Deferred Policy Acquisition Costs - Progression of deferred policy acquisition costs (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
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	$ 818	$ 1,203	$ 1,037	$ 1,682
Deferred policy acquisition costs and present value of future profits, additions	175	232	561	734
Deferred policy acquisition costs and present value of future profits, periodic amortization	(212)	(227)	(597)	(622)
Deferred policy acquisition costs and present value of future profits, annuity unlocking	(114)	(77)	(114)	(77)
Deferred policy acquisition costs and present value of future profits, change included in realized gains	(2)	3	7	6
Deferred policy acquisition costs and present value of future profits, foreign currency translation	1	(1)	(1)	(1)
Deferred policy acquisition costs and present value of future profits, change in unrealized	(169)	(169)	(396)	(758)
Deferred policy acquisition costs and present value of future profits, ending balance	497	964	497	964
P&C
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Deferred policy acquisition costs, beginning balance	296	330	322	299
Deferred policy acquisition costs, additions	142	188	448	569
Deferred policy acquisition costs, periodic amortization	(170)	(194)	(500)	(544)
Deferred policy acquisition costs, foreign currency translation	1	(1)	(1)	(1)
Deferred policy acquisition costs, ending balance	269	323	269	323
Annuity and Other
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Deferred policy acquisition costs, beginning balance	1,342	1,373	1,303	1,285
Deferred policy acquisition costs, additions	33	43	112	163
Deferred policy acquisition costs, periodic amortization	(39)	(29)	(87)	(63)
Deferred policy acquisition cost, annuity unlocking	(118)	(76)	(118)	(76)
Deferred policy acquisition costs, change included in realized gains	(2)	3	6	5
Deferred policy acquisition costs, ending balance	1,216	1,314	1,216	1,314
Movement in Deferred Sales Inducements [Roll Forward]
Deferred sales inducements, beginning balance	73	81	75	86
Deferred sales inducements, additions	0	1	1	2
Deferred sales inducements, periodic amortization	(2)	(3)	(6)	(10)
Deferred sales inducements, annuity unlocking	4	(1)	4	(1)
Deferred sales inducements, change included in realized gains	0	0	1	1
Deferred sales inducements, ending balance	75	78	75	78
Movement in Present Value of Future Insurance Profits [Roll Forward]
Present value of future profits, beginning balance	33	38	36	42
Present value of future profits, periodic amortization	(1)	(1)	(4)	(5)
Present value of future insurance profits, annuity unlocking	0	0	0	0
Present value of future profits, ending balance	32	37	32	37
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	(926)	(619)	(699)	(30)
Unrealized investment gains (losses), change in unrealized	(169)	(169)	(396)	(758)
Unrealized investment gains (losses), ending balance	(1,095)	(788)	(1,095)	(788)
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	522	873	715	1,383
Deferred policy acquisition costs and present value of future profits, additions	33	44	113	165
Deferred policy acquisition costs and present value of future profits, periodic amortization	(42)	(33)	(97)	(78)
Deferred policy acquisition costs and present value of future profits, annuity unlocking	(114)	(77)	(114)	(77)
Deferred policy acquisition costs and present value of future profits, change included in realized gains	(2)	3	7	6
Deferred policy acquisition costs and present value of future profits, change in unrealized	(169)	(169)	(396)	(758)
Deferred policy acquisition costs and present value of future profits, ending balance	228	641	228	641
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	1,448	1,492	1,414	1,413
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	$ 1,323	$ 1,429	$ 1,323	$ 1,429