Employee Benefit Arrangements - Obligations and Funded Status (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Change in plan assets:
Fair value of plan assets, ending balance	$ 1,964
Accumulated other comprehensive (income) loss, net of tax	(7)	$ (7)	$ (15)
Other Postretirement Benefits
Change in benefit obligation:
Benefits obligations, beginning balance	16
Benefits obligations, ending balance	18	16
Pension Plan
Change in benefit obligation:
Benefits obligations, beginning balance	2,140	2,294
Service cost	24	25	24
Interest cost	92	86	93
Net actuarial (gains) losses	259	(157)
Benefits paid	(106)	(108)
(Gain) loss recognized due to curtailment	1	0
Benefits obligations, ending balance	2,410	2,140	2,294
Change in plan assets:
Fair value of plan assets, beginning balance	1,605	1,764
Actual return on plan assets	376	(78)
Employer contributions	85	27
Benefits paid	(106)	(108)
Fair value of plan assets, ending balance	1,960	1,605	$ 1,764
Funded status at end of the year	(450)	(535)
Accrued benefit cost	(450)	(535)
Net amount recognized	(450)	(535)
Prior service cost (credit)	0	(1)
Tax effect	0	0
Accumulated other comprehensive (income) loss, net of tax	$ 0	$ (1)