Investments (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Schedule of Investments [Line Items]
Impairment (recoveries) losses on investments	$ 15.7	$ (0.1)	$ 16.3	$ 0.1
Fixed Maturities [Member]
Schedule of Investments [Line Items]
Impairment (recoveries) losses on investments	15.7		16.3
Fixed Maturities Including Held For Sale [Member]
Schedule of Investments [Line Items]
Allowance for credit losses	3.1		3.1		$ 0.3
Mortgage Loans [Member]
Schedule of Investments [Line Items]
Allowance for credit losses	$ 5.2		$ 5.2		$ 7.1