Financial Instruments - Schedule of marketable securities (Details) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | ||
---|---|---|---|---|
Oct. 31, 2022 |
Oct. 31, 2021 |
Oct. 31, 2022 |
Oct. 31, 2021 |
|
Investments, All Other Investments [Abstract] | ||||
Marketable debt securities | $ 57 | $ 0 | $ 302 | $ 4 |