Share Repurchases (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Oct. 28, 2018	Oct. 29, 2017	Jul. 29, 2018
Statement [Line Items]
Common Stock, Shares Authorized	560		560
Common Stock, Par or Stated Value Per Share	$ 0.0375		$ 0.0375
Preferred Stock, Shares Authorized	40		40
Preferred Stock, Shares Issued	0		0
Shares repurchased, value	$ 0	$ 86
March 2017 Program [Member]
Statement [Line Items]
Authorized amount for shares repurchase	1,500
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 1,296
Treasury Stock [Member]
Statement [Line Items]
Treasury stock purchased, shares	0	2
Shares repurchased, value	$ 0	$ 86