Investments (Related Party Investment Transactions) (Details) - Affiliated Entity [Member] - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Invested Assets Transferred To and From Affiliates
Estimated fair value of invested assets transferred to former affiliates	$ 292	$ 1,495	$ 185
Amortized cost of invested assets transferred to former affiliates	294	1,400	169
Net investment gains (losses) recognized on transfers	(2)	27	16
Change Additional Paid In Capital Recognized On Transfers	0	68	0
Estimated fair value of invested assets transferred from former affiliates	$ 0	$ 5,582	$ 928

Estimated fair value of invested assets transferred from affiliates.

No definition available.

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- Definition

Estimated fair value of assets transfered to affiliates.

+ References

No definition available.

+ Details

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- Definition

Reflect the change of additional paid in capital on equity type investments such as real estate and real estate joint ventures.

+ References

No definition available.

+ Details

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- Definition

Represents the amortized cost of assets received on transfer of financial assets in a securitization, asset-backed financing arrangement, or a similar transfer which transaction is recognized as a sale of the transferred financial assets.

+ References

No definition available.

+ Details

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- Definition

Reflects, by transferred financial asset type, the amount of sales proceeds in excess of or deficient from the sum of the carrying amounts of transferred financial assets plus transaction costs, including those transactions in which the seller/transferor has continuing involvement with the financial assets that have been transferred.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=82924980&loc=d3e107207-111719

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 10
-Section 40
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=65892426&loc=d3e96813-111708

+ Details

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- Definition

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.

+ References

No definition available.

+ Details

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