Fair Value Measurements (Details 3) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
US Treasury and Government [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Financial assets, Beginning Balance	$ 20	$ 0
Total realized/unrealized gains (losses) included in Net income	(2)	0
Total realized/unrealized gains (losses) included in other comprehensive income (loss)	(3)	0
Purchases and issuances	0	20
Sales and settlements	0	0
Transfer into Level 3	0	0
Transfer out of Level 3	0	0
Financial assets, Ending Balance	15	20
States, municipalities and political subdivisions [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Financial assets, Beginning Balance	58	83	20
Total realized/unrealized gains (losses) included in Net income	(1)	0	0
Total realized/unrealized gains (losses) included in other comprehensive income (loss)	(2)	4	4
Purchases and issuances	10	19	58
Sales and settlements	0	(7)	(4)
Transfer into Level 3	0	8	17
Transfer out of Level 3	(4)	(49)	(12)
Financial assets, Ending Balance	61	58	83
Residential Mortgage Backed Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Financial assets, Beginning Balance	371	361	312
Total realized/unrealized gains (losses) included in Net income	5	5	3
Total realized/unrealized gains (losses) included in other comprehensive income (loss)	24	17	(9)
Purchases and issuances	6	96	42
Sales and settlements	(53)	(45)	(38)
Transfer into Level 3	86	228	127
Transfer out of Level 3	(123)	(291)	(76)
Financial assets, Ending Balance	316	371	361
Commercial Mortgage Backed Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Financial assets, Beginning Balance	22	19	6
Total realized/unrealized gains (losses) included in Net income	(1)	1	1
Total realized/unrealized gains (losses) included in other comprehensive income (loss)	(1)	2	0
Purchases and issuances	0	0	9
Sales and settlements	0	0	0
Transfer into Level 3	8	0	13
Transfer out of Level 3	0	0	(10)
Financial assets, Ending Balance	28	22	19
Asset-backed Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Financial assets, Beginning Balance	253	228	124
Total realized/unrealized gains (losses) included in Net income	4	7	1
Total realized/unrealized gains (losses) included in other comprehensive income (loss)	(3)	8	0
Purchases and issuances	12	55	179
Sales and settlements	(57)	(36)	(29)
Transfer into Level 3	11	14	4
Transfer out of Level 3	(145)	(23)	(51)
Financial assets, Ending Balance	75	253	228
All other corporate [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Financial assets, Beginning Balance	236	291	312
Total realized/unrealized gains (losses) included in Net income	1	3	1
Total realized/unrealized gains (losses) included in other comprehensive income (loss)	(14)	9	15
Purchases and issuances	113	86	57
Sales and settlements	(17)	(35)	(43)
Transfer into Level 3	24	15	86
Transfer out of Level 3	(8)	(133)	(137)
Financial assets, Ending Balance	335	236	291
Trading fixed maturities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Financial assets, Beginning Balance		1	3
Total realized/unrealized gains (losses) included in Net income		0	0
Total realized/unrealized gains (losses) included in other comprehensive income (loss)		0	0
Purchases and issuances		0	0
Sales and settlements		0	0
Transfer into Level 3		0	0
Transfer out of Level 3		(1)	(2)
Financial assets, Ending Balance		0	1
Equity securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Financial assets, Beginning Balance	37	11	21
Total realized/unrealized gains (losses) included in Net income	(1)	0	0
Total realized/unrealized gains (losses) included in other comprehensive income (loss)	6	2	1
Purchases and issuances	53	30	2
Sales and settlements	(12)	0	(2)
Transfer into Level 3	0	13	2
Transfer out of Level 3	(52)	(19)	(13)
Financial assets, Ending Balance	31	37	11
Assets of Managed Investment Entities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Financial assets, Beginning Balance	40	44	48
Total realized/unrealized gains (losses) included in Net income	(5)	0	(8)
Total realized/unrealized gains (losses) included in other comprehensive income (loss)	0	0	0
Purchases and issuances	8	20	32
Sales and settlements	(7)	(14)	(18)
Transfer into Level 3	0	13	9
Transfer out of Level 3	(6)	(23)	(19)
Financial assets, Ending Balance	$ 30	$ 40	$ 44