Future Policy Benefits Reserves - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Insurance [Abstract]
Liability for unpaid claims and claims adjustment expense, long term care policies, period increase (decrease)	$ 15	$ 8
Liability for future policy benefit, expected future gross premium, discounted, before reinsurance	$ 3,792	$ 3,711	$ 3,792	$ 3,711
Liability for future policy benefit, weighted-average duration	11 years	12 years	11 years	12 years
Liability future policy benefit, losses recognized in current period	$ 84	$ 109	$ 128	$ 152
Liability future policy benefit, losses recognized in prior period	$ 20	$ 26	$ 28	$ 37