Investments Investments (Allowance for Credit Loss Roll Forward) (Details) - Available-for-sale Securities [Member] - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Credit Losses on Debt Securities Held, Beginning Balance	$ 95	$ 79	$ 75	$ 37
Financing Receivable, Allowance for Credit Loss, Purchased with Credit Deterioration, Increase	(2)	(2)	(32)	(45)
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Reductions, Securities Sold	(1)	(7)	(9)	(10)
Other-than-Temporary Impairment, Credit Losses Recognized in Earnings, Period Increase (Decrease)	14	1	12	3
Other Than Temporary Impairment Credit Losses Recognized In Earnings Write Offs	(1)	0	(1)	0
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Credit Losses on Debt Securities Held, Ending Balance	111	75	111	75
Corporate Debt Securities [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Credit Losses on Debt Securities Held, Beginning Balance	79	69	62	27
Financing Receivable, Allowance for Credit Loss, Purchased with Credit Deterioration, Increase	(2)	(1)	(32)	(44)
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Reductions, Securities Sold	(1)	(7)	(9)	(10)
Other-than-Temporary Impairment, Credit Losses Recognized in Earnings, Period Increase (Decrease)	14	1	9	1
Other Than Temporary Impairment Credit Losses Recognized In Earnings Write Offs	(1)	0	(1)	0
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Credit Losses on Debt Securities Held, Ending Balance	95	62	95	62
Asset-backed Securities [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Credit Losses on Debt Securities Held, Beginning Balance	15	10	12	10
Financing Receivable, Allowance for Credit Loss, Purchased with Credit Deterioration, Increase	0	0	0	0
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Reductions, Securities Sold	0	0	0	0
Other-than-Temporary Impairment, Credit Losses Recognized in Earnings, Period Increase (Decrease)	0	2	3	2
Other Than Temporary Impairment Credit Losses Recognized In Earnings Write Offs	0	0	0	0
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Credit Losses on Debt Securities Held, Ending Balance	15	12	15	12
Commercial Mortgage Backed Securities [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Credit Losses on Debt Securities Held, Beginning Balance	1	0	1	0
Financing Receivable, Allowance for Credit Loss, Purchased with Credit Deterioration, Increase	0	(1)	0	(1)
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Reductions, Securities Sold	0	0	0	0
Other-than-Temporary Impairment, Credit Losses Recognized in Earnings, Period Increase (Decrease)	0	0	0	0
Other Than Temporary Impairment Credit Losses Recognized In Earnings Write Offs	0	0	0	0
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Credit Losses on Debt Securities Held, Ending Balance	$ 1	$ 1	$ 1	$ 1