Statements of Cash Flows - Supplemental Cash Flows and Non Cash Investing and Financing Activities (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Apr. 25, 2014	Apr. 26, 2013	Apr. 27, 2012
Non-cash Investing and Financing Activities:
Reclassification of equity component of Convertible Notes	$ 0	$ 62.6	$ 52.0
Capital expenditures incurred but not paid	18.0	20.2	31.4
Acquisition of software through long-term financing	11.4	0.8	3.6
Vested options assumed in acquisition	0	1.2	0
Supplemental Cash Flow Information:
Income taxes paid, net of refunds	58.1	46.7	48.2
Interest paid, net of capitalized interest	$ 35.2	$ 22.8	$ 21.4