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Acquisitions and Dispositions (Acquired Finite-Lived Intangible Assets) (Details) $ in Millions | 9 Months Ended
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Sep. 30, 2019 USD ($)
Finite-Lived Intangible Assets [Line Items] |
Finite-lived intangible assets acquired | $ 1,756
Client relationships |
Finite-Lived Intangible Assets [Line Items] |
Finite-lived intangible assets acquired | 1,647
Other |
Finite-Lived Intangible Assets [Line Items] |
Finite-lived intangible assets acquired | 109
Jardine Lloyd Thompson Group plc |
Finite-Lived Intangible Assets [Line Items] |
Finite-lived intangible assets acquired | 1,613
Jardine Lloyd Thompson Group plc | Client relationships |
Finite-Lived Intangible Assets [Line Items] |
Finite-lived intangible assets acquired | $ 1,511
Finite-lived intangible assets, remaining amortization period | 13 years
Jardine Lloyd Thompson Group plc | Other |
Finite-Lived Intangible Assets [Line Items] |
Finite-lived intangible assets acquired | $ 102
Finite-lived intangible assets, remaining amortization period | 4 years
Other |
Finite-Lived Intangible Assets [Line Items] |
Finite-lived intangible assets acquired | $ 143
Other | Client relationships |
Finite-Lived Intangible Assets [Line Items] |
Finite-lived intangible assets acquired | $ 136
Finite-lived intangible assets, remaining amortization period | 12 years
Other | Other |
Finite-Lived Intangible Assets [Line Items] |
Finite-lived intangible assets acquired | $ 7
Finite-lived intangible assets, remaining amortization period | 3 years

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- Definition Remaining amortization period of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
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- Definition Amount of increase in assets, excluding financial assets, lacking physical substance with a definite life, from an acquisition. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 50 -Paragraph 1 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16265-109275 + Details
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