Goodwill and Intangible Assets - Goodwill Rollforward (Details) $ in Millions	3 Months Ended
Mar. 31, 2022 USD ($)
Goodwill
Beginning balance	$ 43.5
Impairment	0.0
Acquisition	12.8
Ending balance	56.3
Property & Casualty
Goodwill
Beginning balance	9.5
Impairment	0.0
Acquisition	0.0
Ending balance	9.5
Life & Retirement
Goodwill
Beginning balance	14.4
Impairment	0.0
Acquisition	0.0
Ending balance	14.4
Supplemental & Group Benefits
Goodwill
Beginning balance	19.6
Impairment	0.0
Acquisition	12.8
Ending balance	$ 32.4

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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