Insurance (Obligations Under Funding Agreements - FHLB Common Stock) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Insurance [Abstract]
Federal Home Loan Bank Stock	$ 64	$ 71
Federal Home Loan Bank, Advances, Branch of FHLB Bank, Amount of Advances	$ 595	$ 595

Federal Home Loan Bank (FHLB) stock represents an equity interest in a FHLB. It does not have a readily determinable fair value because its ownership is restricted and it lacks a market (liquidity).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 325
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=75031641&loc=d3e63345-112809

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