Related Party Transactions (Details) - USD ($) $ in Thousands	9 Months Ended		12 Months Ended
	Apr. 25, 2015	Apr. 26, 2014	Jul. 25, 2015
Related Party Transaction [Line Items]
Future minimum payments due 2016			$ 17,016
Future minimum payments due 2017			11,807
Future minimum payments due 2018			6,867
Future minimum payments due 2019			3,724
Future minimum payments due 2020			2,540
Future minimum payments due thereafter			6,627
Real property and equipment leases
Related Party Transaction [Line Items]
Total expense under lease agreements	$ 2,722	$ 1,685	1,862
Subcontractors and materials expense
Related Party Transaction [Line Items]
Total expense under lease agreements	$ 2,532	$ 2,069	700
Affiliated Entity
Related Party Transaction [Line Items]
Future minimum payments due 2016			1,000
Future minimum payments due 2017			800
Future minimum payments due 2018			400
Future minimum payments due 2019			300
Future minimum payments due 2020			300
Future minimum payments due thereafter			$ 100