Investments (Schedule Of Details Of The Amount Of Credit Losses Of OTTI Recognized In Net Income (Loss)) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Amortized Cost	$ 484	$ 666
Net Unrealized Gain/(Loss) Position	63	29
Fair Value	547	695
OTTI in Credit Losses	378	430	$ 382	$ 380
Corporate Bonds [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Amortized Cost	17	80
Net Unrealized Gain/(Loss) Position	7	5
Fair Value	24	85
OTTI in Credit Losses	31	77
ABS [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Amortized Cost	182	212
Net Unrealized Gain/(Loss) Position	27	13
Fair Value	209	225
OTTI in Credit Losses	109	112
RMBS [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Amortized Cost	260	332
Net Unrealized Gain/(Loss) Position	22	6
Fair Value	282	338
OTTI in Credit Losses	189	194
CMBS [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Amortized Cost	14	29
Net Unrealized Gain/(Loss) Position	2	1
Fair Value	16	30
OTTI in Credit Losses	41	39
CLOs [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Amortized Cost	11	11
Net Unrealized Gain/(Loss) Position	5	4
Fair Value	16	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