Costs and Estimated Earnings in Excess of Billings (Details) - USD ($) $ in Thousands	Apr. 23, 2016	Jul. 25, 2015
Contractors [Abstract]
Costs incurred on contracts in progress	$ 308,196	$ 240,077
Estimated to date earnings	89,180	72,446
Total costs and estimated earnings	397,376	312,523
Less: billings to date	(50,277)	(54,689)
Total costs in excess of billings	347,099	257,834
Costs and estimated earnings in excess of billings	358,236	274,730
Billings in excess of costs and estimated earnings	(11,137)	(16,896)
Total costs in excess of billings	$ 347,099	$ 257,834