Stock-Based Compensation, SARs (Details) (Stock Appreciation Rights (SARs), USD $)	9 Months Ended
	Jan. 24, 2015
Stock-Based Compensation
Percentage vesting each year from date of grant	25.00%
Period from grant date for first vesting	1 year
Vesting period	4 years
Awards Granted During 2014
Fair value assumptions
Risk-free interest rate (as a percent)	1.06%
Dividend rate (as a percent)	1.17%
Expected life in years	3 years 4 months 24 days
Stock price volatility (as a percent)	38.80%
Fair value per share (in dollars per share)	10.92
Awards Granted During 2013
Fair value assumptions
Risk-free interest rate (as a percent)	0.64%
Dividend rate (as a percent)	1.17%
Expected life in years	2 years 5 months 23 days
Stock price volatility (as a percent)	32.35%
Fair value per share (in dollars per share)	15.00