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Goodwill and Intangible Assets - Changes in the Carrying Amount of Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Jul. 30, 2016	Jul. 25, 2015	Jul. 26, 2014
Goodwill [Roll Forward]
Goodwill, gross, beginning balance	$ 467,420	$ 464,855
Goodwill, purchase price allocation adjustments	101	377
Goodwill acquisitions	38,403	2,188
Goodwill, gross, ending balance	505,924	467,420	$ 464,855
Accumulated impairment losses	(195,767)	(195,767)	(195,767)
Goodwill	$ 310,157	$ 271,653	$ 269,088
Fair Value Assumptions, Expected Term	7 years
Goodwill and Other Indefinite-Lived Intangible Assets | Maximum
Goodwill [Roll Forward]
Fair Value Inputs, Long-term Revenue Growth Rate	3.00%	2.50%	3.00%
Goodwill and Other Indefinite-Lived Intangible Assets | Minimum
Goodwill [Roll Forward]
Fair Value Inputs, Long-term Revenue Growth Rate	2.00%	1.50%	1.50%
Fair Value Inputs, Discount Rate	11.50%	11.50%	11.50%

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