Marketable Securities (Details) - USD ($) $ in Millions	Apr. 29, 2018	Jan. 28, 2018
Summary of cash equivalents and marketable securities:
Amortized Cost	$ 7,118	$ 6,916
Unrealized Gain	2	2
Unrealized Loss	(25)	(23)
Classified as:
Cash equivalents	560	3,789
Marketable securities	6,535	3,106
Total cash equivalents and marketable securities	7,095	6,895
Amortized Cost
Less than one year	5,490	5,381
Due in 1-5 years	1,593	1,500
Mortgage-backed securities issued by government-sponsored enterprises not due to a single maturity date	35	35
Total	7,118	6,916
Estimated Fair Value
Less than one year	5,481	5,375
Due in 1-5 years	1,578	1,485
Mortgage-backed securities issued by United States government-sponsored enterprises not due to a single maturity date	36	35
Total	7,095	6,895
Fair value, unrealized loss position
Fair value, unrealized loss less than 12 months	2,887
Fair value, unrealized loss greater than 12 months	2,196
Fair value with unrealized loss, total	5,083
Unrealized Loss Position, Aggregate Losses
Unrealized loss, less than 12 months, gross	(4)
Unrealized loss, 12 months or greater, gross	(21)
Gross unrealized loss, total	(25)
Corporate debt securities
Summary of cash equivalents and marketable securities:
Amortized Cost	1,803	1,304
Unrealized Gain	0	0
Unrealized Loss	(11)	(9)
Classified as:
Cash equivalents	0	0
Marketable securities	1,792	1,295
Total cash equivalents and marketable securities	1,792	1,295
Fair value, unrealized loss position
Fair value, unrealized loss less than 12 months	253
Fair value, unrealized loss greater than 12 months	835
Fair value with unrealized loss, total	1,088
Unrealized Loss Position, Aggregate Losses
Unrealized loss, less than 12 months, gross	(2)
Unrealized loss, 12 months or greater, gross	(9)
Gross unrealized loss, total	(11)
Debt securities of United States government agencies
Summary of cash equivalents and marketable securities:
Amortized Cost	1,734	822
Unrealized Gain	0	0
Unrealized Loss	(7)	(7)
Classified as:
Cash equivalents	0	0
Marketable securities	1,727	815
Total cash equivalents and marketable securities	1,727	815
Fair value, unrealized loss position
Fair value, unrealized loss less than 12 months	1,039
Fair value, unrealized loss greater than 12 months	687
Fair value with unrealized loss, total	1,726
Unrealized Loss Position, Aggregate Losses
Unrealized loss, less than 12 months, gross	(1)
Unrealized loss, 12 months or greater, gross	(6)
Gross unrealized loss, total	(7)
Debt securities issued by the United States Treasury
Summary of cash equivalents and marketable securities:
Amortized Cost	2,741	577
Unrealized Gain	0	0
Unrealized Loss	(4)	(4)
Classified as:
Cash equivalents	100	0
Marketable securities	2,637	573
Total cash equivalents and marketable securities	2,737	573
Fair value, unrealized loss position
Fair value, unrealized loss less than 12 months	1,539
Fair value, unrealized loss greater than 12 months	502
Fair value with unrealized loss, total	2,041
Unrealized Loss Position, Aggregate Losses
Unrealized loss, less than 12 months, gross	0
Unrealized loss, 12 months or greater, gross	(4)
Gross unrealized loss, total	(4)
Asset-backed Securities
Summary of cash equivalents and marketable securities:
Amortized Cost	230	254
Unrealized Gain	0	0
Unrealized Loss	(3)	(2)
Classified as:
Cash equivalents	0	0
Marketable securities	227	252
Total cash equivalents and marketable securities	227	252
Fair value, unrealized loss position
Fair value, unrealized loss less than 12 months	56
Fair value, unrealized loss greater than 12 months	172
Fair value with unrealized loss, total	228
Unrealized Loss Position, Aggregate Losses
Unrealized loss, less than 12 months, gross	(1)
Unrealized loss, 12 months or greater, gross	(2)
Gross unrealized loss, total	(3)
Mortgage backed securities issued by United States government-sponsored enterprises
Summary of cash equivalents and marketable securities:
Amortized Cost	119	128
Unrealized Gain	2	2
Unrealized Loss	0	0
Classified as:
Cash equivalents	0	0
Marketable securities	121	130
Total cash equivalents and marketable securities	121	130
Foreign government bonds
Summary of cash equivalents and marketable securities:
Amortized Cost	31	42
Unrealized Gain	0	0
Unrealized Loss	0	(1)
Classified as:
Cash equivalents	0	0
Marketable securities	31	41
Total cash equivalents and marketable securities	31	41
Money market funds
Summary of cash equivalents and marketable securities:
Amortized Cost	460	3,789
Unrealized Gain	0	0
Unrealized Loss	0	0
Classified as:
Cash equivalents	460	3,789
Marketable securities	0	0
Total cash equivalents and marketable securities	$ 460	$ 3,789