Claim and Claim Adjustment Expense Reserves and Future Policy Benefit Reserves (International - Net prior year claim and allocated claim adjustment expense reserve development) (Details) - International - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Liability for Claims and Claims Adjustment Expense [Line Items]
Commercial	$ (10)	$ (35)	$ (2)
Specialty	(4)	36	3
Other	1	1	(3)
Total pretax (favorable) unfavorable development	$ (13)	$ 2	$ (2)