Condensed Financial Information (Parent Company) (Support Agreements - Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Condensed Financial Statements, Captions [Line Items]
Derivative Assets, Fair Value, Net	$ 9,068	$ 8,626
Unsecured derivative liability positions guaranteed by MetLife, Inc.	3,871	4,290
Derivative Liability, Fair Value, Amount Offset Against Collateral	69	57
Parent Company \| Support Agreement Exeter Obligations [Member]
Condensed Financial Statements, Captions [Line Items]
Amount guaranteed under support agreement	$ 1,000
Parent Company \| Support Agreement MetLife Reinsurance Company of Vermont [Member]
Condensed Financial Statements, Captions [Line Items]
Guaranteed adjusted capital levels	equal to or greater than 200% of authorized control level risk-based capital
Parent Company \| Support Agreement MetLife Reinsurance Company of Charleston [Member]
Condensed Financial Statements, Captions [Line Items]
Guaranteed adjusted capital levels	equal to or greater than 200% of the company action level risk-based capital
Parent Company \| Support Agreement - Guarantees of Subsidiary Derivative Obligations [Member]
Condensed Financial Statements, Captions [Line Items]
Derivative Assets, Fair Value, Net	$ 302	515
Unsecured derivative liability positions guaranteed by MetLife, Inc.	84	126
Estimated fair value of collateral provided to counterparties by the subsidiaries	84	114
Derivative Liability, Fair Value, Amount Offset Against Collateral	$ 0	$ 12

The amount of obligations supported under the issued support agreement.

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Disclosure of the guaranteed minimum level of regulatory based total adjusted capital level for entity in domestic jurisdiction.

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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.

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- Definition

Amount of right to receive securities collateral under master netting arrangements that have not been offset against derivative liabilities.

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Fair value, after offset of derivative liability, of financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, before offset against an obligation to return collateral under a master netting arrangement. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement.

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Fair value, after offset of derivative asset, of financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, elected not to be and before offset against a right to receive collateral under a master netting arrangement. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

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