Future Policy Benefit Reserves - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Insurance [Abstract]
Liability for unpaid claims and claims adjustment expense, long term care policies, period increase (decrease)	$ 8	$ 186
Liability for unpaid claims and claims adjustment, cash flows beyond tenor, normative rate grading term	10 years		10 years
Insurance claims and policyholders benefits, including policyholders' dividends, remeasurement impact	$ (41)	(211)	$ (75)	$ (205)
Liability for future policy benefit, expected future gross premium, discounted, before reinsurance	$ 3,711	$ 4,102	$ 3,711	$ 4,102
Liability for future policy benefit, weighted-average duration	12 years	12 years	12 years	12 years
Liability for future policy benefit, adverse development, expense	$ 109	$ 154	$ 152	$ 154
Liability future policy benefit, losses recognized in prior period	$ 26	$ 1	$ 37	$ 1