Claim, Claim Adjustment Expense and Future Policy Benefit Reserves, Life and Group Policyholder Reserves (Details) - USD ($) $ in Millions	3 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Long Term Care Policyholder Reserves [Abstract]
Premium deficiency in long term future policy benefit reserves	$ 74	$ 216
Lower Discount Rate Assumptions and Mortality Assumption Changes [Member]
Long Term Care Policyholder Reserves [Abstract]
Pretax reductions in claim tax and claim adjustment expense reserves	46
Lower Claim Severity [Member]
Long Term Care Policyholder Reserves [Abstract]
Pretax reductions in claim tax and claim adjustment expense reserves	$ (37)	$ (56)	$ (31)