Deferred Policy Acquisition Costs (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 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	$ 975	$ 550	$ 901
Deferred policy acquisition costs and present value of future profits, additions	703	701	665
Deferred policy acquisition costs and present value of future profits, periodic amortization	(652)	(644)	(618)
Deferred policy acquisition costs and present value of future profits, annuity unlocking	(20)	2	(37)
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	3	2	(1)
Deferred policy acquisition costs and present value of future profits, foreign currency translation	(2)	(1)
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	(186)	365	(173)
Deferred policy acquisition costs and present value of future profits, ending balance	821	975	550
Property and Casualty Insurance [Member]
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Deferred policy acquisition costs, beginning balance	211	204	189
Deferred policy acquisition costs, additions	497	468	438
Deferred policy acquisition costs, periodic amortization	(485)	(460)	(423)
Deferred policy acquisition costs, foreign currency translation	(2)	(1)
Deferred policy acquisition costs, ending balance	221	211	204
Annuity and Other [Member]
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Deferred policy acquisition costs, beginning balance	875	787	916
Deferred policy acquisition costs, additions	198	222	212
Deferred policy acquisition costs, periodic amortization	(130)	(140)	(148)
Deferred policy acquisition costs, annuity unlocking	(20)	4	(33)
Deferred policy acquisition costs, loss recognition charge			(67)
Deferred policy acquisition costs, change included in realized gains	2	2	(1)
Deferred policy acquisition costs, sale of subsidiaries			(92)
Deferred policy acquisition costs, ending balance	925	875	787
Movement in Deferred Sales Inducements [Roll Forward]
Deferred sales inducements, beginning balance	149	170	189
Deferred sales inducements, additions	8	11	15
Deferred sales inducements, periodic amortization	(26)	(30)	(30)
Deferred sales inducements, annuity unlocking	0	(2)	(4)
Deferred sales inducements, change included in realized gains	1	0	0
Deferred sales inducements, ending balance	132	149	170
Movement in Present Value of Future Insurance Profits [Roll Forward]
Present value of future profits, beginning balance	85	99	144
Present value of future profits, periodic amortization	(11)	(14)	(17)
Present value of future profits, annuity unlocking			0
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	74	85	99
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	(345)	(710)	(537)
Unrealized investment gains (losses), change in unrealized	(186)	365	(173)
Unrealized investment gains (losses), ending balance	(531)	(345)	(710)
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	764	346	712
Deferred policy acquisition costs and present value of future profits, additions	206	233	227
Deferred policy acquisition costs and present value of future profits, periodic amortization	(167)	(184)	(195)
Deferred policy acquisition costs and present value of future profits, annuity unlocking	(20)	2	(37)
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	3	2	(1)
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	(186)	365	(173)
Deferred policy acquisition costs and present value of future profits, ending balance	$ 600	$ 764	$ 346