Policy Claims and Benefits Policy Claims and Benefits (Rollforward of Claims and Claim Adjustment Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Liability for Claims and Claims Adjustment Expense Beginning Balance	$ 7,556	$ 6,786	$ 6,585
Reinsurance Recoverable for Unpaid Claims and Claims Adjustments, Beginning Balance	(641)	(564)	(433)
Liability For Unpaid Claims And Claims Adjustment Expense Net Of Recoverable, Beginning Balance	6,915	6,222	6,152
Current Year Claims and Claims Adjustment Expense	13,181	11,195	10,307
Prior Year Claims and Claims Adjustment Expense	(377)	(123)	(154)
Liability for Unpaid Claims and Claims Adjustment Expense, Incurred Claims	12,804	11,318	10,461
Liability for Unpaid Claims and Claims Adjustment Expense, Claims Paid, Current Year	(6,284)	(5,617)	(5,140)
Liability for Unpaid Claims and Claims Adjustment Expense, Claims Paid, Prior Years	(5,810)	(5,204)	(5,305)
Liability for Unpaid Claims and Claims Adjustment Expense, Claims Paid	(12,094)	(10,821)	(10,445)
Interest On Liability For Policy And Contract Claims	31	36	33
Liability for Unpaid Claims and Claims Adjustment Expense, Foreign Currency Translation Gain (Loss)	(159)	(160)	(21)
Liability for Unpaid Claims and Claims Adjustment Expense Other	(128)	(196)	(54)
Liability For Unpaid Claims And Claims Adjustment Expense Net Of Recoverable, Ending Balance	7,497	6,915	6,222
Reinsurance Recoverable for Unpaid Claims and Claims Adjustments, Ending Balance	556	641	564
Liability for Claims and Claims Adjustment Expense, Ending Balance	$ 8,053	$ 7,556	$ 6,786