Stock Incentive and Purchase Plans (Summary of Performance-Based and Market-Based Restricted Stock and Restricted Stock Unit Awards) (Details) (Performance-based restricted stock and restricted stock unit and market-based awards [Member], USD $)	12 Months Ended
	Apr. 26, 2013	Apr. 27, 2012	Apr. 29, 2011
Performance-based restricted stock and restricted stock unit and market-based awards [Member]
Aggregate fair value of perormance-based share grants that vested during the year	$ 3,318,681	$ 0	$ 0
Weighted average grant date fair value of performance-based share grants issued during the fiscal year	$ 50.10	$ 25.23	$ 0.00