Claim and Claim Adjustment Expense Reserves, Long Term Care Policyholder Reserves (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2020
Long Term Care Policyholder Reserves [Abstract]
Pretax margin included in long term care future policy benefit reserves	$ 72
Premium deficiency in long term care future policy benefit reserves		$ 74	$ 74
Lower Claim Severity [Member]
Long Term Care Policyholder Reserves [Abstract]
Pretax increase (decrease) in claim tax and claim adjustment expense reserves	(40)	(37)
Lower Discount Rate Assumptions and Mortality Assumption Changes [Member]
Long Term Care Policyholder Reserves [Abstract]
Pretax increase (decrease) in claim tax and claim adjustment expense reserves	$ 2	$ 46