Marketable Securities (Details) - USD ($) $ in Millions	Jul. 30, 2017	Jan. 29, 2017
Summary of cash equivalents and marketable securities:
Amortized Cost	$ 5,562	$ 5,484
Unrealized Gain	3	3
Unrealized Loss	(13)	(19)
Classified as:
Cash equivalents	1,663	436
Marketable securities	3,889	5,032
Total cash equivalents and marketable securities	5,552	5,468
Amortized Cost
Less than one year	3,086	2,209
Due in 1-5 years	2,423	3,210
Mortgage-backed securities issued by government-sponsored enterprises not due to a single maturity date	53	65
Total	5,562	5,484
Estimated Fair Value
Less than one year	3,085	2,209
Due in 1-5 years	2,414	3,194
Mortgage-backed securities issued by United States government-sponsored enterprises not due to a single maturity date	53	65
Total	5,552	5,468
Fair value, unrealized loss position
Fair value, unrealized loss less than 12 months	3,113
Fair value, unrealized loss greater than 12 months	222
Fair value with unrealized loss, total	3,335
Unrealized Loss Position, Aggregate Losses
Unrealized loss, less than 12 months, gross	(10)
Unrealized loss, 12 months or greater, gross	(3)
Gross unrealized loss, total	(13)
Corporate debt securities
Summary of cash equivalents and marketable securities:
Amortized Cost	1,664	2,397
Unrealized Gain	1	1
Unrealized Loss	(5)	(10)
Classified as:
Cash equivalents	0	33
Marketable securities	1,660	2,355
Total cash equivalents and marketable securities	1,660	2,388
Fair value, unrealized loss position
Fair value, unrealized loss less than 12 months	1,243
Fair value, unrealized loss greater than 12 months	86
Fair value with unrealized loss, total	1,329
Unrealized Loss Position, Aggregate Losses
Unrealized loss, less than 12 months, gross	(4)
Unrealized loss, 12 months or greater, gross	(1)
Gross unrealized loss, total	(5)
Debt securities of United States government agencies
Summary of cash equivalents and marketable securities:
Amortized Cost	1,030	1,193
Unrealized Gain	0	0
Unrealized Loss	(4)	(5)
Classified as:
Cash equivalents	0	27
Marketable securities	1,026	1,161
Total cash equivalents and marketable securities	1,026	1,188
Fair value, unrealized loss position
Fair value, unrealized loss less than 12 months	881
Fair value, unrealized loss greater than 12 months	100
Fair value with unrealized loss, total	981
Unrealized Loss Position, Aggregate Losses
Unrealized loss, less than 12 months, gross	(3)
Unrealized loss, 12 months or greater, gross	(1)
Gross unrealized loss, total	(4)
Debt securities issued by the United States Treasury
Summary of cash equivalents and marketable securities:
Amortized Cost	658	852
Unrealized Gain	0	0
Unrealized Loss	(2)	(2)
Classified as:
Cash equivalents	0	55
Marketable securities	656	795
Total cash equivalents and marketable securities	656	850
Fair value, unrealized loss position
Fair value, unrealized loss less than 12 months	645
Fair value, unrealized loss greater than 12 months	0
Fair value with unrealized loss, total	645
Unrealized Loss Position, Aggregate Losses
Unrealized loss, less than 12 months, gross	(2)
Unrealized loss, 12 months or greater, gross	0
Gross unrealized loss, total	(2)
Asset-backed Securities
Summary of cash equivalents and marketable securities:
Amortized Cost	330	490
Unrealized Gain	0	0
Unrealized Loss	(1)	(1)
Classified as:
Cash equivalents	0	0
Marketable securities	329	489
Total cash equivalents and marketable securities	329	489
Fair value, unrealized loss position
Fair value, unrealized loss less than 12 months	304
Fair value, unrealized loss greater than 12 months	0
Fair value with unrealized loss, total	304
Unrealized Loss Position, Aggregate Losses
Unrealized loss, less than 12 months, gross	(1)
Unrealized loss, 12 months or greater, gross	0
Gross unrealized loss, total	(1)
Mortgage backed securities issued by United States government-sponsored enterprises
Summary of cash equivalents and marketable securities:
Amortized Cost	153	161
Unrealized Gain	2	2
Unrealized Loss	(1)	(1)
Classified as:
Cash equivalents	0	0
Marketable securities	154	162
Total cash equivalents and marketable securities	154	162
Fair value, unrealized loss position
Fair value, unrealized loss less than 12 months	40
Fair value, unrealized loss greater than 12 months	36
Fair value with unrealized loss, total	76
Unrealized Loss Position, Aggregate Losses
Unrealized loss, less than 12 months, gross	0
Unrealized loss, 12 months or greater, gross	(1)
Gross unrealized loss, total	(1)
Foreign government bonds
Summary of cash equivalents and marketable securities:
Amortized Cost	64	70
Unrealized Gain	0	0
Unrealized Loss	0	0
Classified as:
Cash equivalents	0	0
Marketable securities	64	70
Total cash equivalents and marketable securities	64	70
Money market funds
Summary of cash equivalents and marketable securities:
Amortized Cost	1,663	321
Unrealized Gain	0	0
Unrealized Loss	0	0
Classified as:
Cash equivalents	1,663	321
Marketable securities	0	0
Total cash equivalents and marketable securities	$ 1,663	$ 321