Deferred Policy Acquisition Costs -Deferred policy acquisition costs activity (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Long Duration Contracts [Abstract]
Beginning balance	$ 502	$ 476
Acquisition costs deferred	23	31
Amortization charged to income	(16)	(12)
Experience adjustment	(9)	(14)
Total	500	481
Short-duration contracts	28	20
Property and casualty	4,943	4,342
Balance, end of year	5,471	4,843	$ 5,442
Accident and health insurance
Long Duration Contracts [Abstract]
Beginning balance	322	339
Acquisition costs deferred	13	12
Amortization charged to income	(9)	(7)
Experience adjustment	(9)	(14)
Total	317	330
Traditional life
Long Duration Contracts [Abstract]
Beginning balance	79	47
Acquisition costs deferred	6	11
Amortization charged to income	(3)	(2)
Experience adjustment	0	0
Total	82	56
Interest- sensitive life
Long Duration Contracts [Abstract]
Beginning balance	101	90
Acquisition costs deferred	4	8
Amortization charged to income	(4)	(3)
Experience adjustment	0	0
Total	$ 101	$ 95