Investments (Investment Income Realized Investment Gains And Losses And Change In Unrealized Investment Gains And Losses) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Investment income:
Interest	$ 428	$ 417	$ 413
Dividends	150	138	122
Other	3	2	3
Total	581	557	538
Less investment expenses	9	8	9
Total	572	549	529
Realized investment gains and losses:
Other	1	3	6
Total	70	133	83
Change in unrealized investment gains and losses:
Unrealized (losses) and gains on investments available-for-sale	(405)	250	299
OCI, portion attributable to Parent	(218)	130	202
OCI, portion attributable to Parent	(618)	370	577
Fixed Maturities
Realized investment gains and losses:
Gross realized gains	18	21	15
Gross realized losses	0	(3)	0
Other-than-temporary impairments	(18)	(15)	(2)
Change in unrealized investment gains and losses:
Unrealized (losses) and gains on investments available-for-sale	(263)	106	(387)
Equity Securities
Realized investment gains and losses:
Gross realized gains	129	136	64
Gross realized losses	(26)	0	0
Other-than-temporary impairments	(34)	(9)	0
Change in unrealized investment gains and losses:
Unrealized (losses) and gains on investments available-for-sale	(362)	278	847
Accumulated Net Unrealized Investment Gain (Loss)
Change in unrealized investment gains and losses:
OCI, portion attributable to Parent	(220)	134	161
OCI, portion attributable to Parent	$ (405)	$ 250	$ 299