Investments (Narrative) (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022	Dec. 31, 2021
Schedule of Investments [Line Items]
Impairment (recoveries) losses on investments		$ 14.8	$ 0.9
Impairments on fixed maturities credit related losses	$ 4.1
Allowance for credit losses	7.2	7.2	7.1	$ 3.2	$ 7.1
Fixed Maturities [Member]
Schedule of Investments [Line Items]
Impairment (recoveries) losses on investments	10.3	14.8	$ 0.9
Fixed Maturities Including Held For Sale [Member]
Schedule of Investments [Line Items]
Allowance for credit losses	2.4	2.4		2.1
Mortgage Loans [Member]
Schedule of Investments [Line Items]
Allowance for credit losses	$ 7.2	$ 7.2		$ 3.2