Employee Benefit Arrangements - Net Actuarial (Gains) Losses (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net (gain) loss recognition	$ 4	$ (50)	$ (14)
Discount Rate
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net (gain) loss recognition	(292)	160	(196)
Asset Returns
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net (gain) loss recognition	263	(207)	142
Mortality Table Assumptions
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net (gain) loss recognition	22	6	14
Demographic Data and other
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net (gain) loss recognition	$ 11	$ (9)	$ 25