Investments (Evaluation of Fixed Maturity Securities AFS in an Unrealized Loss Position- Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ 28,100
Equal to or Greater than 12 Months Gross Unrealized Loss	26,175	$ 24,394
Below Investment Grade
Debt Securities, Available-for-sale [Line Items]
Equal to or Greater than 12 Months Gross Unrealized Loss	769	$ 719
Fixed maturity securities without an allowance for credit loss
Debt Securities, Available-for-sale [Line Items]
Change in Gross Unrealized Temporary Loss	$ 2,300