Insurance Liabilities (Future Policy Benefits - SOP) (Details) - ULSG - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Dec. 31, 2024	Dec. 31, 2023
Additional Liability, Long-Duration Insurance [Line Items]
Additional Liability, Long-Duration Insurance, before Reinsurance, after Discount Rate Change	$ 9,959	$ 8,966	$ 8,986	$ 7,607
Additional Liability, Long-Duration Insurance, Original Discount Rate, before Cash Flow and Reinsurance	10,168	9,124	9,277	7,784
Additional Liability, Long-Duration Insurance, Cumulative Increase (Decrease) from Cash Flow Change			480	895
Additional Liability, Long-Duration Insurance, Cumulative Increase (Decrease) of Actual Variance from Expected Experience			94	102
Additional Liability, Long-Duration Insurance, Original Discount Rate, before Reinsurance, after Cash Flow Change			$ 9,851	$ 8,781
Additional Liability, Long-Duration Insurance, Interest Income (Expense)	346	295
Additional Liability, Long-Duration Insurance, Net Premium Collected	355	328
Additional Liability, Long-Duration Insurance, Benefit Payment	(384)	(280)
AOCI, Liability for Future Policy Benefit, before Tax	(209)	(158)
Additional Liability, Long-Duration Insurance, Reinsurance Recoverable, after Allowance	1,786	1,521
Additional Liability, Long-Duration Insurance, after Reinsurance	$ 8,173	$ 7,445
Additional Liability, Long-Duration Insurance, Weighted-Average Duration	6 years 7 months 6 days	6 years 7 months 6 days
Additional Liability, Long-Duration Insurance, Weighted-Average Interest Accretion Rate	4.94%	4.94%
Additional Liability, Long-Duration Insurance, Gross Premium Income	$ 801	$ 812