Investments (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Schedule of Investments [Line Items]
Accrued investment income receivable	$ 256		$ 245
Fair value of collateral received at time of securities lending transactions	$ 2,252		$ 2,457
Securities lending transactions ratio of fair value of collateral held to fair value of securities loaned	102.00%		102.00%
Debt Securities, Available-for-Sale, Allowance for Credit Loss	$ (8)		$ (9)
United States Government Securities [Member]
Schedule of Investments [Line Items]
Debt Securities, Available-for-Sale, Allowance for Credit Loss	0		0
Residential Mortgage-Backed Securities [Member]
Schedule of Investments [Line Items]
Debt Securities, Available-for-Sale, Allowance for Credit Loss	0		0
Fixed Maturities [Member]
Schedule of Investments [Line Items]
Proceeds from Sale of Available-for-sale Securities	5,410	$ 3,646
Overnight and Continuous [Member] | Cash [Member]
Schedule of Investments [Line Items]
Collateral received for securities loaned, at carrying value	2,127		2,221
Overnight and Continuous [Member] | United States Government Securities [Member]
Schedule of Investments [Line Items]
Collateral received for securities loaned, at carrying value	104		224
Overnight and Continuous [Member] | Residential Mortgage-Backed Securities [Member]
Schedule of Investments [Line Items]
Collateral received for securities loaned, at carrying value	$ 21		$ 12