Deferred Policy Acquisition Costs (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Long Duration Contracts [Abstract]
Beginning balance	$ 5,940
Total	5,946	$ 5,471
Ending balance	5,946	5,471
Accident and health insurance
Long Duration Contracts [Abstract]
Beginning balance	511	502
Acquisition costs deferred	43	23
Amortization charged to income	(28)	(16)
Experience adjustment	(11)	(9)
Total	515	500
Short-duration contracts	31	28
Ending balance	515	500
Accident and health insurance
Long Duration Contracts [Abstract]
Beginning balance	321	322
Acquisition costs deferred	26	13
Amortization charged to income	(20)	(9)
Experience adjustment	(10)	(9)
Total	317	317
Ending balance	317	317
Traditional life
Long Duration Contracts [Abstract]
Beginning balance	90	79
Acquisition costs deferred	13	6
Amortization charged to income	(5)	(3)
Experience adjustment	(1)	0
Total	97	82
Ending balance	97	82
Interest-sensitive life insurance
Long Duration Contracts [Abstract]
Beginning balance	100	101
Acquisition costs deferred	4	4
Amortization charged to income	(3)	(4)
Experience adjustment	0	0
Total	101	101
Ending balance	101	101
Property and casualty
Long Duration Contracts [Abstract]
Property and casualty	$ 5,400	$ 4,943