Insurance (Future Policy Benefits - SOP) (Details) - ULSG - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022	Dec. 31, 2021
Additional Liability, Long-Duration Insurance [Line Items]
Additional Liability, Long-Duration Insurance, before Reinsurance, after Discount Rate Change	$ 7,240	$ 6,971	$ 6,935	$ 7,168
Additional Liability, Long-Duration Insurance, Original Discount Rate, before Cash Flow and Reinsurance	7,587	7,054	7,175	6,731
Additional Liability, Long-Duration Insurance, Cumulative Increase (Decrease) from Cash Flow Change			52	(37)
Additional Liability, Long-Duration Insurance, Cumulative Increase (Decrease) of Actual Variance from Expected Experience			75	157
Additional Liability, Long-Duration Insurance, Original Discount Rate, before Reinsurance, after Cash Flow Change			$ 7,302	$ 6,851
Additional Liability, Long-Duration Insurance, Interest Income (Expense)	265	248
Additional Liability, Long-Duration Insurance, Net Premium Collected	309	324
Additional Liability, Long-Duration Insurance, Benefit Payment	(289)	(369)
Additional Liability, Long-Duration Insurance, Remeasurement Gain (Loss)	0	0
AOCI, Liability for Future Policy Benefit, before Tax	(347)	(83)
Additional Liability, Long-Duration Insurance, Reinsurance Recoverable, after Allowance	1,409	1,393
Additional Liability, Long-Duration Insurance, after Reinsurance	$ 5,831	$ 5,578
Additional Liability, Long-Duration Insurance, Weighted-Average Duration	6 years 8 months 12 days	6 years 8 months 12 days
Additional Liability, Long-Duration Insurance, Weighted-Average Interest Accretion Rate	4.92%	4.90%
Additional Liability, Long-Duration Insurance, Gross Premium Income	$ 798	$ 834