Debt Interest Rates at Period End (Details)	6 Months Ended
	Jan. 23, 2016	Jan. 24, 2015	Jul. 25, 2015
Standby Letters of Credit
Line of Credit Facility [Line Items]
Debt Instrument, Interest Rate at Period End	2.00%		1.75%
Credit Agreement - Term Loan (matures April 2020)
Line of Credit Facility [Line Items]
Debt Instrument, Interest Rate at Period End	2.42%		1.94%
Credit Agreement - Revolving facility (matures April 2020)
Line of Credit Facility [Line Items]
Debt Instrument, Interest Rate at Period End	2.66%		2.02%
Unutilized commitment fee (in percent)	0.40%	0.35%