Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Apr. 25, 2020	Apr. 27, 2019	Apr. 25, 2020	Apr. 27, 2019
Statement of Comprehensive Income [Abstract]
Change in net unrealized gains, tax benefit (expense)	$ 3	$ (64)	$ (26)	$ (63)
Net (gains) losses reclassified into earnings, tax expense (benefit)	2	5	14	4
Change in unrealized gains and losses, tax benefit (expense)	(2)		(1)
Change in unrealized gains and losses, tax benefit (expense)		(2)		0
Net (gains) losses reclassified into earnings, tax expense (benefit)	0		0
Net (gains) losses reclassified into earnings, tax expense (benefit)		0		0
Net change in cumulative translation adjustment and actuarial gains and losses, tax benefit (expense)	$ 3	$ (1)	$ 2	$ (2)

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Amount of tax expense (benefit) before reclassification adjustments of unrealized holding gain (loss) on available-for-sale securities and unrealized holding gain (loss) related to transfers of securities into the available-for-sale category and out of the held-to-maturity category.

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Amount, before reclassification, of tax expense (benefit) for gain (loss) from derivative instrument designated and qualifying as cash flow hedge included in assessment of hedge effectiveness.

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Amount of tax expense (benefit) for reclassification of gain (loss) from accumulated other comprehensive income (AOCI) for derivative instrument designated and qualifying as cash flow hedge included in assessment of hedge effectiveness.

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Amount of tax expense (benefit) of reclassification adjustment from accumulated other comprehensive income for unrealized gain (loss) realized upon the sale of available-for-sale securities.

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Amount of tax expense (benefit) of reclassification adjustment from accumulated other comprehensive income of accumulated gain (loss) realized from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's deferred hedging gain (loss).

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Amount of tax expense (benefit), before reclassification adjustments, related to increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

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