Restructuring (Details) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Oct. 24, 2015 USD ($)	Oct. 25, 2014 USD ($)	Oct. 24, 2015 USD ($)	Oct. 25, 2014 USD ($)	Apr. 25, 2015 facility
Restructuring
Number of facilities sold | facility					2
Restructuring charges
Pre-tax restructuring charges since inception of plan	$ 8,100		$ 8,100
Restructuring charges since inception of plan, net of tax	5,200		5,200
Pre-tax restructuring (income) expense	200	$ 100	352	$ (332)
Restructuring (income) expense, net of tax	100	$ 100	200	$ (200)
Restructuring liability	400		400
Continuing Operations
Restructuring charges
Pre-tax restructuring charges since inception of plan	4,900		4,900
Restructuring charges since inception of plan, net of tax	3,100		3,100
Discontinued Operations
Restructuring charges
Pre-tax restructuring charges since inception of plan	3,200		3,200
Restructuring charges since inception of plan, net of tax	$ 2,100		$ 2,100