Marketable Securities (Details) - USD ($) | 3 Months Ended | 6 Months Ended | |
Jul. 29, 2018 | Jul. 30, 2017 | Jul. 29, 2018 | Jul. 30, 2017 | Jan. 28, 2018 |
Summary of cash equivalents and marketable securities: | | | | | |
Unrealized Gain | $ 3,000,000 | | $ 3,000,000 | | $ 2,000,000 |
Unrealized Loss | (19,000,000) | | (19,000,000) | | (23,000,000) |
Reported as | | | | | |
Cash Equivalents | 483,000,000 | | 483,000,000 | | 3,789,000,000 |
Marketable Securities | 7,225,000,000 | | 7,225,000,000 | | 3,106,000,000 |
Fair value, unrealized loss position | | | | | |
Fair value, unrealized loss less than 12 months | 2,053,000,000 | | 2,053,000,000 | | |
Fair value, unrealized loss greater than 12 months | 1,928,000,000 | | 1,928,000,000 | | |
Fair value with unrealized loss, total | 3,981,000,000 | | 3,981,000,000 | | |
Unrealized Loss Position, Aggregate Losses | | | | | |
Unrealized loss, less than 12 months, gross | (3,000,000) | | (3,000,000) | | |
Unrealized loss, 12 months or greater, gross | (16,000,000) | | (16,000,000) | | |
Gross unrealized loss, total | (19,000,000) | | (19,000,000) | | |
Other-than-temporary impairment losses | 0 | $ 0 | 0 | $ 0 | |
Amortized Cost | | | | | |
Less than 1 year | 5,991,000,000 | | 5,991,000,000 | | 5,381,000,000 |
Due in 1 - 5 years | 1,705,000,000 | | 1,705,000,000 | | 1,500,000,000 |
Mortgage-backed securities issued by United States government-sponsored enterprises not due at a single maturity date | 28,000,000 | | 28,000,000 | | 35,000,000 |
Amortized Cost | 7,724,000,000 | | 7,724,000,000 | | 6,916,000,000 |
Estimated Fair Value | | | | | |
Less than 1 year | 5,981,000,000 | | 5,981,000,000 | | 5,375,000,000 |
Due in 1 - 5 years | 1,699,000,000 | | 1,699,000,000 | | 1,485,000,000 |
Mortgage-backed securities issued by United States government-sponsored enterprises not due at a single maturity date | 28,000,000 | | 28,000,000 | | 35,000,000 |
Estimated Fair Value | 7,708,000,000 | | 7,708,000,000 | | 6,895,000,000 |
Corporate debt securities | | | | | |
Summary of cash equivalents and marketable securities: | | | | | |
Unrealized Gain | 1,000,000 | | 1,000,000 | | 0 |
Unrealized Loss | (8,000,000) | | (8,000,000) | | (9,000,000) |
Reported as | | | | | |
Cash Equivalents | 0 | | 0 | | 0 |
Marketable Securities | 2,484,000,000 | | 2,484,000,000 | | 1,295,000,000 |
Fair value, unrealized loss position | | | | | |
Fair value, unrealized loss less than 12 months | 310,000,000 | | 310,000,000 | | |
Fair value, unrealized loss greater than 12 months | 742,000,000 | | 742,000,000 | | |
Fair value with unrealized loss, total | 1,052,000,000 | | 1,052,000,000 | | |
Unrealized Loss Position, Aggregate Losses | | | | | |
Unrealized loss, less than 12 months, gross | (1,000,000) | | (1,000,000) | | |
Unrealized loss, 12 months or greater, gross | (7,000,000) | | (7,000,000) | | |
Gross unrealized loss, total | (8,000,000) | | (8,000,000) | | |
Amortized Cost | | | | | |
Amortized Cost | 2,491,000,000 | | 2,491,000,000 | | 1,304,000,000 |
Estimated Fair Value | | | | | |
Estimated Fair Value | 2,484,000,000 | | 2,484,000,000 | | 1,295,000,000 |
Debt securities issued by the United States Treasury | | | | | |
Summary of cash equivalents and marketable securities: | | | | | |
Unrealized Gain | 0 | | 0 | | 0 |
Unrealized Loss | (2,000,000) | | (2,000,000) | | (4,000,000) |
Reported as | | | | | |
Cash Equivalents | 0 | | 0 | | 0 |
Marketable Securities | 2,410,000,000 | | 2,410,000,000 | | 573,000,000 |
Fair value, unrealized loss position | | | | | |
Fair value, unrealized loss less than 12 months | 754,000,000 | | 754,000,000 | | |
Fair value, unrealized loss greater than 12 months | 410,000,000 | | 410,000,000 | | |
Fair value with unrealized loss, total | 1,164,000,000 | | 1,164,000,000 | | |
Unrealized Loss Position, Aggregate Losses | | | | | |
Unrealized loss, less than 12 months, gross | 0 | | 0 | | |
Unrealized loss, 12 months or greater, gross | (2,000,000) | | (2,000,000) | | |
Gross unrealized loss, total | (2,000,000) | | (2,000,000) | | |
Amortized Cost | | | | | |
Amortized Cost | 2,412,000,000 | | 2,412,000,000 | | 577,000,000 |
Estimated Fair Value | | | | | |
Estimated Fair Value | 2,410,000,000 | | 2,410,000,000 | | 573,000,000 |
Debt securities of United States government agencies | | | | | |
Summary of cash equivalents and marketable securities: | | | | | |
Unrealized Gain | 0 | | 0 | | 0 |
Unrealized Loss | (6,000,000) | | (6,000,000) | | (7,000,000) |
Reported as | | | | | |
Cash Equivalents | 0 | | 0 | | 0 |
Marketable Securities | 1,987,000,000 | | 1,987,000,000 | | 815,000,000 |
Fair value, unrealized loss position | | | | | |
Fair value, unrealized loss less than 12 months | 925,000,000 | | 925,000,000 | | |
Fair value, unrealized loss greater than 12 months | 559,000,000 | | 559,000,000 | | |
Fair value with unrealized loss, total | 1,484,000,000 | | 1,484,000,000 | | |
Unrealized Loss Position, Aggregate Losses | | | | | |
Unrealized loss, less than 12 months, gross | (1,000,000) | | (1,000,000) | | |
Unrealized loss, 12 months or greater, gross | (5,000,000) | | (5,000,000) | | |
Gross unrealized loss, total | (6,000,000) | | (6,000,000) | | |
Amortized Cost | | | | | |
Amortized Cost | 1,993,000,000 | | 1,993,000,000 | | 822,000,000 |
Estimated Fair Value | | | | | |
Estimated Fair Value | 1,987,000,000 | | 1,987,000,000 | | 815,000,000 |
Money market funds | | | | | |
Summary of cash equivalents and marketable securities: | | | | | |
Unrealized Gain | 0 | | 0 | | 0 |
Unrealized Loss | 0 | | 0 | | 0 |
Reported as | | | | | |
Cash Equivalents | 483,000,000 | | 483,000,000 | | 3,789,000,000 |
Marketable Securities | 0 | | 0 | | 0 |
Amortized Cost | | | | | |
Amortized Cost | 483,000,000 | | 483,000,000 | | 3,789,000,000 |
Estimated Fair Value | | | | | |
Estimated Fair Value | 483,000,000 | | 483,000,000 | | 3,789,000,000 |
Asset-backed securities | | | | | |
Summary of cash equivalents and marketable securities: | | | | | |
Unrealized Gain | 0 | | 0 | | 0 |
Unrealized Loss | (2,000,000) | | (2,000,000) | | (2,000,000) |
Reported as | | | | | |
Cash Equivalents | 0 | | 0 | | 0 |
Marketable Securities | 204,000,000 | | 204,000,000 | | 252,000,000 |
Fair value, unrealized loss position | | | | | |
Fair value, unrealized loss less than 12 months | 49,000,000 | | 49,000,000 | | |
Fair value, unrealized loss greater than 12 months | 155,000,000 | | 155,000,000 | | |
Fair value with unrealized loss, total | 204,000,000 | | 204,000,000 | | |
Unrealized Loss Position, Aggregate Losses | | | | | |
Unrealized loss, less than 12 months, gross | (1,000,000) | | (1,000,000) | | |
Unrealized loss, 12 months or greater, gross | (1,000,000) | | (1,000,000) | | |
Gross unrealized loss, total | (2,000,000) | | (2,000,000) | | |
Amortized Cost | | | | | |
Amortized Cost | 206,000,000 | | 206,000,000 | | 254,000,000 |
Estimated Fair Value | | | | | |
Estimated Fair Value | 204,000,000 | | 204,000,000 | | 252,000,000 |
Mortgage-backed securities issued by United States government-sponsored enterprises | | | | | |
Summary of cash equivalents and marketable securities: | | | | | |
Unrealized Gain | 2,000,000 | | 2,000,000 | | 2,000,000 |
Unrealized Loss | (1,000,000) | | (1,000,000) | | 0 |
Reported as | | | | | |
Cash Equivalents | 0 | | 0 | | 0 |
Marketable Securities | 108,000,000 | | 108,000,000 | | 130,000,000 |
Fair value, unrealized loss position | | | | | |
Fair value, unrealized loss less than 12 months | 15,000,000 | | 15,000,000 | | |
Fair value, unrealized loss greater than 12 months | 31,000,000 | | 31,000,000 | | |
Fair value with unrealized loss, total | 46,000,000 | | 46,000,000 | | |
Unrealized Loss Position, Aggregate Losses | | | | | |
Unrealized loss, less than 12 months, gross | 0 | | 0 | | |
Unrealized loss, 12 months or greater, gross | (1,000,000) | | (1,000,000) | | |
Gross unrealized loss, total | (1,000,000) | | (1,000,000) | | |
Amortized Cost | | | | | |
Amortized Cost | 107,000,000 | | 107,000,000 | | 128,000,000 |
Estimated Fair Value | | | | | |
Estimated Fair Value | 108,000,000 | | 108,000,000 | | 130,000,000 |
Foreign government bonds | | | | | |
Summary of cash equivalents and marketable securities: | | | | | |
Unrealized Gain | 0 | | 0 | | 0 |
Unrealized Loss | 0 | | 0 | | (1,000,000) |
Reported as | | | | | |
Cash Equivalents | 0 | | 0 | | 0 |
Marketable Securities | 32,000,000 | | 32,000,000 | | 41,000,000 |
Fair value, unrealized loss position | | | | | |
Fair value, unrealized loss less than 12 months | 0 | | 0 | | |
Fair value, unrealized loss greater than 12 months | 31,000,000 | | 31,000,000 | | |
Fair value with unrealized loss, total | 31,000,000 | | 31,000,000 | | |
Unrealized Loss Position, Aggregate Losses | | | | | |
Unrealized loss, less than 12 months, gross | 0 | | 0 | | |
Unrealized loss, 12 months or greater, gross | 0 | | 0 | | |
Gross unrealized loss, total | 0 | | 0 | | |
Amortized Cost | | | | | |
Amortized Cost | 32,000,000 | | 32,000,000 | | 42,000,000 |
Estimated Fair Value | | | | | |
Estimated Fair Value | $ 32,000,000 | | $ 32,000,000 | | $ 41,000,000 |