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Accounting Policies - Narrative (Details) - USD ($) $ in Millions | 12 Months Ended
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Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021
Significant Accounting Policies [Line Items] |  |  |
Assets of managed investment entities | $ 4,484 | $ 5,447 |
Liabilities of managed investment entities | $ 4,307 | $ 5,332 |
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List] | Other Liabilities | Other Liabilities |
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration] | Other Assets | Other Assets |
Weighted average common shares adjustment related to stock-based compensation | 100,000 | 200,000 | 500,000
Anti-dilutive potential common shares related to stock-based compensation plans | 0 | 0 | 0
Maturities of short term investments | 3 months |  |
New collateralized loan obligation, temporary warehousing entities |  |  |
Significant Accounting Policies [Line Items] |  |  |
Assets of managed investment entities | $ 263 |  |
Liabilities of managed investment entities | $ 225 |  |

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