Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Jul. 29, 2017	Jul. 30, 2016	Jul. 25, 2015
Statement of Comprehensive Income [Abstract]
Change in net unrealized gains, tax benefit (expense)	$ 74	$ (49)	$ 14
Net (gains) losses reclassified into earnings, tax expense (benefit)	(37)	0	57
Change in unrealized gains and losses, tax benefit (expense)	(5)	7	19
Net (gains) losses reclassified into earnings, tax expense (benefit)	(5)	(4)	(18)
Net change in cumulative translation adjustment and actuarial gains and losses, tax benefit (expense)	$ (13)	$ (42)	$ 63