Debt Convertible Note Hedge and Warrant Transactions (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		12 Months Ended
	Sep. 15, 2015	Jul. 30, 2016	Jul. 25, 2015	Jul. 26, 2014
Debt Instrument [Line Items]
Payments for Hedge, Financing Activities		$ 115,818	$ 0	$ 0
Proceeds from sale of warrants		$ 74,690	$ 0	$ 0
Convertible Note Hedge
Debt Instrument [Line Items]
Derivative, Number of Instruments Held	5,006
Debt Instrument, Convertible, Conversion Price	$ 96.89
Payments for Hedge, Financing Activities	$ 115,800
Deferred Tax Liabilities, Derivatives	43,400
Deferred Tax Assets, Derivative Instruments	$ 43,200
0.75% Convertible Senior Notes Due 2021
Debt Instrument [Line Items]
Debt Instrument, Convertible, Conversion Price	$ 96.89
Payments for Hedge, Financing Activities	$ 41,100
Class of Warrant or Right, Number of Securities Called by Warrants or Rights	5,006
Class of Warrant or Right, Exercise Price of Warrants or Rights	$ 130.43
Proceeds from sale of warrants	$ 74,700