Deferred Policy Acquisition Costs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 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	$ 821	$ 975	$ 550
Deferred policy acquisition costs and present value of future profits, additions	754	703	701
Deferred policy acquisition costs and present value of future profits, periodic amortization	(710)	(652)	(644)
Deferred policy acquisition costs and present value of future profits, annuity unlocking	35	(20)	2
Deferred policy acquisition costs and present value of future profits, change included in realized gains	9	3	2
Deferred policy acquisition costs and present value of future profits, sale of subsidiaries	(19)
Deferred policy acquisition costs and present value of future profits, foreign currency translation	(3)	(2)	(1)
Deferred policy acquisition costs and present value of future profits, change in unrealized	297	(186)	365
Deferred policy acquisition costs and present value of future profits, ending balance	1,184	821	975
Property and Casualty Insurance [Member]
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Deferred policy acquisition costs, beginning balance	221	211	204
Deferred policy acquisition costs, additions	519	497	468
Deferred policy acquisition costs, periodic amortization	(511)	(485)	(460)
Deferred policy acquisition costs, foreign currency translation	(3)	(2)	(1)
Deferred policy acquisition costs, ending balance	226	221	211
Annuity and Other [Member]
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Deferred policy acquisition costs, beginning balance	925	875	787
Deferred policy acquisition costs, additions	224	198	222
Deferred policy acquisition costs, periodic amortization	(162)	(130)	(140)
Deferred policy acquisition costs, annuity unlocking	31	(20)	4
Deferred policy acquisition costs, change included in realized gains	8	2	2
Deferred policy acquisition costs, sale of subsidiaries	(8)
Deferred policy acquisition costs, ending balance	1,018	925	875
Movement in Deferred Sales Inducements [Roll Forward]
Deferred sales inducements, beginning balance	132	149	170
Deferred sales inducements, additions	11	8	11
Deferred sales inducements, periodic amortization	(26)	(26)	(30)
Deferred sales inducements, annuity unlocking	4	0	(2)
Deferred sales inducements, change included in realized gains	1	1	0
Deferred sales inducements, sale of subsidiaries	(3)
Deferred sales inducements, ending balance	119	132	149
Movement in Present Value of Future Insurance Profits [Roll Forward]
Present value of future profits, beginning balance	74	85	99
Present value of future profits, periodic amortization	(11)	(11)	(14)
Present value of future profits, annuity unlocking			0
Present value of future profits, sale of subsidiaries	(8)
Present value of future profits, ending balance	55	74	85
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)	(710)
Unrealized investment gains (losses), change in unrealized	297	(186)	365
Unrealized investment gains (losses), ending balance	(234)	(531)	(345)
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	346
Deferred policy acquisition costs and present value of future profits, additions	235	206	233
Deferred policy acquisition costs and present value of future profits, periodic amortization	(199)	(167)	(184)
Deferred policy acquisition costs and present value of future profits, annuity unlocking	35	(20)	2
Deferred policy acquisition costs and present value of future profits, change included in realized gains	9	3	2
Deferred policy acquisition costs and present value of future profits, sale of subsidiaries	(19)
Deferred policy acquisition costs and present value of future profits, change in unrealized	297	(186)	365
Deferred policy acquisition costs and present value of future profits, ending balance	958	600	764
Excluding Unrealized Gains [Member] | Annuity and Other [Member]
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	1,131	1,109	1,056
Deferred policy acquisition costs and present value of future profits, change in unrealized	0	0	0
Deferred policy acquisition costs and present value of future profits, ending balance	$ 1,192	$ 1,131	$ 1,109