v3.25.4

Claims, Lawsuits, and Other Contingencies - Legal Narrative (Details) - Fatal Plain Crash In November2016 - Pending Litigation $ in Millions	1 Months Ended					3 Months Ended
	Jun. 30, 2025 USD ($) plaintiff jurisdiction	Dec. 31, 2022 plaintiff	Aug. 31, 2020 USD ($) plaintiff	Nov. 30, 2019 USD ($) defendant	Nov. 30, 2018 USD ($)	Sep. 30, 2025 USD ($)	Dec. 31, 2023 USD ($)
Loss Contingencies [Line Items]
Value of damages sought	$ 16.7		$ 844.0		$ 16.0
Loss contingency, number of defendants \| defendant				3
Damages sought option 1				$ 300.0
Damages sought option 2				50.0
Damages sought option 3				$ 25.0
Loss contingency, number of plaintiffs \| plaintiff	43	43	43
Loss contingency, number of jurisdictions \| jurisdiction	3
Legal settlement expense						$ 23.0	$ 197.0

Loss Contingency Damages Sought Value Option One

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Loss Contingency Damages Sought Value Option Three

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Loss Contingency Damages Sought Value Option Two

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Loss Contingency, Number Of Jurisdictions

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- Definition

Amount of litigation expense, including but not limited to legal, forensic, accounting, and investigative fees.

+ References

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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.

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The value (monetary amount) of the award the plaintiff seeks in the legal matter.

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Number of defendants named in a legal action.

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Number of plaintiffs that have filed claims pertaining to a loss contingency.

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Aon plc 10-K