Goodwill and Intangible Assets - Schedule of Definite and Indefinite Life Intangible Assets (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Total Definite Life Intangible Assets	$ 280.6	$ 261.0
Total Indefinite Life Intangible Assets	47.8	47.8
Total Intangible Assets	328.4	308.8
Trade Names
Finite-Lived Intangible Assets [Line Items]
Total Indefinite Life Intangible Assets	5.2	5.2
Insurance Licenses
Finite-Lived Intangible Assets [Line Items]
Total Indefinite Life Intangible Assets	42.6	42.6
Value of Business Acquired
Finite-Lived Intangible Assets [Line Items]
Total Definite Life Intangible Assets	24.1	30.2
Customer Relationships
Finite-Lived Intangible Assets [Line Items]
Total Definite Life Intangible Assets	4.3	6.7
Agent Relationships
Finite-Lived Intangible Assets [Line Items]
Total Definite Life Intangible Assets	62.5	68.0
Trade Names
Finite-Lived Intangible Assets [Line Items]
Total Definite Life Intangible Assets	0.0	7.0
Internal-Use Software
Finite-Lived Intangible Assets [Line Items]
Total Definite Life Intangible Assets	$ 189.7	$ 149.1