Finance Assets, net (Summary of Net Investments in Finance Leases) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Receivables [Abstract]
Rents receivable, net	$ 696	$ 805
Unguaranteed residual value	427	495
Unearned income	(201)	(240)
Investments in finance leases	922	1,060
Deferred income taxes	(407)	(717)
Net investments in finance leases	$ 515	$ 343

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

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 30
-Section 30
-Paragraph 14
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=77895730&loc=d3e42840-112730

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- Definition

Taxes arising from arrangements meeting the criteria for classification as leveraged leases due to timing differences between accounting and tax income recognition.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 30
-Section 35
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=77915205&loc=d3e43930-112732

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 30
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=77907235&loc=d3e45152-112736

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- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 30
-Section 30
-Paragraph 14
-URI http://asc.fasb.org/extlink&oid=77895730&loc=d3e42840-112730

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 30
-Section 35
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=77915205&loc=d3e43930-112732

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- Definition

The gross rentals receivable equal to the future cash flows from the lessee.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 30
-Section 25
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=77899714&loc=d3e42229-112728

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 30
-Section 30
-Paragraph 14
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=77895730&loc=d3e42840-112730

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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
-Topic 840
-SubTopic 30
-Section 30
-Paragraph 14
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=77895730&loc=d3e42840-112730

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- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 30
-Section 30
-Paragraph 14
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=77895730&loc=d3e42840-112730

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No definition available.

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