Investments (Schedule of Details Of The Amount Of Credit Losses Of OTTI Recognized In Net Income (Loss)) (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2015	Jun. 30, 2016	Sep. 30, 2015	Jun. 30, 2015	Dec. 31, 2014
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Amortized Cost	$ 683	$ 640
Net Unrealized Gain/(Loss) Position	22	30
Fair Value	705	670
OTTI in Credit Losses	436	382	$ 431	$ 378	$ 374	$ 380
Corporate bonds [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Amortized Cost	86	31
Net Unrealized Gain/(Loss) Position	(1)	(2)
Fair Value	85	29
OTTI in Credit Losses	91	28
ABS [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Amortized Cost	218	199
Net Unrealized Gain/(Loss) Position	12	13
Fair Value	230	212
OTTI in Credit Losses	110	108
RMBS [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Amortized Cost	333	365
Net Unrealized Gain/(Loss) Position	7	12
Fair Value	340	377
OTTI in Credit Losses	190	193
CMBS [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Amortized Cost	31	34
Net Unrealized Gain/(Loss) Position	1	4
Fair Value	32	38
OTTI in Credit Losses	39	48
CLOs [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Amortized Cost	11	11
Net Unrealized Gain/(Loss) Position	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	4
Net Unrealized Gain/(Loss) Position	(1)
Fair Value	3
OTTI in Credit Losses	$ 1