Acquisitions and Dispositions (Details Textuals 2) (USD $) In Billions, except Share data, unless otherwise specified	12 Months Ended
Dec. 31, 2010	Nov. 01, 2010
Acquisitions and Dispositions [Abstract]
Business Acquisition, Effective Date of Acquisition	Nov. 01, 2010
Business Acquisition, Name of Acquired Entity	American Life Insurance Company ("American Life") and Delaware American Life Insurance Company ("DelAm"), (American Life, together with DelAm, collectively, "ALICO")
Total purchase price for acquisition		$ 16.4
Business Acquisition Reason	The ALICO Acquisition significantly broadened the Company’s diversification by product, distribution and geography, meaningfully accelerated MetLife’s global growth strategy, and provides the opportunity to build an international franchise leveraging the key strengths of ALICO.
Cash consideration paid for business acquisition		7.2
Equity Units Stated Interest Percentage	5.00%
Stock Purchase Contracts, Average Stated Interest Rate	3.02%
Debt Instrument, Interest Rate, Average Stated	1.98%
Business Acquisition [Line Items]
Equity Units, Shares Transferred	40,000,000
Total value of shares transferred to the seller	3.0
American Life Insurance Company ("American Life") and Delaware American Life Insurance ("DelAm") [Member]
Acquisitions and Dispositions [Abstract]
Business Acquisition, Effective Date of Acquisition	Nov. 01, 2010
American Life Insurance Company ("American Life") and Delaware American Life Insurance ("DelAm") [Member] \| Common Stock [Member]
Business Acquisition [Line Items]
Equity Units, Shares Transferred	78,239,712
American Life Insurance Company ("American Life") and Delaware American Life Insurance ("DelAm") [Member] \| Convertible Preferred Stock [Member]
Business Acquisition [Line Items]
Equity Units, Shares Transferred	6,857,000
American Life Insurance Company ("American Life") and Delaware American Life Insurance ("DelAm") [Member] \| Equity Units [Member]
Business Acquisition [Line Items]
Total value of shares transferred to the seller	$ 3.0

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The total cost of the acquired entity including the cash paid to shareholders of acquired entities, fair value of debt and equity securities issued to shareholders of acquired entities, the fair value of the liabilities assumed, and direct costs of the acquisition.

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Date when the acquirer obtains control of the acquiree, in CCYY-MM-DD format.

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Value of equity interests (such as common shares, preferred shares, or partnership interest) issued or issuable to acquire the entity.

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Name of the acquired entity.

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This element represents a description of the primary reason for the business combination which may consist of general categories such as top-line growth, synergistic benefits, market share, and diversification and the more detailed factors that might apply.

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