Investments (excluding Consolidated Investment Entities) - OTTI (Details) $ in Millions	3 Months Ended
	Mar. 31, 2020 USD ($) security	Mar. 31, 2019 USD ($) security
Available-for-sale Securities, Including Securities Pledged [Line Items]
Impairment	$ 20	$ 26
No. of Securities | security	11	20
Write-downs related to credit impairments	$ 0	$ 26
Intent Impairments	20	0
U.S. corporate public securities
Available-for-sale Securities, Including Securities Pledged [Line Items]
Impairment	$ 19	$ 0
No. of Securities | security	2	0
Foreign corporate private securities
Available-for-sale Securities, Including Securities Pledged [Line Items]
Impairment	$ 0	$ 25
No. of Securities | security	0	3
Residential mortgage-backed
Available-for-sale Securities, Including Securities Pledged [Line Items]
Impairment	$ 1	$ 0
No. of Securities | security	8	15
Commercial mortgage-backed securities
Available-for-sale Securities, Including Securities Pledged [Line Items]
Impairment	$ 0	$ 0
No. of Securities | security	1	0
Other asset-backed securities
Available-for-sale Securities, Including Securities Pledged [Line Items]
Impairment	$ 0	$ 1
No. of Securities | security	0	2