CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jan. 27, 2018	Jan. 28, 2017	Jan. 27, 2018	Jan. 28, 2017
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Net income	$ 9,511	$ 5,992	$ 12,528	$ 10,101
Other comprehensive income:
Amortization of pension actuarial loss, net of tax	102	224	186	491
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, before Reclassification Adjustments, Net of Tax	0	(372)	0	(372)
Comprehensive income	$ 9,613	$ 6,588	$ 12,714	$ 10,964