Available-for-Sale Debt Investments and Equity Investments - Maturities of Fixed Income Securities (Details) - USD ($) $ in Millions	Jul. 27, 2019	Jul. 28, 2018
Amortized Cost
Within 1 year	$ 6,322
After 1 year through 5 years	12,191
After 5 years through 10 years	1,643
After 10 years	9
Mortgage-backed securities with no single maturity	1,425
Amortized Cost	21,590	$ 37,512
Fair Value
Within 1 year	6,324
After 1 year through 5 years	12,218
After 5 years through 10 years	1,687
After 10 years	10
Mortgage-backed securities with no single maturity	1,421
Total	$ 21,660	$ 37,009

Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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