Claim and Claim Adjustment Expense Reserves (Life & Group Policyholder Reserves) (Details) - USD ($) $ in Millions	3 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Liability for Claims and Claims Adjustment Expense [Abstract]
Liability for unpaid claims and claims adjustment expense, structured settlement obligations, period increase (decrease)	$ 46
Liability for unpaid claims and claims adjustment expense, long term care policies, period increase (decrease)	(37)
Liability for unpaid claims and claims adjustment expense, period increase (decrease)		$ (56)
Premium deficiency and future policy benefit	$ 74	$ 216