Investments (Narrative) (Details) - USD ($)	9 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Investments [Line Items]
Debt Securities, Held-to-Maturity, Amortized Cost, after Allowance for Credit Loss, Transfer, Amount	$ 8,200,000,000
Debt Securities, Available-for-Sale and Held-to-Maturity, Fair Value	7,800,000,000
Debt Securities, Held-to-Maturity, Transfer, Unrealized Gain (Loss)	428,000,000
Restricted assets in fixed maturities and short-term investments	17,505,000,000	$ 15,721,000,000
Restricted assets in cash	192,000,000	$ 115,000,000
Investments
Investments [Line Items]
Deferred Tax Assets, Valuation Allowance	$ 1,108,000,000