Deferred Policy Acquisition Costs Deferred Policy Acquisition Costs (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
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	$ 901	$ 1,031	$ 1,329
Deferred Policy Acquisition Costs and Present Value of Future Profits, Additions	665	690	625
Deferred Policy Acquisition Costs and Present Value of Future Profits, Periodic amortization	(618)	(616)	(592)
Deferred Policy Acquisition Costs and Present Value of Future Profits, Annuity unlocking	(37)	5	(42)
Deferred Policy Acquisition Costs and Present Value of Future Profits, Loss recognition charge	(79)
Deferred Policy Acquisition Costs and Present Value of Future Profits, Change included in realized gains	(1)	13	9
Deferred Policy Acquisition Costs and Present Value of Future Profits, Sale of subsidiaries	(108)
Deferred Policy Acquisition Costs and Present Value of Future Profits, Change in unrealized	(173)	(222)	(298)
Deferred Policy Acquisition Costs and Present Value of Future Profits, Ending Balance	550	901	1,031
Property and Casualty Insurance [Member]
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Deferred Policy Acquisition Costs, Beginning Balance	189	181	186
Deferred Policy Acquisition Costs, Additions	438	433	399
Deferred Policy Acquisition Cost, Periodic amortization	(423)	(425)	(404)
Deferred Policy Acquisition Costs, Ending Balance	204	189	181
Annuity and Other [Member]
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Deferred Policy Acquisition Costs, Beginning Balance	916	812	781
Deferred Policy Acquisition Costs, Additions	212	239	195
Deferred Policy Acquisition Cost, Periodic amortization	(148)	(146)	(139)
Deferred Policy Acquisition Cost, Annuity unlocking	(33)	(2)	(34)
Deferred Policy Acquisition Cost, Loss recognition charge	(67)
Deferred Policy Acquisition Cost, Change included in realized gains	(1)	13	9
Deferred Policy Acquisition Cost, Sale of subsidiaries	(92)
Deferred Policy Acquisition Costs, Ending Balance	787	916	812
Movement in Deferred Sales Inducements [Roll Forward]
Deferred Sales Inducements, Beginning Balance	189	189	189
Deferred Sales Inducements, Additions	15	18	31
Deferred Sales Inducements, Periodic amortization	(30)	(24)	(22)
Deferred Sales Inducements, Annuity unlocking	(4)	6	(9)
Deferred Sales Inducements, Ending Balance	170	189	189
Movement in Present Value of Future Insurance Profits [Roll Forward]
Present Value of Future Profits, Beginning Balance	144	164	190
Present Value of Future Profits, Periodic amortization	(17)	(21)	(27)
Present Value of Future Profits, Annuity unlocking		1	1
Present Value of Future Profits, Loss recognition charge	(12)
Present Value of Future Profits, Sale of subsidiaries	(16)
Present Value of Future Profits, Ending Balance	99	144	164
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	(537)	(315)	(17)
Unrealized Investment Gains (Losses), Change in unrealized	(173)	(222)	(298)
Unrealized Investment Gains (Losses), Ending Balance	(710)	(537)	(315)
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	712	850	1,143
Deferred Policy Acquisition Costs and Present Value of Future Profits, Additions	227	257	226
Deferred Policy Acquisition Costs and Present Value of Future Profits, Periodic amortization	(195)	(191)	(188)
Deferred Policy Acquisition Costs and Present Value of Future Profits, Annuity unlocking	(37)	5	(42)
Deferred Policy Acquisition Costs and Present Value of Future Profits, Loss recognition charge	(79)
Deferred Policy Acquisition Costs and Present Value of Future Profits, Change included in realized gains	(1)	13	9
Deferred Policy Acquisition Costs and Present Value of Future Profits, Sale of subsidiaries	(108)
Deferred Policy Acquisition Costs and Present Value of Future Profits, Change in unrealized	(173)	(222)	(298)
Deferred Policy Acquisition Costs and Present Value of Future Profits, Ending Balance	$ 346	$ 712	$ 850