Unpaid Claims and Claim Expense Short Duration Contracts (Rollforward of Claims and Claim Adjustment Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Liability for Claims and Claims Adjustment Expense Beginning Balance	$ 2,480	$ 2,110
Reinsurance Recoverable for Unpaid Claims and Claims Adjustments, Beginning Balance	(57)	(81)
Liability For Unpaid Claims And Claims Adjustment Expense Net Of Recoverable, Beginning Balance	2,423	2,029
Current Year Claims and Claims Adjustment Expense	1,561	1,778
Prior Year Claims and Claims Adjustment Expense	(111)	(125)
Liability for Unpaid Claims and Claims Adjustment Expense, Incurred Claims	1,450	1,653
Liability for Unpaid Claims and Claims Adjustment Expense, Claims Paid, Current Year	(473)	(440)
Liability for Unpaid Claims and Claims Adjustment Expense, Claims Paid, Prior Years	(804)	(800)
Liability for Unpaid Claims and Claims Adjustment Expense, Claims Paid	(1,277)	(1,240)
Interest On Liability For Policy And Contract Claims	39	34
Liability for Unpaid Claims and Claims Adjustment Expense, Foreign Currency Translation Gain (Loss)	15	53
Liability for Unpaid Claims and Claims Adjustment Expense Other	54	19
Liability For Unpaid Claims And Claims Adjustment Expense Net Of Recoverable, Ending Balance	2,650	2,423
Reinsurance Recoverable for Unpaid Claims and Claims Adjustments, Ending Balance	80	57
Liability for Claims and Claims Adjustment Expense, Ending Balance	$ 2,730	$ 2,480