Investments - Other investments by type (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Investment [Line Items]
Other, net	$ 3,689	$ 4,005
Bank loans
Investment [Line Items]
Other, net	1,018	1,204
Real estate
Investment [Line Items]
Other, net	974	1,005
Policy loans
Investment [Line Items]
Other, net	754	894
Agent loans
Investment [Line Items]
Other, net	631	666
Derivatives and other
Investment [Line Items]
Other, net	$ 312	$ 236

Amount of investments classified as other.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.1(f,g))
-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.12)
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Name:	us-gaap_OtherInvestments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant