Stock Incentive and Purchase Plans (Schedule of Stock Options Rollforward) (Details) (USD $)	12 Months Ended
	Apr. 26, 2013
Stock Incentive and Purchase Plans [Abstract]
Outstanding - beginning of period, shares	1,441,057
Granted, shares	238,459
Execised, shares	(501,050)
Forfeited, shares	(15,772)
Expired, shares	(1,267)
Outstanding - end of period, shares	1,161,427
Fully vested and exercisable - end of period, shares	577,403
Fully vested and expected to vest - end of period, shares	1,130,897
Weighted Average Exercise Price, beginning of period	$ 23.75
Weighted Average Exercise Price, Granted	$ 43.63
Weighted Average Exercise Price, Exercised	$ 23.94
Weighted Average Exercise Price, Forfeited	$ 28.52
Weighted Average Exercise Price, Expired	$ 36.87
Weighted Average Exercise Price, end of period	$ 27.67
Weighted Average Exercise Price, Fully vested and excercisable - end of period	$ 23.40
Weighted Average Exercise Price, Fully vested and expected to vest - end of period	$ 27.45
Weighted Average Remaining Contractual Term, Outstanding - end of period	6 years 4 months 13 days
Weighted Average Remaining Contractual Term - Fully vested and exercisable - end of period	4 years 6 months 4 days
Weighted Average Remaining Contractual Term - Fully vested and expected to vest - end of period	6 years 3 months 15 days
Aggregate Intrinsic Value, Outstanding - end of period	$ 18,164,690
Aggregate Intrinsic Value, Fully vested and exercisable - end of period	11,433,687
Aggregate Intrinsic Value, Fully vested and expected to vest - end of period	$ 17,922,143