Goodwill and Other Intangibles (Narrative) (Details) - USD ($) |
3 Months Ended | 6 Months Ended | ||||
|---|---|---|---|---|---|---|
Jun. 30, 2024 |
Jun. 30, 2023 |
Jun. 30, 2024 |
Jun. 30, 2023 |
Dec. 31, 2023 |
Dec. 31, 2022 |
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| Segment Reporting Information [Line Items] | ||||||
| Indefinite-lived intangible assets | $ 0 | $ 0 | $ 0 | |||
| Goodwill | 17,516,000,000 | $ 16,621,000,000 | 17,516,000,000 | $ 16,621,000,000 | $ 17,231,000,000 | $ 16,251,000,000 |
| Aggregate amortization expense | 89,000,000 | $ 87,000,000 | 179,000,000 | $ 172,000,000 | ||
| Risk and Insurance Services | ||||||
| Segment Reporting Information [Line Items] | ||||||
| Goodwill expected to be tax deductible | 254,000,000 | 254,000,000 | ||||
| Goodwill | 13,400,000,000 | 13,400,000,000 | ||||
| Consulting | ||||||
| Segment Reporting Information [Line Items] | ||||||
| Goodwill expected to be tax deductible | 81,000,000 | 81,000,000 | ||||
| Goodwill | $ 4,100,000,000 | $ 4,100,000,000 | ||||
| X | ||||||||||
- Definition The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition The amount of goodwill arising from a business combination that is expected to be deductible for tax purposes. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Amount, after accumulated impairment loss, of asset representing future economic benefit arising from other asset acquired in business combination or from joint venture formation or both, that is not individually identified and separately recognized. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount of assets, excluding financial assets and goodwill, lacking physical substance and having a projected indefinite period of benefit. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
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