contract Manufacturers	Oct. 25, 2013 Software Maximum	Oct. 25, 2013 Software Minimum	Oct. 25, 2013 Hardware Maximum	Oct. 25, 2013 Hardware Minimum	Oct. 25, 2013 Capital Purchase Commitments	Oct. 25, 2013 Other Purchase Commitments
Commitments and Contingencies Disclosure [Line Items]
Future annual minimum lease payments	$ 215.7
Accrued purchase commitments with contract manufacturers	10.9	9.5
Significant commitment			$ 306.8					$ 33.6	$ 202.4
Product warranty term				5 years	90 days	5 years	1 year