v3.10.0.1

Fair Value (Assets and Liabilities Measured at Fair Value on Recurring Basis) (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Millions | Oct. 27, 2018 | Jul. 28, 2018
--- | --- | ---
Fair Value Measurements [Line Items] |  |
Assets: | $ 40,767 | $ 44,506
Liabilities: | 91 | 74
Fair Value, Inputs, Level 1 [Member] |  |
Fair Value Measurements [Line Items] |  |
Assets: | 6,332 | 7,495
Liabilities: | 0 | 0
Level 2 |  |
Fair Value Measurements [Line Items] |  |
Assets: | 34,435 | 37,011
Liabilities: | 91 | 74
Derivative assets |  |
Fair Value Measurements [Line Items] |  |
Assets: | 6 | 2
Derivative assets | Fair Value, Inputs, Level 1 [Member] |  |
Fair Value Measurements [Line Items] |  |
Assets: | 0 | 0
Derivative assets | Level 2 |  |
Fair Value Measurements [Line Items] |  |
Assets: | 6 | 2
Derivative liabilities |  |
Fair Value Measurements [Line Items] |  |
Liabilities: | 91 | 74
Derivative liabilities | Fair Value, Inputs, Level 1 [Member] |  |
Fair Value Measurements [Line Items] |  |
Liabilities: | 0 | 0
Derivative liabilities | Level 2 |  |
Fair Value Measurements [Line Items] |  |
Liabilities: | 91 | 74
Money market funds | Cash equivalents: |  |
Fair Value Measurements [Line Items] |  |
Assets: | 6,332 | 6,890
Money market funds | Cash equivalents: | Fair Value, Inputs, Level 1 [Member] |  |
Fair Value Measurements [Line Items] |  |
Assets: | 6,332 | 6,890
Money market funds | Cash equivalents: | Level 2 |  |
Fair Value Measurements [Line Items] |  |
Assets: | 0 | 0
U.S. government securities | Available-for-sale debt investments: |  |
Fair Value Measurements [Line Items] |  |
Assets: | 5,754 | 7,275
U.S. government securities | Available-for-sale debt investments: | Fair Value, Inputs, Level 1 [Member] |  |
Fair Value Measurements [Line Items] |  |
Assets: | 0 | 0
U.S. government securities | Available-for-sale debt investments: | Level 2 |  |
Fair Value Measurements [Line Items] |  |
Assets: | 5,754 | 7,275
U.S. government agency securities | Available-for-sale debt investments: |  |
Fair Value Measurements [Line Items] |  |
Assets: | 430 | 727
U.S. government agency securities | Available-for-sale debt investments: | Fair Value, Inputs, Level 1 [Member] |  |
Fair Value Measurements [Line Items] |  |
Assets: | 0 | 0
U.S. government agency securities | Available-for-sale debt investments: | Level 2 |  |
Fair Value Measurements [Line Items] |  |
Assets: | 430 | 727
Non-U.S. government and agency securities | Available-for-sale debt investments: |  |
Fair Value Measurements [Line Items] |  |
Assets: | 153 | 208
Non-U.S. government and agency securities | Available-for-sale debt investments: | Fair Value, Inputs, Level 1 [Member] |  |
Fair Value Measurements [Line Items] |  |
Assets: | 0 | 0
Non-U.S. government and agency securities | Available-for-sale debt investments: | Level 2 |  |
Fair Value Measurements [Line Items] |  |
Assets: | 153 | 208
Corporate debt securities | Available-for-sale debt investments: |  |
Fair Value Measurements [Line Items] |  |
Assets: | 26,031 | 27,364
Corporate debt securities | Available-for-sale debt investments: | Fair Value, Inputs, Level 1 [Member] |  |
Fair Value Measurements [Line Items] |  |
Assets: | 0 | 0
Corporate debt securities | Available-for-sale debt investments: | Level 2 |  |
Fair Value Measurements [Line Items] |  |
Assets: | 26,031 | 27,364
U.S. agency mortgage-backed securities | Available-for-sale debt investments: |  |
Fair Value Measurements [Line Items] |  |
Assets: | 1,421 | 1,435
U.S. agency mortgage-backed securities | Available-for-sale debt investments: | Fair Value, Inputs, Level 1 [Member] |  |
Fair Value Measurements [Line Items] |  |
Assets: | 0 | 0
U.S. agency mortgage-backed securities | Available-for-sale debt investments: | Level 2 |  |
Fair Value Measurements [Line Items] |  |
Assets: | 1,421 | 1,435
Commercial paper | Cash equivalents: |  |
Fair Value Measurements [Line Items] |  |
Assets: | 210 | 0
Commercial paper | Cash equivalents: | Fair Value, Inputs, Level 1 [Member] |  |
Fair Value Measurements [Line Items] |  |
Assets: | 0 | 0
Commercial paper | Cash equivalents: | Level 2 |  |
Fair Value Measurements [Line Items] |  |
Assets: | 210 | 0
Commercial paper | Available-for-sale debt investments: |  |
Fair Value Measurements [Line Items] |  |
Assets: | 309 | 0
Commercial paper | Available-for-sale debt investments: | Fair Value, Inputs, Level 1 [Member] |  |
Fair Value Measurements [Line Items] |  |
Assets: | 0 | 0
Commercial paper | Available-for-sale debt investments: | Level 2 |  |
Fair Value Measurements [Line Items] |  |
Assets: | 309 | 0
Certificates of deposit | Cash equivalents: |  |
Fair Value Measurements [Line Items] |  |
Assets: | 20 | 0
Certificates of deposit | Cash equivalents: | Fair Value, Inputs, Level 1 [Member] |  |
Fair Value Measurements [Line Items] |  |
Assets: | 0 | 0
Certificates of deposit | Cash equivalents: | Level 2 |  |
Fair Value Measurements [Line Items] |  |
Assets: | 20 | 0
Certificates of deposit | Available-for-sale debt investments: |  |
Fair Value Measurements [Line Items] |  |
Assets: | 85 | 0
Certificates of deposit | Available-for-sale debt investments: | Fair Value, Inputs, Level 1 [Member] |  |
Fair Value Measurements [Line Items] |  |
Assets: | 0 | 0
Certificates of deposit | Available-for-sale debt investments: | Level 2 |  |
Fair Value Measurements [Line Items] |  |
Assets: | 85 | 0
Repurchase agreements | Cash equivalents: |  |
Fair Value Measurements [Line Items] |  |
Assets: | 16 | 0
Repurchase agreements | Cash equivalents: | Fair Value, Inputs, Level 1 [Member] |  |
Fair Value Measurements [Line Items] |  |
Assets: | 0 | 0
Repurchase agreements | Cash equivalents: | Level 2 |  |
Fair Value Measurements [Line Items] |  |
Assets: | 16 | 0
Equity securities | Available-for-sale debt investments: |  |
Fair Value Measurements [Line Items] |  |
Assets: | 0 | 605
Equity securities | Available-for-sale debt investments: | Fair Value, Inputs, Level 1 [Member] |  |
Fair Value Measurements [Line Items] |  |
Assets: | 0 | 605
Equity securities | Available-for-sale debt investments: | Level 2 |  |
Fair Value Measurements [Line Items] |  |
Assets: | $ 0 | $ 0

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