Investments (Schedule of Details Of The Amount Of Credit Losses Of OTTI Recognized In Net Income (Loss)) (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Amortized Cost	$ 666	$ 640
Gross Unrealized Losses and OTTI	29	30
Fair Value	695	670
OTTI in Credit Losses	430	382	$ 380	$ 404
Corporate bonds [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Amortized Cost	80	31
Gross Unrealized Losses and OTTI	5	(2)
Fair Value	85	29
OTTI in Credit Losses	77	28
ABS [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Amortized Cost	212	199
Gross Unrealized Losses and OTTI	13	13
Fair Value	225	212
OTTI in Credit Losses	112	108
RMBS [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Amortized Cost	332	365
Gross Unrealized Losses and OTTI	6	12
Fair Value	338	377
OTTI in Credit Losses	194	193
CMBS [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Amortized Cost	29	34
Gross Unrealized Losses and OTTI	1	4
Fair Value	30	38
OTTI in Credit Losses	39	48
CLOs [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Amortized Cost	11	11
Gross Unrealized Losses and OTTI	4	3
Fair Value	15	14
OTTI in Credit Losses	5	$ 5
State and municipal bonds [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Amortized Cost	2
Fair Value	2
OTTI in Credit Losses	$ 3