Goodwill and Intangible Assets - Schedule of Goodwill by Segment (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Goodwill [Line Items]
Goodwill	$ 1,250.7	$ 1,250.7
Specialty Property & Casualty Insurance
Goodwill [Line Items]
Goodwill	1,043.0	1,043.0
Life Insurance
Goodwill [Line Items]
Goodwill	$ 207.7	$ 207.7

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.

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+ Details

- 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.

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