Investments (Details 3) (USD $) In Millions, unless otherwise specified	Sep. 30, 2014 Holdings	Dec. 31, 2013 Holdings
Indemnity
Fair value
Less than 12 months	$ 160	$ 129
12 months or longer	21	26
Total	181	155
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 months	2	3
12 months or longer	0	0
Total	2	3
No. of holdings	301	38
Indemnity | Investment grade
Fair value
Less than 12 months	97	112
12 months or longer	8	10
Total	105	122
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 months	1	1
12 months or longer	0	0
Total	1	1
No. of holdings	46	32
Indemnity | Non-investment grade
Fair value
Less than 12 months	63	0
12 months or longer	0	0
Total	63	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 months	1	0
12 months or longer	0	0
Total	1	0
No. of holdings	254	0
Indemnity | Fixed maturities
Fair value
Less than 12 months	160	112
12 months or longer	8	10
Total	168	122
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 months	2	1
12 months or longer	0	0
Total	2	1
No. of holdings	300	32
Indemnity | States & political subdivisions
Fair value
Less than 12 months	0	58
12 months or longer	8	0
Total	8	58
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 months	0	1
12 months or longer	0	0
Total	0	1
No. of holdings	3	21
Indemnity | Corporate debt securities
Fair value
Less than 12 months	89	54
12 months or longer	0	10
Total	89	64
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 months	1	0
12 months or longer	0	0
Total	1	0
No. of holdings	262	11
Indemnity | Residential mortgage-backed securities
Fair value
Less than 12 months	7
12 months or longer	0
Total	7
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 months	0
12 months or longer	0
Total	0
No. of holdings	4
Indemnity | Commercial mortgage-backed securities
Fair value
Less than 12 months	42
12 months or longer	0
Total	42
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 months	1
12 months or longer	0
Total	1
No. of holdings	23
Indemnity | Collateralized debt obligations
Fair value
Less than 12 months	17
12 months or longer	0
Total	17
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 months	0
12 months or longer	0
Total	0
No. of holdings	6
Indemnity | Other debt securities
Fair value
Less than 12 months	5
12 months or longer	0
Total	5
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 months	0
12 months or longer	0
Total	0
No. of holdings	2
Indemnity | Nonredeemable preferred stock
Fair value
Less than 12 months		5
12 months or longer		3
Total		8
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 months		1
12 months or longer		0
Total		1
No. of holdings		4
Indemnity | Common stock
Fair value
Less than 12 months	0	12
12 months or longer	13	13
Total	13	25
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 months	0	1
12 months or longer	0	0
Total	0	1
No. of holdings	1	2
Exchange
Fair value
Less than 12 months	1,367	2,050
12 months or longer	472	176
Total	1,839	2,226
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 months	22	74
12 months or longer	11	5
Total	33	79
No. of holdings	794	388
Exchange | Investment grade
Fair value
Less than 12 months	790	1,707
12 months or longer	294	62
Total	1,084	1,769
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 months	8	57
12 months or longer	7	4
Total	15	61
No. of holdings	203	344
Exchange | Non-investment grade
Fair value
Less than 12 months	475	64
12 months or longer	14	0
Total	489	64
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 months	12	4
12 months or longer	2	0
Total	14	4
No. of holdings	569	14
Exchange | Fixed maturities
Fair value
Less than 12 months	1,265	1,771
12 months or longer	308	62
Total	1,573	1,833
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 months	20	61
12 months or longer	9	4
Total	29	65
No. of holdings	772	358
Exchange | U.S. government & agencies
Fair value
Less than 12 months		1
12 months or longer		0
Total		1
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 months		0
12 months or longer		0
Total		0
No. of holdings		2
Exchange | U.S. treasury
Fair value
Less than 12 months	1
12 months or longer	0
Total	1
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 months	0
12 months or longer	0
Total	0
No. of holdings	3
Exchange | States & political subdivisions
Fair value
Less than 12 months	45	408
12 months or longer	64	18
Total	109	426
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 months	0	13
12 months or longer	1	2
Total	1	15
No. of holdings	25	100
Exchange | Foreign government securities
Fair value
Less than 12 months	0	5
12 months or longer	5	0
Total	5	5
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 months	0	0
12 months or longer	0	0
Total	0	0
No. of holdings	1	1
Exchange | Corporate debt securities
Fair value
Less than 12 months	1,190	1,251
12 months or longer	205	36
Total	1,395	1,287
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 months	20	43
12 months or longer	6	2
Total	26	45
No. of holdings	730	237
Exchange | Residential mortgage-backed securities
Fair value
Less than 12 months	15	71
12 months or longer	27	8
Total	42	79
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 months	0	4
12 months or longer	1	0
Total	1	4
No. of holdings	8	12
Exchange | Commercial mortgage-backed securities
Fair value
Less than 12 months	1	5
12 months or longer	0	0
Total	1	5
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 months	0	0
12 months or longer	0	0
Total	0	0
No. of holdings	1	1
Exchange | Other debt securities
Fair value
Less than 12 months	13	30
12 months or longer	7	0
Total	20	30
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 months	0	1
12 months or longer	1	0
Total	1	1
No. of holdings	4	5
Exchange | Nonredeemable preferred stock
Fair value
Less than 12 months	102	182
12 months or longer	33	13
Total	135	195
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 months	2	10
12 months or longer	1	1
Total	3	11
No. of holdings	20	27
Exchange | Common stock
Fair value
Less than 12 months	0	97
12 months or longer	131	101
Total	131	198
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 months	0	3
12 months or longer	1	0
Total	$ 1	$ 3
No. of holdings	2	3