Restructuring and Severance Charges - Schedule of Restructuring Activity (Details) - USD ($) $ in Thousands	6 Months Ended
	Oct. 27, 2017	Oct. 28, 2016
Selling, General and Administrative Expenses
Restructuring Reserve [Roll Forward]
Restructuring and related severance charges incurred		$ 807
Corporate and Other
Restructuring Reserve [Roll Forward]
Balance, beginning	$ 2,800	2,698
Restructuring and related severance charges incurred	0	807
Amounts paid	(1,974)	(2,333)
Adjustments	(328)	(42)
Balance, ending	$ 498	$ 1,130