Investments Investments - Other investments by type (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Investment Holdings [Line Items]
Policy loans	$ 548	$ 561
Other	1,352	1,300
Agent loans
Investment Holdings [Line Items]
Other	654	620
Bank loans
Investment Holdings [Line Items]
Other	370	422
Real estate
Investment Holdings [Line Items]
Other	242	228
Derivatives and other
Investment Holdings [Line Items]
Other	$ 86	$ 30

Amount before allowance of loans made to policy and contract holders using their life insurance contracts' cash value or separate accounts as collateral. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums over and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

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(e))
-URI http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.7(a)(7))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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