Goodwill and Specifically Identifiable Intangible Assets (Schedule Of Intangible Assets By Reportable Segment) (Details) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016
Finite And Indefinife Lived Intangible Assets Net [Abstract]
Gross carrying amount		$ 105	$ 105
Accumulated amortization		47	43
Retirement Plan Services Segment [Member] | Mutual Fund Contract Rights [Member]
Finite And Indefinife Lived Intangible Assets Net [Abstract]
Gross carrying amount	[1]	5	5
Life Insurance Segment [Member] | Sales Force [Member]
Finite And Indefinife Lived Intangible Assets Net [Abstract]
Gross carrying amount		100	100
Accumulated amortization		$ 47	$ 43

[1] No amortization recorded as the intangible asset has indefinite life.