Deferred Policy Acquisition Costs - Progression of deferred policy acquisition costs (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
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		$ 1,203	$ 1,582	$ 1,682	$ 1,216
Deferred policy acquisition costs and present value of future profits, additions		232	247	734	718
Deferred policy acquisition costs and present value of future profits, periodic amortization		(227)	(236)	(622)	(699)
Deferred policy acquisition costs and present value of future profits, annuity unlocking		(77)		(77)	29
Deferred policy acquisition costs and present value of future profits, change included in realized gains		3	3	6	9
Deferred policy acquisition costs and present value of future profits, foreign currency translation		(1)	0	(1)	(1)
Deferred policy acquisition costs and present value of future profits, change in unrealized		(169)	73	(758)	397
Deferred policy acquisition costs and present value of future profits, ending balance		964	1,669	964	1,669
P&C
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Deferred policy acquisition costs, beginning balance		330	298	299	270
Deferred policy acquisition costs, additions		188	181	569	524
Deferred policy acquisition costs, periodic amortization		(194)	(171)	(544)	(485)
Deferred policy acquisition costs, foreign currency translation		(1)	0	(1)	(1)
Deferred policy acquisition costs, ending balance		323	308	323	308
Annuity and Other
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Deferred policy acquisition costs, beginning balance		1,373	1,243	1,285	1,217
Deferred policy acquisition costs, additions		43	65	163	192
Deferred policy acquisition costs, periodic amortization		(29)	(58)	(63)	(193)
Deferred policy acquisition costs, annuity unlocking		(76)		(76)	28
Deferred policy acquisition costs, change included in realized gains		3	3	5	9
Deferred policy acquisition costs, ending balance		1,314	1,253	1,314	1,253
Movement in Deferred Sales Inducements [Roll Forward]
Deferred sales inducements, beginning balance		81	94	86	102
Deferred sales inducements, additions		1	1	2	2
Deferred sales inducements, periodic amortization		(3)	(5)	(10)	(15)
Deferred sales inducements, annuity unlocking		(1)		(1)	1
Deferred sales inducements, change included in realized gains		0	0	1	0
Deferred sales inducements, ending balance		78	90	78	90
Movement in Present Value of Future Insurance Profits [Roll Forward]
Present value of future profits, beginning balance		38	45	42	49
Present value of future profits, periodic amortization		(1)	(2)	(5)	(6)
Present value of future profits, annuity unlocking		0		0	0
Present value of future profits, ending balance		37	43	37	43
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	[1]	(619)	(98)	(30)	(422)
Unrealized investment gains (losses), change in unrealized	[1]	(169)	73	(758)	397
Unrealized investment gains (losses), ending balance	[1]	(788)	(25)	(788)	(25)
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		873	1,284	1,383	946
Deferred policy acquisition costs and present value of future profits, additions		44	66	165	194
Deferred policy acquisition costs and present value of future profits, periodic amortization		(33)	(65)	(78)	(214)
Deferred policy acquisition costs and present value of future profits, annuity unlocking		(77)		(77)	29
Deferred policy acquisition costs and present value of future profits, change included in realized gains		3	3	6	9
Deferred policy acquisition costs and present value of future profits, change in unrealized		(169)	73	(758)	397
Deferred policy acquisition costs and present value of future profits, ending balance		641	1,361	641	1,361
Excluding Unrealized Gains | Annuity and Other
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		1,492	1,382	1,413	1,368
Deferred policy acquisition costs and present value of future profits, change in unrealized		0	0	0	0
Deferred policy acquisition costs and present value of future profits, ending balance		$ 1,429	$ 1,386	$ 1,429	$ 1,386

[1] Adjustments to DPAC related to net unrealized gains/losses on securities and cash flow hedges.