Deferred Policy Acquisition Costs (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 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	$ 965	$ 806	$ 821	$ 975
Deferred policy acquisition costs and present value of future profits, additions	215	172	567	530
Deferred policy acquisition costs and present value of future profits, periodic amortization	(177)	(175)	(537)	(498)
Deferred policy acquisition costs and present value of future profits, change included in realized gains	3	2	7	3
Deferred policy acquisition costs and present value of future profits, foreign currency translation	(2)	(2)	(2)	(1)
Deferred policy acquisition costs and present value of future profits, change in unrealized	(11)	55	137	(151)
Deferred policy acquisition costs and present value of future profits, ending balance	993	858	993	858
Property and Casualty Insurance [Member]
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Deferred policy acquisition costs, beginning balance	223	219	221	211
Deferred policy acquisition costs, additions	138	129	396	380
Deferred policy acquisition costs, periodic amortization	(132)	(127)	(388)	(371)
Deferred policy acquisition costs, foreign currency translation	(2)	(2)	(2)	(1)
Deferred policy acquisition costs, ending balance	227	219	227	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	934	918	925	875
Deferred policy acquisition costs, additions	74	42	164	144
Deferred policy acquisition costs, periodic amortization	(36)	(38)	(120)	(98)
Deferred policy acquisition costs, change included in realized gains	3	1	6	2
Deferred policy acquisition costs, ending balance	975	923	975	923
Movement in Deferred Sales Inducements [Roll Forward]
Deferred sales inducements, beginning balance	123	141	132	149
Deferred sales inducements, additions	3	1	7	6
Deferred sales inducements, periodic amortization	(6)	(7)	(20)	(20)
Deferred sales inducements, change included in realized gains	0	1	1	1
Deferred sales inducements, ending balance	120	136	120	136
Movement in Present Value of Future Insurance Profits [Roll Forward]
Present value of future profits, beginning balance	68	79	74	85
Present value of future profits, periodic amortization	(3)	(3)	(9)	(9)
Present value of future profits, ending balance	65	76	65	76
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	(383)	(551)	(531)	(345)
Unrealized investment gains (losses), change in unrealized	(11)	55	137	(151)
Unrealized investment gains (losses), ending balance	(394)	(496)	(394)	(496)
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	742	587	600	764
Deferred policy acquisition costs and present value of future profits, additions	77	43	171	150
Deferred policy acquisition costs and present value of future profits, periodic amortization	(45)	(48)	(149)	(127)
Deferred policy acquisition costs and present value of future profits, change included in realized gains	3	2	7	3
Deferred policy acquisition costs and present value of future profits, change in unrealized	(11)	55	137	(151)
Deferred policy acquisition costs and present value of future profits, ending balance	$ 766	$ 639	$ 766	$ 639