Stock Incentive and Purchase Plans (Summary of Restricted Stock Service-Based Activity) (Details) (Service-based restricted stock and restricted stock unit awards [Member], USD $)	12 Months Ended
	Apr. 26, 2013	Apr. 27, 2012	Apr. 29, 2011
Service-based restricted stock and restricted stock unit awards [Member]
Weighted average grant date fair value of service-based share grants issued during the fiscal year	$ 44.31	$ 26.58	$ 27.23
Aggregate fair value of service-based share grants that vested during the year	$ 15,969,922	$ 7,638,546	$ 2,978,345