Goodwill and Intangible Assets - Narrative (Details) - USD ($) $ in Millions		12 Months Ended
	Oct. 01, 2022	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Goodwill [Line Items]
Goodwill impairment		$ 0.0	$ 0.0	$ 2.0
Impairment of infinite lived intangible assets		$ 0.0	0.0	0.3
Impairment, Intangible Asset, Finite-Lived, Statement of Income or Comprehensive Income [Extensible Enumeration]		Other expense - goodwill and intangible asset impairments
Trade Names
Goodwill [Line Items]
Impairment of infinite lived intangible assets		$ 0.0	$ 0.0	$ 0.3
Benefit Consultants Group Inc.
Goodwill [Line Items]
Intangible assets		9.1
Benefit Consultants Group Inc. | Trade Names
Goodwill [Line Items]
Impairment of infinite lived intangible assets		0.3
Benefit Consultants Group Inc. | Value of customer relationships
Goodwill [Line Items]
Impairment of finite lived intangible assets		2.5
Benefit Consultants Group Inc. | Retirement
Goodwill [Line Items]
Goodwill impairment	$ 2.0
Benefits Consultants Group System Inc.
Goodwill [Line Items]
Intangible assets		5.0
NTA
Goodwill [Line Items]
Intangible assets		160.4
Madison National
Goodwill [Line Items]
Intangible assets		$ 56.5