Investments - Other investments by type (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Schedule of Investments [Line Items]
Other, net	$ 3,767	$ 4,005
Bank loans, net
Schedule of Investments [Line Items]
Other, net	1,117	1,204
Real estate
Schedule of Investments [Line Items]
Other, net	970	1,005
Policy loans
Schedule of Investments [Line Items]
Other, net	882	894
Agent loans, net
Schedule of Investments [Line Items]
Other, net	671	666
Derivatives and other
Schedule of Investments [Line Items]
Other, net	$ 127	$ 236