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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 | 9 Months Ended |
--- | --- | --- | --- | ---
Apr. 25, 2024 | Sep. 30, 2024 | Sep. 30, 2023 | Sep. 30, 2024 | Sep. 30, 2023 | Dec. 31, 2023
Assets acquired: |  |  |  |  |  |
Goodwill |  | $ 15,612 |  | $ 15,612 |  | $ 8,414
Liabilities assumed: |  |  |  |  |  |
Funds held on behalf of clients |  | 7,940 | $ 7,230 | 7,940 | $ 7,230 |
2024 Acquisition |  |  |  |  |  |
Consideration transferred: |  |  |  |  |  |
Cash |  |  |  | 3,624 |  |
Deferred and contingent consideration |  |  |  | 19 |  |
Class A ordinary shares issued |  |  |  | 5,882 |  |
Aggregate consideration transferred |  |  |  | 9,525 |  |
Assets acquired: |  |  |  |  |  |
Cash and cash equivalents |  | 298 |  | 298 |  |
Receivables |  | 353 |  | 353 |  |
Fiduciary assets |  | 465 |  | 465 |  |
Goodwill |  | 7,192 |  | 7,192 |  |
Other intangible assets: |  |  |  |  |  |
Operating lease right-of-use assets |  | 144 |  | 144 |  |
Current assets |  | 9 |  | 9 |  |
Non-current assets |  | 171 |  | 171 |  |
Total assets acquired |  | 15,491 |  | 15,491 |  |
Liabilities assumed: |  |  |  |  |  |
Accounts payable and accrued liabilities |  | 315 |  | 315 |  |
Fiduciary liabilities |  | 465 |  | 465 |  |
Current liabilities |  | 234 |  | 234 |  |
Long-term debt |  | 3,422 |  | 3,422 |  |
Non-current operating lease liabilities |  | 128 |  | 128 |  |
Deferred tax liabilities |  | 1,062 |  | 1,062 |  |
Non-current liabilities |  | 147 |  | 147 |  |
Total liabilities assumed |  | 5,773 |  | 5,773 |  |
Less: Fair value of redeemable noncontrolling interests |  | (108) |  | (108) |  |
Less: Fair value of nonredeemable noncontrolling interests |  | (85) |  | (85) |  |
Net assets acquired |  | 9,525 |  | 9,525 |  |
Funds held on behalf of clients |  | 315 |  | 315 |  |
2024 Acquisition | Customer-related and contract-based |  |  |  |  |  |
Other intangible assets: |  |  |  |  |  |
Intangible assets |  | 6,032 |  | 6,032 |  |
2024 Acquisition | Tradenames |  |  |  |  |  |
Other intangible assets: |  |  |  |  |  |
Intangible assets |  | 801 |  | 801 |  |
2024 Acquisition | Technology and other |  |  |  |  |  |
Other intangible assets: |  |  |  |  |  |
Intangible assets |  | 26 |  | 26 |  |
NFP Acquisition |  |  |  |  |  |
Consideration transferred: |  |  |  |  |  |
Cash | $ 3,200 |  |  | 3,247 |  |
Deferred and contingent consideration |  |  |  | 0 |  |
Class A ordinary shares issued |  |  |  | 5,882 |  |
Aggregate consideration transferred | $ 9,100 |  |  | 9,129 |  |
Assets acquired: |  |  |  |  |  |
Cash and cash equivalents |  | 293 |  | 293 |  |
Receivables |  | 325 |  | 325 |  |
Fiduciary assets |  | 411 |  | 411 |  |
Goodwill |  | 6,987 |  | 6,987 |  |
Other intangible assets: |  |  |  |  |  |
Operating lease right-of-use assets |  | 140 |  | 140 |  |
Current assets |  | 3 |  | 3 |  |
Non-current assets |  | 169 |  | 169 |  |
Total assets acquired |  | 14,978 |  | 14,978 |  |
Liabilities assumed: |  |  |  |  |  |
Accounts payable and accrued liabilities |  | 283 |  | 283 |  |
Fiduciary liabilities |  | 411 |  | 411 |  |
Current liabilities |  | 232 |  | 232 |  |
Long-term debt |  | 3,422 |  | 3,422 |  |
Non-current operating lease liabilities |  | 125 |  | 125 |  |
Deferred tax liabilities |  | 1,038 |  | 1,038 |  |
Non-current liabilities |  | 145 |  | 145 |  |
Total liabilities assumed |  | 5,656 |  | 5,656 |  |
Less: Fair value of redeemable noncontrolling interests |  | (108) |  | (108) |  |
Less: Fair value of nonredeemable noncontrolling interests |  | (85) |  | (85) |  |
Net assets acquired |  | 9,129 |  | 9,129 |  |
NFP Acquisition | Customer-related and contract-based |  |  |  |  |  |
Other intangible assets: |  |  |  |  |  |
Intangible assets |  | 5,825 |  | 5,825 |  |
NFP Acquisition | Tradenames |  |  |  |  |  |
Other intangible assets: |  |  |  |  |  |
Intangible assets |  | 800 |  | 800 |  |
NFP Acquisition | Technology and other |  |  |  |  |  |
Other intangible assets: |  |  |  |  |  |
Intangible assets |  | 25 |  | 25 |  |
Other Acquisitions |  |  |  |  |  |
Consideration transferred: |  |  |  |  |  |
Cash |  |  |  | 377 |  |
Deferred and contingent consideration |  |  |  | 19 |  |
Class A ordinary shares issued |  |  |  | 0 |  |
Aggregate consideration transferred |  | 280 | $ 14 | 396 | $ 23 |
Assets acquired: |  |  |  |  |  |
Cash and cash equivalents |  | 5 |  | 5 |  |
Receivables |  | 28 |  | 28 |  |
Fiduciary assets |  | 54 |  | 54 |  |
Goodwill |  | 205 |  | 205 |  |
Other intangible assets: |  |  |  |  |  |
Operating lease right-of-use assets |  | 4 |  | 4 |  |
Current assets |  | 6 |  | 6 |  |
Non-current assets |  | 2 |  | 2 |  |
Total assets acquired |  | 513 |  | 513 |  |
Liabilities assumed: |  |  |  |  |  |
Accounts payable and accrued liabilities |  | 32 |  | 32 |  |
Fiduciary liabilities |  | 54 |  | 54 |  |
Current liabilities |  | 2 |  | 2 |  |
Long-term debt |  | 0 |  | 0 |  |
Non-current operating lease liabilities |  | 3 |  | 3 |  |
Deferred tax liabilities |  | 24 |  | 24 |  |
Non-current liabilities |  | 2 |  | 2 |  |
Total liabilities assumed |  | 117 |  | 117 |  |
Less: Fair value of redeemable noncontrolling interests |  | 0 |  | 0 |  |
Less: Fair value of nonredeemable noncontrolling interests |  | 0 |  | 0 |  |
Net assets acquired |  | 396 |  | 396 |  |
Other Acquisitions | Customer-related and contract-based |  |  |  |  |  |
Other intangible assets: |  |  |  |  |  |
Intangible assets |  | 207 |  | 207 |  |
Other Acquisitions | Tradenames |  |  |  |  |  |
Other intangible assets: |  |  |  |  |  |
Intangible assets |  | 1 |  | 1 |  |
Other Acquisitions | Technology and other |  |  |  |  |  |
Other intangible assets: |  |  |  |  |  |
Intangible assets |  | $ 1 |  | $ 1 |  |

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