Change in additional paid in capital as a result of a capital contribution, including transfers of ownership.

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Estimated fair value of invested assets transferred from affiliates.

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Estimated fair value of assets transfered to affiliates.

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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.

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Cash includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the customer may deposit additional funds at any time and effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid Investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Short-term investments, exclusive of cash equivalents, generally consist of marketable securities intended to be sold within one year (or the normal operating cycle if longer) and may include trading securities, available-for-sale securities, or held-to-maturity securities (if maturing within one year), as applicable.

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Face (par) amount of debt instrument at time of issuance.

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Contractual interest rate for funds borrowed, under the debt agreement.

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Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

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This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized.

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The increase (decrease) during the reporting period in the amount owed to the reporting entity in the form of loans and obligations (generally evidenced by promissory notes) made to the following types of related parties: a parent company and its subsidiaries; subsidiaries of a common parent; an entity and trust for the benefit of employees, such as pension and profit-sharing trusts that are managed by or under the trusteeship of the entity's management, an entity and its principal owners, management, or member of their immediate families, affiliates, or other parties with the ability to exert significant influence.

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The cash inflow associated with the sale of equity method investments, which are investments in joint ventures and entities in which the entity has an equity ownership interest normally of 20 to 50 percent and exercises significant influence.

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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.

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Amount of selling, general and administrative expenses resulting from transactions, excluding transactions that are eliminated in consolidated or combined financial statements, with related party.

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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.

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Investments (Related Party Investment Transactions - Narrative) (Details) - USD ($)		3 Months Ended	12 Months Ended
	Apr. 28, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Nov. 01, 2016	Apr. 01, 2016
Related Party Transaction [Line Items]
Increase (Decrease) in Notes Receivable, Related Parties	$ 1,100,000,000
Equity Method Investments		$ 89,000,000	$ 2,300,000,000
Proceeds from Sale of Equity Method Investments		286,000,000
Adjustments to Additional Paid in Capital, Capital Contribution		$ 202,000,000
Related party investment administrative services			$ 1,100,000,000	$ 1,000,000,000	$ 847,000,000
Other investments
Related Party Transaction [Line Items]
Debt instrument, face amount					1,100,000,000
Other investments \| Related Party Loan One
Related Party Transaction [Line Items]
Debt Instrument, interest rate			4.21%
Debt Instrument, Maturity Date			Sep. 30, 2032
Other investments \| Related Party Loan Two
Related Party Transaction [Line Items]
Debt Instrument, interest rate			5.10%
Debt Instrument, Maturity Date			Dec. 31, 2033
Metlife Investment Advisors, LLC [Member]
Related Party Transaction [Line Items]
Related party investment administrative services			$ 49,000,000	93,000,000	98,000,000
Affiliated Entity
Related Party Transaction [Line Items]
Assets Transferred To Affiliates, Estimated Fair Value			0	292,000,000	1,500,000,000
Transfers of Financial Assets Accounted for as Sale, Amortized Cost of Assets Obtained as Proceeds			0	294,000,000	1,400,000,000
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale, Gain (Loss) on Sale			0	(2,000,000)	27,000,000
Assets Transferred From Affiliates, Estimated Fair Value			0	$ 0	$ 5,600,000,000
Affiliated Entity \| Debt Securities [Member]
Related Party Transaction [Line Items]
Assets Transferred From Affiliates, Estimated Fair Value			$ 370,000,000
Affiliated Entity \| Recapture MLUS [Member]
Related Party Transaction [Line Items]
Cash, Cash Equivalents, and Short-term Investments							$ 4,300,000,000
Contract Termination [Member] \| Affiliated Entity \| Recapture MLUS [Member]
Related Party Transaction [Line Items]
Cash, Cash Equivalents, and Short-term Investments						$ 5,200,000,000	$ 5,200,000,000