Investments (Changes In The Valuation Allowance Of Impaired Mortgage Loans On Real Estate (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Allowance for Losses
Balance as of beginning-of-year		$ 3	$ 2
Additions			1
Charge-offs, net of recoveries		$ (3)
Balance as of end-of-year	$ 2		$ 3