Deferred Policy Acquisition Costs (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 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	$ 821	$ 975
Deferred policy acquisition costs and present value of future profits, additions	168	178
Deferred policy acquisition costs and present value of future profits, periodic amortization	(165)	(158)
Deferred policy acquisition costs and present value of future profits, change included in realized gains	2
Deferred policy acquisition costs and present value of future profits, foreign currency translation	1
Deferred policy acquisition costs and present value of future profits, change in unrealized	(71)	(105)
Deferred policy acquisition costs and present value of future profits, ending balance	756	890
Property and Casualty Insurance [Member]
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Deferred policy acquisition costs, beginning balance	221	211
Deferred policy acquisition costs, additions	121	124
Deferred policy acquisition costs, periodic amortization	(126)	(121)
Deferred policy acquisition costs, foreign currency translation	1
Deferred policy acquisition costs, ending balance	217	214
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	925	875
Deferred policy acquisition costs, additions	44	50
Deferred policy acquisition costs, periodic amortization	(29)	(27)
Deferred policy acquisition costs, change included in realized gains	2
Deferred policy acquisition costs, ending balance	942	898
Movement in Deferred Sales Inducements [Roll Forward]
Deferred sales inducements, beginning balance	132	149
Deferred sales inducements, additions	3	4
Deferred sales inducements, periodic amortization	(7)	(7)
Deferred sales inducements, change included in realized gains	0
Deferred sales inducements, ending balance	128	146
Movement in Present Value of Future Insurance Profits [Roll Forward]
Present value of future profits, beginning balance	74	85
Present value of future profits, periodic amortization	(3)	(3)
Present value of future profits, ending balance	71	82
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	(531)	(345)
Unrealized investment gains (losses), change in unrealized	(71)	(105)
Unrealized investment gains (losses), ending balance	(602)	(450)
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	600	764
Deferred policy acquisition costs and present value of future profits, additions	47	54
Deferred policy acquisition costs and present value of future profits, periodic amortization	(39)	(37)
Deferred policy acquisition costs and present value of future profits, change included in realized gains	2
Deferred policy acquisition costs and present value of future profits, change in unrealized	(71)	(105)
Deferred policy acquisition costs and present value of future profits, ending balance	$ 539	$ 676