Derivative Financial Instruments - Effect of Interest Rate Contracts on Consolidated Statements of Income (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Apr. 26, 2014	Apr. 27, 2013	Apr. 28, 2012
Interest rate contracts [Member] | Other income (expense), net [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Other income (expense), net and Other comprehensive Income	$ 4	$ 78	$ 2
Interest rate swap [Member] | Other comprehensive Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Other income (expense), net and Other comprehensive Income	$ 5,660