Employee Benefit Plans - 401(k) and Defined Contribution Pension Plans (Details) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
Dec. 31, 2023 |
|
| Morgan Stanley 401(k) Plan | |||
| Defined Contribution Plans | |||
| Expense | $ 414 | $ 400 | $ 397 |
| Non-U.S. Defined Contribution Pension Plans | |||
| Defined Contribution Plans | |||
| Expense | $ 193 | $ 181 | $ 173 |