Investments (Schedule Of Details Of The Amount Of Credit Losses Of OTTI Recognized In Net Income (Loss)) (Details) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2017	Dec. 31, 2016	Mar. 31, 2017	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Amortized Cost	$ 542	$ 666
Net Unrealized Gain/(Loss) Position	50	29
Fair Value	592	695
OTTI in Credit Losses	390	430	$ 393	$ 431	$ 413	$ 382
Corporate bonds [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Amortized Cost	22	80
Net Unrealized Gain/(Loss) Position	6	5
Fair Value	28	85
OTTI in Credit Losses	43	77
ABS [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Amortized Cost	199	212
Net Unrealized Gain/(Loss) Position	20	13
Fair Value	219	225
OTTI in Credit Losses	112	112
RMBS [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Amortized Cost	292	332
Net Unrealized Gain/(Loss) Position	18	6
Fair Value	310	338
OTTI in Credit Losses	188	194
CMBS [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Amortized Cost	18	29
Net Unrealized Gain/(Loss) Position	2	1
Fair Value	20	30
OTTI in Credit Losses	39	39
CLOs [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Amortized Cost	11	11
Net Unrealized Gain/(Loss) Position	4	4
Fair Value	15	15
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	$ 3