Deferred Policy Acquisition Costs (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
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	$ 890	$ 565	$ 975	$ 550
Deferred policy acquisition costs and present value of future profits, additions	180	174	358	329
Deferred policy acquisition costs and present value of future profits, periodic amortization	(165)	(174)	(323)	(332)
Deferred policy acquisition costs and present value of future profits, change included in realized gains	1	1	1	0
Deferred policy acquisition costs and present value of future profits, foreign currency translation	1	(1)	1	(1)
Deferred policy acquisition costs and present value of future profits, change in unrealized	(101)	253	(206)	272
Deferred policy acquisition costs and present value of future profits, ending balance	806	818	806	818
Property and Casualty Insurance [Member]
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Deferred policy acquisition costs, beginning balance	214	203	211	204
Deferred policy acquisition costs, additions	127	123	251	242
Deferred policy acquisition costs, periodic amortization	(123)	(117)	(244)	(237)
Deferred policy acquisition costs, foreign currency translation	1	(1)	1	(1)
Deferred policy acquisition costs, ending balance	219	208	219	208
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	898	793	875	787
Deferred policy acquisition costs, additions	52	49	102	83
Deferred policy acquisition costs, periodic amortization	(33)	(46)	(60)	(73)
Deferred policy acquisition costs, change included in realized gains	1	1	1	0
Deferred policy acquisition costs, ending balance	918	797	918	797
Movement in Deferred Sales Inducements [Roll Forward]
Deferred sales inducements, beginning balance	146	165	149	170
Deferred sales inducements, additions	1	2	5	4
Deferred sales inducements, periodic amortization	(6)	(8)	(13)	(15)
Deferred sales inducements, ending balance	141	159	141	159
Movement in Present Value of Future Insurance Profits [Roll Forward]
Present value of future profits, beginning balance	82	95	85	99
Present value of future profits, periodic amortization	(3)	(3)	(6)	(7)
Present value of future profits, ending balance	79	92	79	92
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	(450)	(691)	(345)	(710)
Unrealized investment gains (losses), change in unrealized	(101)	253	(206)	272
Unrealized investment gains (losses), ending balance	(551)	(438)	(551)	(438)
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	676	362	764	346
Deferred policy acquisition costs and present value of future profits, additions	53	51	107	87
Deferred policy acquisition costs and present value of future profits, periodic amortization	(42)	(57)	(79)	(95)
Deferred policy acquisition costs and present value of future profits, change included in realized gains	1	1	1	0
Deferred policy acquisition costs and present value of future profits, change in unrealized	(101)	253	(206)	272
Deferred policy acquisition costs and present value of future profits, ending balance	$ 587	$ 610	$ 587	$ 610