Claim and Claim Adjustment Expense Reserves (International - Net prior year claim and allocated claim adjustment expense reserve development) (Details) - International - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Liability for Claims and Claims Adjustment Expense [Line Items]
Commercial	$ (4)	$ 0	$ (4)	$ 0
Specialty	(1)	(1)	(1)	(1)
Other	0	0	0	0
Total pretax (favorable) unfavorable development	$ (5)	$ (1)	$ (5)	$ (1)