Investments (Variable Interest Entities) (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Carrying Amount Assets	$ 14,764	$ 14,591
Carrying Amount Liability	15,613	15,978
Debt Securities
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Carrying Amount Assets	13,056	12,848
Carrying Amount Liability	12,740	12,848
Limited Partner
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Carrying Amount Assets	1,708	1,743
Carrying Amount Liability	$ 2,873	$ 3,130

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

+ Details

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- Definition

Carrying amount of the assets in the reporting entity's statement of financial position that relate to the reporting entity's variable interest in the Variable Interest Entity (VIE), where the reporting entity is not the VIE's primary beneficiary.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph a
-URI http://asc.fasb.org/extlink&oid=108788376&loc=d3e5728-111685

+ Details

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- Definition

Carrying amount of the liabilities in the reporting entity's statement of financial position that relate to the reporting entity's variable interest in the Variable Interest Entity (VIE), where the reporting entity is not the VIE's primary beneficiary.

+ References

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- Details

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