Income Tax (Tax Effects of Temporary Differences that Give Rise to Significant Portions of the Deferred Income Tax Asset and Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Deferred Tax Assets, Net [Abstract]
Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals	$ 102	$ 96
Deferred Tax Assets, Operating Loss Carryforwards	846	272
Deferred Tax Assets, Tax Credit Carryforwards	220	108
Deferred Tax Assets, Capital Loss Carryforwards	92	15
Deferred Tax Assets, Investments	1,407	1,092
Deferred Tax Assets, Anticipated Future Foreign Tax Credit	442	267
Deferred Tax Assets, Tax Credit Carryforwards, Foreign	220
Deferred Tax Assets, Gross	3,109	1,850
Deferred Tax Assets, Valuation Allowance	(678)	(567)
Deferred Tax Assets, Net	2,431	1,283
Deferred Tax Liabilities [Abstract]
Deferred Tax Liabilities, Deferred Expense, Deferred Policy Acquisition Cost	931	833
Deferred Tax Liabilities Reinsurance Transactions	3,428	1,789
Deferred Tax Liabilities, Undistributed Foreign Earnings	0	152
Deferred Tax Liabilities, Unrealized Currency Transaction Gains	190	179
Total Deferred Income Tax Liabilities	4,552	3,033
Deferred Tax Liabilities, Net	2,121	1,750
Balance Sheet Presentation Of Deferred Tax Liabilities [Abstract]
Deferred Tax Assets, Other	78	112
Deferred income taxes	2,199	1,862
Deferred Tax Liabilities, Net	2,121	1,750
Deferred Tax Liabilities, Other	$ 3	$ 80