Costs to Obtain a Contract with a Customer (Details) - USD ($) |
3 Months Ended | 6 Months Ended | |||
|---|---|---|---|---|---|
Jul. 31, 2026 |
Jul. 31, 2025 |
Jul. 31, 2026 |
Jul. 31, 2025 |
Jan. 31, 2026 |
|
| Capitalized Contract Cost [Line Items] | |||||
| Costs to obtain a contract | $ 794,000,000 | $ 794,000,000 | $ 913,000,000 | ||
| Current liability | 368,000,000 | 368,000,000 | $ 550,000,000 | ||
| Amortization of costs to obtain a contract with a customer | $ 123,000,000 | 347,000,000 | $ 219,000,000 | ||
| Impairment losses | 0 | $ 0 | 0 | $ 0 | |
| Revision of Prior Period, Reclassification, Adjustment | |||||
| Capitalized Contract Cost [Line Items] | |||||
| Amortization of costs to obtain a contract with a customer | $ 175,000,000 | $ 347,000,000 | |||