Interest rate under multicurrency facility.

No definition available.

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- Definition

Line of credit facility covenant compliance debt to capitalization percentage.

+ References

No definition available.

+ Details

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Period Type:	instant

- Definition

Line of credit facility covenant terms maximum debt to capitalization percentage.

+ References

No definition available.

+ Details

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Period Type:	instant

- Definition

Line of credit facility extended borrowing capacity.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Outstanding letters of credit under various bilateral committed letter of credit facilities.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
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- Definition

Carrying value as of the balance sheet date of short-term borrowings using unsecured obligations issued by banks, corporations and other borrowers to investors. The maturities of these money market securities generally do not exceed 270 days.

+ 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)(a)(3))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: 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(a)(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: 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(13)(2))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The reference rate for the variable rate of the debt instrument, such as LIBOR or the US Treasury rate and the maturity of the reference rate used, such as three months or six months LIBOR.

+ References

No definition available.

+ Details

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

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

+ References

+ Details

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Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Period remaining on line of credit facility before it terminates, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- 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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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- 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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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: 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(a)(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 2: 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

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

+ References

No definition available.

+ Details

Name:	us-gaap_LongTermDebtFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The cash outflow to repay long-term debt that is not secured by collateral. Excludes repayments of tax exempt unsecured debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3291-108585

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

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- Details

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- Details

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Balance Type:
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- Details

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Data Type:	na
Balance Type:
Period Type:

- Details

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- Details

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Debt - Additional Information (Detail) - USD ($)			12 Months Ended
Debt - Additional Information (Detail) - USD ($)	Nov. 29, 2017	Jun. 27, 2017	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Interest rate under multi currency facility			LIBOR, NIBOR or CDOR plus 1.125%
Capitalization ratio, Maximum			60.00%
Capitalization ratio, Actual			16.10%
Funds available under revolving credit facility			$ 3,000,000,000
Outstanding letters of credit under various bilateral letter of credit facilities			658,000,000
Fair value of Unsecured Senior Notes			2,346,000,000	$ 2,669,000,000
Carrying value of Unsecured Senior Notes			$ 2,712,000,000	$ 3,214,000,000
Senior Notes, Interest at 1.35% Payable Semiannually, Principal Due on December 1, 2017 [Member]
Debt Instrument [Line Items]
Repayment of debt	$ 500,000,000
Senior notes interest rate	1.35%		1.35%	1.35%
Canadian Dollar Offered Rate (CDOR) [Member]
Debt Instrument [Line Items]
Variable rate		1.125%
Five-year Credit Facility [Member]
Debt Instrument [Line Items]
Credit facility, borrowing capacity		$ 3,000,000,000	$ 3,000,000,000
Credit facility, Period		5 years
Credit facility, maturity date			Jun. 27, 2022
Credit facility, extendable borrowing capacity		$ 4,000,000,000
Variable rate basis			LIBOR, NIBOR or CDOR plus
Borrowings under commercial paper			$ 0
Unsecured Credit Facility [Member]
Debt Instrument [Line Items]
Credit facility, Period			5 years
Previous Five Year Credit Facility [Member]
Debt Instrument [Line Items]
Credit facility, borrowing capacity		$ 4,500,000,000
Unsecured Senior Notes [Member]
Debt Instrument [Line Items]
Carrying value of Unsecured Senior Notes			$ 2,480,000,000	$ 2,977,000,000