Fair Value of Financial Assets and Liabilities (Details) - USD ($) $ in Millions	Apr. 26, 2020	Mar. 31, 2020	Jan. 26, 2020	Sep. 30, 2016
Assets
Cash equivalents and marketable securities	$ 16,199		$ 10,781
2.20% Notes Due 2021
Liabilities
Stated interest rate	2.20%			2.20%
3.20% Notes Due 2026
Liabilities
Stated interest rate	3.20%			3.20%
2.85% Notes Due 2030
Liabilities
Stated interest rate	2.85%	2.85%
3.50% Notes Due 2040
Liabilities
Stated interest rate	3.50%	3.50%
3.50% Notes Due 2050
Liabilities
Stated interest rate	3.50%	3.50%
3.70% Notes Due 2060
Liabilities
Stated interest rate	3.70%	3.70%
Money market funds
Assets
Cash equivalents and marketable securities	$ 11,128		7,507
Corporate debt securities
Assets
Cash equivalents and marketable securities	3,238		592
Foreign government bonds
Assets
Cash equivalents and marketable securities	870		200
Certificates of deposit
Assets
Cash equivalents and marketable securities	582		27
Debt securities issued by United States government agencies
Assets
Cash equivalents and marketable securities	381		1,096
Debt securities issued by the United States Treasury
Assets
Cash equivalents and marketable securities			1,358
Asset-backed securities
Assets
Cash equivalents and marketable securities			1
Fair Value, Inputs, Level 1 | Money market funds
Assets
Cash equivalents and marketable securities	11,128		7,507
Fair Value, Inputs, Level 2 | 2.20% Notes Due 2021
Liabilities
Notes	1,020		1,065
Fair Value, Inputs, Level 2 | 3.20% Notes Due 2026
Liabilities
Notes	1,104		1,006
Fair Value, Inputs, Level 2 | 2.85% Notes Due 2030
Liabilities
Notes	1,635		0
Fair Value, Inputs, Level 2 | 3.50% Notes Due 2040
Liabilities
Notes	1,134		0
Fair Value, Inputs, Level 2 | 3.50% Notes Due 2050
Liabilities
Notes	2,336		0
Fair Value, Inputs, Level 2 | 3.70% Notes Due 2060
Liabilities
Notes	594		0
Fair Value, Inputs, Level 2 | Corporate debt securities
Assets
Cash equivalents and marketable securities	3,238		592
Fair Value, Inputs, Level 2 | Foreign government bonds
Assets
Cash equivalents and marketable securities	870		200
Fair Value, Inputs, Level 2 | Certificates of deposit
Assets
Cash equivalents and marketable securities	582		27
Fair Value, Inputs, Level 2 | Debt securities issued by United States government agencies
Assets
Cash equivalents and marketable securities	381		1,096
Fair Value, Inputs, Level 2 | Debt securities issued by the United States Treasury
Assets
Cash equivalents and marketable securities	0		1,358
Fair Value, Inputs, Level 2 | Asset-backed securities
Assets
Cash equivalents and marketable securities	$ 0		$ 1