Deferred Policy Acquisition Costs (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Movement Analysis of Deferred Policy Acquisition Costs and Present Value of Future Profits [Roll Forward]
Deferred policy acquisition costs and present value of future profits, beginning balance	$ 756	$ 890	$ 821	$ 975
Deferred policy acquisition costs and present value of future profits, additions	184	180	352	358
Deferred policy acquisition costs and present value of future profits, periodic amortization	(195)	(165)	(360)	(323)
Deferred policy acquisition costs and present value of future profits, change included in realized gains	2	1	4	1
Deferred policy acquisition costs and present value of future profits, foreign currency translation	(1)	1	0	1
Deferred policy acquisition costs and present value of future profits, change in unrealized	219	(101)	148	(206)
Deferred policy acquisition costs and present value of future profits, ending balance	965	806	965	806
Property and Casualty Insurance [Member]
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Deferred policy acquisition costs, beginning balance	217	214	221	211
Deferred policy acquisition costs, additions	137	127	258	251
Deferred policy acquisition costs, periodic amortization	(130)	(123)	(256)	(244)
Deferred policy acquisition costs, foreign currency translation	(1)	1	0	1
Deferred policy acquisition costs, ending balance	223	219	223	219
Annuity and Run-off Long-term Care and Life [Member]
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Deferred policy acquisition costs, beginning balance	942	898	925	875
Deferred policy acquisition costs, additions	46	52	90	102
Deferred policy acquisition costs, periodic amortization	(55)	(33)	(84)	(60)
Deferred policy acquisition costs, change included in realized gains	1	1	3	1
Deferred policy acquisition costs, ending balance	934	918	934	918
Movement in Deferred Sales Inducements [Roll Forward]
Deferred sales inducements, beginning balance	128	146	132	149
Deferred sales inducements, additions	1	1	4	5
Deferred sales inducements, periodic amortization	(7)	(6)	(14)	(13)
Deferred sales inducements, change included in realized gains	1	0	1	0
Deferred sales inducements, ending balance	123	141	123	141
Movement in Present Value of Future Insurance Profits [Roll Forward]
Present value of future profits, beginning balance	71	82	74	85
Present value of future profits, periodic amortization	(3)	(3)	(6)	(6)
Present value of future profits, ending balance	68	79	68	79
Movement in Unrealized Gains (Losses) Related to Deferred Policy Acquisition Costs and Present Value of Future Profits [Roll Forward]
Unrealized investment gains (losses), beginning balance	(602)	(450)	(531)	(345)
Unrealized investment gains (losses), change in unrealized	219	(101)	148	(206)
Unrealized investment gains (losses), ending balance	(383)	(551)	(383)	(551)
Movement Analysis of Deferred Policy Acquisition Costs and Present Value of Future Profits [Roll Forward]
Deferred policy acquisition costs and present value of future profits, beginning balance	539	676	600	764
Deferred policy acquisition costs and present value of future profits, additions	47	53	94	107
Deferred policy acquisition costs and present value of future profits, periodic amortization	(65)	(42)	(104)	(79)
Deferred policy acquisition costs and present value of future profits, change included in realized gains	2	1	4	1
Deferred policy acquisition costs and present value of future profits, change in unrealized	219	(101)	148	(206)
Deferred policy acquisition costs and present value of future profits, ending balance	$ 742	$ 587	$ 742	$ 587