Long-term and Short-term Debt (Committed Facilities) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Debt Instrument [Line Items]
Collateral financing arrangements	$ 4,196us-gaap_SecuredDebt	$ 4,196us-gaap_SecuredDebt
Committed Credit Facility Total [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	12,231
Letters of Credit Issued	6,566
Collateral financing arrangements	2,797
Unused Commitments	2,868
Committed Credit Facility Two [Member]
Debt Instrument [Line Items]
Borrowers	MetLife, Inc. and Missouri Reinsurance, Inc.
Expiration	Jun. 30, 2016
Line of Credit Facility, Maximum Borrowing Capacity	490
Letters of Credit Issued	490
Collateral financing arrangements	0
Unused Commitments	0
Committed Credit Facility Three [Member]
Debt Instrument [Line Items]
Borrowers	MetLife Reinsurance Company of Vermont and MetLife, Inc.
Expiration	Dec. 28, 2024
Line of Credit Facility, Maximum Borrowing Capacity	575
Letters of Credit Issued	350
Collateral financing arrangements	0
Unused Commitments	225
Committed Credit Facility Four [Member]
Debt Instrument [Line Items]
Borrowers	MetLife, Inc.
Expiration	Jun. 20, 2018
Line of Credit Facility, Maximum Borrowing Capacity	520
Letters of Credit Issued	470
Collateral financing arrangements	0
Unused Commitments	50
Committed Credit Facility Five [Member]
Debt Instrument [Line Items]
Borrowers	MetLife Reinsurance Company of South Carolina and MetLife, Inc.
Expiration	Jun. 30, 2037
Line of Credit Facility, Maximum Borrowing Capacity	3,500
Letters of Credit Issued	0
Collateral financing arrangements	2,797
Unused Commitments	703
Committed Credit Facility Six [Member]
Debt Instrument [Line Items]
Borrowers	MetLife Reinsurance Company of Vermont and MetLife, Inc.
Expiration	Dec. 31, 2037
Line of Credit Facility, Maximum Borrowing Capacity	2,896
Letters of Credit Issued	2,049
Collateral financing arrangements	0
Unused Commitments	847
Committed Credit Facility Seven [Member]
Debt Instrument [Line Items]
Borrowers	MetLife Reinsurance Company of Vermont and MetLife, Inc.
Expiration	Sep. 20, 2038
Line of Credit Facility, Maximum Borrowing Capacity	4,250
Letters of Credit Issued	3,207
Collateral financing arrangements	0
Unused Commitments	$ 1,043

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The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

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- Definition

Identification of each affiliate who is permitted to utilize the line of credit (for example, a subsidiary of the reporting entity) and description of its relationship to the reporting entity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 850

-SubTopic 10

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

+ Details

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- Definition

Date the credit facility terminates, in CCYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.19(b),22(b))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

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- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

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- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

+ Details

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- Definition

Carrying value as of the balance sheet date, including the current and noncurrent portions, of collateralized debt obligations (with maturities initially due after one year or beyond the operating cycle, if longer). Such obligations include mortgage loans, chattel loans, and any other borrowings secured by assets of the borrower.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.16)

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 16

-Article 9

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 20, 22

-Article 5

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.16)

-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

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