Stock-Based Compensation - Stock Options (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Jul. 28, 2018	Apr. 27, 2019	Apr. 28, 2018	Apr. 29, 2017
Stock-Based Compensation
Expense recognized		$ 11,320	$ 9,879	$ 10,551
Minimum
Stock-Based Compensation
Vesting period		1 year
Maximum
Stock-Based Compensation
Vesting period		4 years
Stock Options
Stock-Based Compensation
Vesting period		10 months
Cash received for exercises of stock options		$ 16,200	$ 4,400	3,600
Number of Shares
Outstanding at beginning of period (in shares)	1,837,000	1,837,000
Granted (in shares)	423,273	423,000
Canceled (in shares)		(58,000)
Exercised (in shares)		(761,000)
Outstanding at end of period (in shares)		1,441,000	1,837,000
Exercisable (in shares)		516,000
Weighted Average Exercise Price
Outstanding at beginning of period (in dollars per share)	$ 24.18	$ 24.18
Granted (in dollars per share)		33.15
Canceled (in dollars per share)		30.44
Exercised (in dollars per share)		21.28
Outstanding at end of period (in dollars per share)		28.09	$ 24.18
Exercisable (in dollars per share)		$ 25.78
Additional information
Weighted Average Remaining Contractual Term, Outstanding		7 years 8 months 12 days	7 years 4 months 24 days
Weighted Average Remaining Contractual Term, Exercisable		6 years 9 months 18 days
Aggregate Intrinsic Value, Outstanding		$ 6,557	$ 9,407
Aggregate Intrinsic Value, Exercised		9,933	$ 2,200	$ 4,900
Aggregate Intrinsic Value, Exercisable		3,450
Unrecognized compensation cost		$ 2,000
Period for recognition of unrecognized compensation costs		1 year 8 months 12 days
Vested during the period (in shares)		500,000
Fair value assumptions
Risk-free interest rate (as a percent)		2.82%	1.84%	1.30%
Dividend rate (as a percent)		1.45%	1.61%	1.54%
Expected life in years		5 years	5 years	5 years
Stock price volatility (as a percent)		33.07%	32.12%	38.87%
Fair value per share (in dollars per share)		$ 9.65	$ 7.16	$ 7.99
Stock Options | Minimum
Stock-Based Compensation
Purchase price of common stock at date of grant (as a percent)		100.00%
Stock Options | Selling, general and administrative expense
Stock-Based Compensation
Expense recognized		$ 3,500	$ 4,200	$ 3,400
Stock Options | Former Long-Term Equity Award Plan
Stock-Based Compensation
Award expiration term		10 years