Investments (Analysis Of Cost Or Amortized Cost Gross Unrealized Gains And Losses And Fair Value For Investments) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Fixed Maturities
Schedule of Available-for-sale Securities
Cost or amortized cost	$ 8,871	$ 8,638
Gross unrealized gains	607	558
Gross unrealized losses	18	75
Fair value	9,460	9,121
Fixed Maturities | Corporate Securities
Schedule of Available-for-sale Securities
Cost or amortized cost	5,117	5,122
Gross unrealized gains	420	433
Gross unrealized losses	11	22
Fair value	5,526	5,533
Fixed Maturities | States, Municipalities and Political Subdivisions
Schedule of Available-for-sale Securities
Cost or amortized cost	3,267	3,107
Gross unrealized gains	178	125
Gross unrealized losses	2	21
Fair value	3,443	3,211
Fixed Maturities | Commercial Mortgage Backed Securities
Schedule of Available-for-sale Securities
Cost or amortized cost	250	148
Gross unrealized gains	9	0
Gross unrealized losses	0	5
Fair value	259	143
Fixed Maturities | Government-Sponsored Enterprises
Schedule of Available-for-sale Securities
Cost or amortized cost	213	227
Gross unrealized gains	0	0
Gross unrealized losses	5	27
Fair value	208	200
Fixed Maturities | Foreign Government
Schedule of Available-for-sale Securities
Cost or amortized cost	10	10
Gross unrealized gains	0	0
Gross unrealized losses	0	0
Fair value	10	10
Fixed Maturities | Convertibles and Bonds with Warrants Attached
Schedule of Available-for-sale Securities
Cost or amortized cost	7	17
Gross unrealized gains	0	0
Gross unrealized losses	0	0
Fair value	7	17
Fixed Maturities | United States Government
Schedule of Available-for-sale Securities
Cost or amortized cost	7	7
Gross unrealized gains	0	0
Gross unrealized losses	0	0
Fair value	7	7
Equity Securities
Schedule of Available-for-sale Securities
Cost or amortized cost	2,728	2,523
Gross unrealized gains	2,134	1,856
Gross unrealized losses	4	4
Fair value	4,858	4,375
Equity Securities | Common Equities
Schedule of Available-for-sale Securities
Cost or amortized cost	2,583	2,396
Gross unrealized gains	2,099	1,818
Gross unrealized losses	3	1
Fair value	4,679	4,213
Equity Securities | Nonredeemable Preferred Equities
Schedule of Available-for-sale Securities
Cost or amortized cost	145	127
Gross unrealized gains	35	38
Gross unrealized losses	1	3
Fair value	179	162
Fixed Maturities And Equity Securities
Schedule of Available-for-sale Securities
Cost or amortized cost	11,599	11,161
Gross unrealized gains	2,741	2,414
Gross unrealized losses	22	79
Fair value	$ 14,318	$ 13,496