Investments (Investment in Leverage Leases) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Investment in leveraged leases
Rental receivables, net	$ 1,414	$ 1,491
Estimated residual values	1,148	1,325
Subtotal	2,562met_InvestmentInLeveragedLeases	2,816met_InvestmentInLeveragedLeases
Unearned income	(777)	(870)
Investment in leases, net of non-recourse debt	1,785	1,946
Rental receivables, net	1,750	1,806
Estimated residual values	145	90
Subtotal	1,895met_InvestmentInDirectFinancingLeases	1,896met_InvestmentInDirectFinancingLeases
Unearned income	(776)	(796)
Investment in leases, net of non-recourse debt	$ 1,119	$ 1,100

This element represents the subtotal of rental receivables, net plus estimated residual value of the leased assets.

No definition available.

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- Definition

This element represents the subtotal of rental receivables, net plus estimated residual value of the leased assets.

+ References

No definition available.

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- Definition

The net investment in direct financing leases as of the balance sheet date consisting of: (a) minimum lease payments due on direct financing leases, (b) unguaranteed residual value, and (c) any unamortized initial direct costs; less: (i) executory costs, (ii) unearned income, and (iii) the accumulated allowance for uncollectible minimum lease payments.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

-SubTopic 30

-Section 50

-Paragraph 4

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- Definition

The remaining (unamortized) difference between the gross investment in a direct financing lease and the cost or carrying amount, if different, of the leased property as of the balance sheet date.

+ References

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- Definition

Amount of remaining payments as of the balance sheet date that lessees are obligated to make or can be required to make under direct financing leases, including any guarantee of residual value and executory costs. The amount also includes any guaranteed rental payments by an unrelated third-party provided that are financially capable of making such payments.

+ References

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-Publisher FASB

-Name Accounting Standards Codification

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- Definition

The estimate of the lease property's economic value at the end of the direct financing lease term excluding any amounts guaranteed by either the lessee or a third-party.

+ References

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-Publisher FASB

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- Definition

The estimated portion of pretax income and investment tax credit remaining to be allocated to income over the lease term.

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- Definition

The net investment in arrangements meeting the criteria for classification as leveraged leases including deferred taxes.

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- Definition

This element represents leveraged lease rentals receivable, net of that portion of the rental applicable to principal and interest on the nonrecourse debt.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

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- Definition

The estimate of the value of the leased asset at the end of the lease term.

+ References

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