Leasing Activities - Cross-Border Energy Lease Investments (Detail) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Leases [Abstract]
Scheduled lease payments to PHI, net of non-recourse debt	$ 223	$ 1,852
Less: Unearned and deferred income	(56)	(615)
Investment in finance leases held in trust	167	1,237
Less: Deferred income tax liabilities	(83)	(756)
Net investment in finance leases held in trust	$ 84	$ 481

Leveraged leases net investment in leveraged leases minimum payments to be received.

No definition available.

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- Definition

The amount of cash, securities, or other assets held by a third-party trustee pursuant to the terms of an agreement which assets are available to be used by beneficiaries to that agreement only within the specific terms thereof and which agreement is expected to terminate more than one year from the balance sheet date (or operating cycle, if longer) at which time the assets held-in-trust will be released or forfeited.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(b))

-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

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- Details

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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.

+ 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 (d)

-URI http://asc.fasb.org/extlink&oid=7662307&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 45

-Paragraph 5

-URI http://asc.fasb.org/extlink&oid=7662751&loc=d3e45152-112736

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=7662473&loc=d3e43930-112732

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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 35

-Paragraph 33

-URI http://asc.fasb.org/extlink&oid=7662473&loc=d3e43930-112732

Reference 2: 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=7662307&loc=d3e42840-112730

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