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, 2013	Dec. 31, 2012
Fixed Maturities [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	$ 8,638	$ 8,222
Gross Unrealized Gains	558	874
Gross Unrealized Losses	75	3
Fair Value	9,121	9,093
Fixed Maturities [Member] | States, Municipalities And Political Subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	3,107	3,040
Gross Unrealized Gains	125	250
Gross Unrealized Losses	21	1
Fair Value	3,211	3,289
Fixed Maturities [Member] | Convertibles And Bonds With Warrants Attached [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	17	31
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	17	31
Fixed Maturities [Member] | United States Government [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	7	7
Gross Unrealized Gains	0	1
Gross Unrealized Losses	0	0
Fair Value	7	8
Fixed Maturities [Member] | Government-Sponsored Enterprises [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	227	164
Gross Unrealized Gains	0	0
Gross Unrealized Losses	27	0
Fair Value	200	164
Fixed Maturities [Member] | Foreign Government [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	10	3
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	10	3
Fixed Maturities [Member] | Commercial Mortgage Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	148	27
Gross Unrealized Gains	0	1
Gross Unrealized Losses	5	0
Fair Value	143	28
Fixed Maturities [Member] | Corporate Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	5,122	4,950
Gross Unrealized Gains	433	622
Gross Unrealized Losses	22	2
Fair Value	5,533	5,570
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	2,523	2,369
Gross Unrealized Gains	1,856	1,014
Gross Unrealized Losses	4	10
Fair Value	4,375	3,373
Equity Securities [Member] | Common Stock [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	2,396	2,270
Gross Unrealized Gains	1,818	977
Gross Unrealized Losses	1	9
Fair Value	4,213	3,238
Equity Securities [Member] | Preferred Stock [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	127	99
Gross Unrealized Gains	38	37
Gross Unrealized Losses	3	1
Fair Value	162	135
Fixed Maturities And Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	11,161	10,591
Gross Unrealized Gains	2,414	1,888
Gross Unrealized Losses	79	13
Fair Value	$ 13,496	$ 12,466