Deferred Policy Acquisition Costs (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
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	$ 1,184	$ 821
Deferred policy acquisition costs and present value of future profits, additions	205	168
Deferred policy acquisition costs and present value of future profits, periodic amortization	(166)	(165)
Deferred policy acquisition costs and present value of future profits, change included in realized gains	2	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	(170)	(71)
Deferred policy acquisition costs and present value of future profits, ending balance	1,055	756
Property and Casualty Insurance [Member]
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Deferred policy acquisition costs, beginning balance	226	221
Deferred policy acquisition costs, additions	132	121
Deferred policy acquisition costs, periodic amortization	(134)	(126)
Deferred policy acquisition costs, foreign currency translation		1
Deferred policy acquisition costs, ending balance	224	217
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	1,018	925
Deferred policy acquisition costs, additions	68	44
Deferred policy acquisition costs, periodic amortization	(25)	(29)
Deferred policy acquisition costs, change included in realized gains	2	2
Deferred policy acquisition costs, ending balance	1,063	942
Movement in Deferred Sales Inducements [Roll Forward]
Deferred sales inducements, beginning balance	119	132
Deferred sales inducements, additions	5	3
Deferred sales inducements, periodic amortization	(5)	(7)
Deferred sales inducements, change included in realized gains	0	0
Deferred sales inducements, ending balance	119	128
Movement in Present Value of Future Insurance Profits [Roll Forward]
Present value of future profits, beginning balance	55	74
Present value of future profits, periodic amortization	(2)	(3)
Present value of future profits, ending balance	53	71
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	(234)	(531)
Unrealized investment gains (losses), change in unrealized	(170)	(71)
Unrealized investment gains (losses), ending balance	(404)	(602)
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	958	600
Deferred policy acquisition costs and present value of future profits, additions	73	47
Deferred policy acquisition costs and present value of future profits, periodic amortization	(32)	(39)
Deferred policy acquisition costs and present value of future profits, change included in realized gains	2	2
Deferred policy acquisition costs and present value of future profits, change in unrealized	(170)	(71)
Deferred policy acquisition costs and present value of future profits, ending balance	831	539
Excluding Unrealized Gains [Member] | Annuity and Run-off Long-term Care and Life [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	1,192	1,131
Deferred policy acquisition costs and present value of future profits, change in unrealized	0	0
Deferred policy acquisition costs and present value of future profits, ending balance	$ 1,235	$ 1,141