Deferred Policy Acquisition Costs (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
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	$ 550	$ 901
Deferred policy acquisition costs and present value of future profits, additions	155	167
Deferred policy acquisition costs and present value of future profits, periodic amortization	(158)	(150)
Deferred policy acquisition costs and present value of future profits, change included in realized gains	(1)
Deferred policy acquisition costs and present value of future profits, change in unrealized	19	(2)
Deferred policy acquisition costs and present value of future profits, ending balance	565	916
Property and Casualty Insurance [Member]
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Deferred policy acquisition costs, beginning balance	204	189
Deferred policy acquisition costs, additions	119	103
Deferred policy acquisition costs, periodic amortization	(120)	(101)
Deferred policy acquisition costs, ending balance	203	191
Annuity and Other [Member]
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Deferred policy acquisition costs, beginning balance	787	916
Deferred policy acquisition costs, additions	34	59
Deferred policy acquisition costs, periodic amortization	(27)	(36)
Deferred policy acquisition costs, change included in realized gains	(1)
Deferred policy acquisition costs, ending balance	793	939
Movement in Deferred Sales Inducements [Roll Forward]
Deferred sales inducements, beginning balance	170	189
Deferred sales inducements, additions	2	5
Deferred sales inducements, periodic amortization	(7)	(8)
Deferred sales inducements, ending balance	165	186
Movement in Present Value of Future Insurance Profits [Roll Forward]
Present value of future profits, beginning balance	99	144
Present value of future profits, periodic amortization	(4)	(5)
Present value of future profits, ending balance	95	139
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	(710)	(537)
Unrealized investment gains (losses), change in unrealized	19	(2)
Unrealized investment gains (losses), ending balance	(691)	(539)
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	346	712
Deferred policy acquisition costs and present value of future profits, additions	36	64
Deferred policy acquisition costs and present value of future profits, periodic amortization	(38)	(49)
Deferred policy acquisition costs and present value of future profits, change included in realized gains	(1)
Deferred policy acquisition costs and present value of future profits, change in unrealized	19	(2)
Deferred policy acquisition costs and present value of future profits, ending balance	$ 362	$ 725