Deferred Policy Acquisition Costs -Deferred policy acquisition costs activity (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Long Duration Contracts [Abstract]
Beginning balance	$ 502	$ 476
Acquisition costs deferred	45	58
Amortization charged to income	(30)	(23)
Experience adjustment	(14)	(23)
Total	503	488
Short-duration contracts	27	23
Property and casualty	5,077	4,538
Ending balance	5,607	5,049	$ 5,442
Accident and health insurance
Long Duration Contracts [Abstract]
Beginning balance	322	339
Acquisition costs deferred	25	20
Amortization charged to income	(16)	(11)
Experience adjustment	(13)	(21)
Total	318	327
Traditional life
Long Duration Contracts [Abstract]
Beginning balance	79	47
Acquisition costs deferred	13	22
Amortization charged to income	(7)	(5)
Experience adjustment	0	(1)
Total	85	63
Interest- sensitive life
Long Duration Contracts [Abstract]
Beginning balance	101	90
Acquisition costs deferred	7	16
Amortization charged to income	(7)	(7)
Experience adjustment	(1)	(1)
Total	$ 100	$ 98