Deferred Compensation (Details) - USD ($) |
3 Months Ended | 9 Months Ended | |||
|---|---|---|---|---|---|
Oct. 31, 2022 |
Oct. 31, 2021 |
Oct. 31, 2022 |
Oct. 31, 2021 |
Jan. 31, 2022 |
|
| Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items] | |||||
| Costs to obtain a contract | $ 105,000,000 | $ 105,000,000 | $ 139,000,000 | ||
| Amortization of costs to obtain a contract | 35,000,000 | $ 30,000,000 | 102,000,000 | $ 84,000,000 | |
| Impairment loss | 0 | $ 0 | 0 | $ 0 | |
| Rabbi Trust | |||||
| Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items] | |||||
| Deferred compensation liability | 82,000,000 | 82,000,000 | 89,000,000 | ||
| Deferred compensation liability, current | 7,000,000 | 7,000,000 | 7,000,000 | ||
| Deferred compensation liability, non-current | $ 75,000,000 | $ 75,000,000 | $ 82,000,000 | ||