Commitments and Contingencies - Additional Information (Detail) (USD $) In Millions, unless otherwise specified			6 Months Ended
	Oct. 24, 2014	Apr. 25, 2014	Oct. 24, 2014 Software	Oct. 24, 2014 Hardware	Oct. 24, 2014 Maximum	Oct. 24, 2014 Capital Purchase Commitments	Oct. 24, 2014 Other Purchase Commitments	Oct. 24, 2014 Contract Manufacturers
Commitments and Contingencies Disclosure [Line Items]
Future annual minimum lease payments	$ 206.5
Accrued purchase commitments with contract manufacturers	8.7	11.5
Purchase commitments						$ 73.3	$ 197.0	$ 253.2
Product warranty term			90 days	3 years
Terms of recourse leases					3 years