Investments (excluding Consolidated Investment Entities) - OTTI (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($) security	Dec. 31, 2018 USD ($) security	Dec. 31, 2017 USD ($) security
Available-for-sale Securities, Including Securities Pledged [Line Items]
Impairment	$ 60	$ 28	$ 20
No. of Securities | security	315	69	53
Write-downs related to credit impairments	$ 28	$ 19	$ 18
Impairment, Intent-related	32	9	2
State, municipalities, and political subdivisions
Available-for-sale Securities, Including Securities Pledged [Line Items]
Impairment	$ 0	$ 0	$ 0
No. of Securities | security	8	0	2
U.S. corporate public securities
Available-for-sale Securities, Including Securities Pledged [Line Items]
Impairment	$ 18	$ 6	$ 1
No. of Securities | security	38	2	3
U.S. corporate private securities
Available-for-sale Securities, Including Securities Pledged [Line Items]
Impairment	$ 1	$ 0	$ 0
No. of Securities | security	18	0	0
Foreign corporate public securities and foreign governments
Available-for-sale Securities, Including Securities Pledged [Line Items]
Impairment	$ 5	$ 2	$ 2
No. of Securities | security	22	3	3
Foreign corporate private securities
Available-for-sale Securities, Including Securities Pledged [Line Items]
Impairment	$ 26	$ 15	$ 15
No. of Securities | security	12	1	2
Residential mortgage-backed securities
Available-for-sale Securities, Including Securities Pledged [Line Items]
Impairment	$ 5	$ 5	$ 1
No. of Securities | security	89	61	40
Other
Available-for-sale Securities, Including Securities Pledged [Line Items]
Impairment	$ 5	$ 0	$ 1
No. of Securities | security	128	2	3