Investments (Schedule Of Impaired Mortgage Loans) (Details) $ in Millions	Sep. 30, 2016 USD ($) item	Jun. 30, 2016 USD ($)	Dec. 31, 2015 USD ($) item	Sep. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Dec. 31, 2014 USD ($)
Information about impaired mortgage loans on real estate
Number of impaired mortgage loans on real estate | item	3		2
Principal balance of impaired mortgage loans on real estate	$ 13		$ 8
Valuation allowance associated with impaired mortgage loans on real estate	(3)	$ (2)	(2)	$ (2)	$ (3)	$ (3)
Carrying value of impaired mortgage loans on real estate	$ 10		$ 6