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Acquisitions and Dispositions of Businesses - Schedule of Consideration Transferred and Preliminary Value of Intangible Assets (Details) - USD ($) $ in Millions |  | 3 Months Ended |  |
--- | --- | --- | --- | ---
Apr. 25, 2024 | Mar. 31, 2025 | Dec. 31, 2024 | Mar. 31, 2024
Assets acquired: |  |  |  |
Goodwill |  | $ 15,697 | $ 15,234 |
Liabilities assumed: |  |  |  |
Payments to acquire businesses, escrow deposits |  |  | $ 416 |
Funds held on behalf of clients |  | 7,062 |  | $ 7,117
2024 Acquisition |  |  |  |
Liabilities assumed: |  |  |  |
Funds held on behalf of clients |  | 277 |  |
NFP Acquisition |  |  |  |
Consideration transferred: |  |  |  |
Cash | $ 3,200 | 3,247 |  |
Class A ordinary shares issued |  | 5,882 |  |
Aggregate consideration transferred | $ 9,100 | 9,129 |  |
Assets acquired: |  |  |  |
Cash and cash equivalents |  | 294 |  |
Receivables |  | 329 |  |
Fiduciary assets |  | 411 |  |
Goodwill |  | 6,847 |  |
Other intangible assets: |  |  |  |
Operating lease right-of-use assets |  | 138 |  |
Current assets |  | 82 |  |
Non-current assets |  | 108 |  |
Total assets acquired |  | 14,984 |  |
Liabilities assumed: |  |  |  |
Accounts payable and accrued liabilities |  | 284 |  |
Fiduciary liabilities |  | 411 |  |
Current liabilities |  | 242 |  |
Long-term debt |  | 3,422 |  |
Non-current operating lease liabilities |  | 125 |  |
Deferred tax liabilities |  | 1,020 |  |
Non-current liabilities |  | 158 |  |
Total liabilities assumed |  | 5,662 |  |
Less: Fair value of redeemable noncontrolling interests |  | (108) |  |
Less: Fair value of nonredeemable noncontrolling interests |  | (85) |  |
Net assets acquired |  | 9,129 |  |
NFP Acquisition | Customer-related and contract-based |  |  |  |
Other intangible assets: |  |  |  |
Intangible assets |  | 5,950 |  |
NFP Acquisition | Tradenames |  |  |  |
Other intangible assets: |  |  |  |
Intangible assets |  | 800 |  |
NFP Acquisition | Technology and other |  |  |  |
Other intangible assets: |  |  |  |
Intangible assets |  | 25 |  |
2025 Acquisitions |  |  |  |
Consideration transferred: |  |  |  |
Cash |  | 605 |  |
Deferred and contingent consideration |  | 35 |  |
Aggregate consideration transferred |  | 640 |  |
Assets acquired: |  |  |  |
Cash and cash equivalents |  | 33 |  |
Goodwill |  | 351 |  |
Intangible assets |  | 299 |  |
Other intangible assets: |  |  |  |
Other assets |  | 125 |  |
Total assets acquired |  | 775 |  |
Liabilities assumed: |  |  |  |
Total liabilities assumed |  | 135 |  |
Net assets acquired |  | 640 |  |
Funds held on behalf of clients |  | $ 41 |  |

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