Investments (Concentrations of Credit Risk - Narrative) (Details) - Foreign government - USD ($) $ in Billions	Sep. 30, 2022	Dec. 31, 2021
Japan
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Government and agency fixed maturity securities	$ 22.9	$ 32.7
Republic of Korea
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Government and agency fixed maturity securities	5.0	$ 7.1
MEXICO
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Government and agency fixed maturity securities	$ 3.1