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Debt - Additional Information (Detail) - USD ($) |  |  | 12 Months Ended |
--- | --- | --- | --- | ---
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

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- Definition Line of credit facility covenant compliance debt to capitalization percentage. + References No definition available. + Details
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- Definition Line of credit facility covenant terms maximum debt to capitalization percentage. + References No definition available. + Details
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- Definition Line of credit facility extended borrowing capacity. + References No definition available. + Details
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- Definition Outstanding letters of credit under various bilateral committed letter of credit facilities. + References No definition available. + Details
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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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- 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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- Definition Contractual interest rate for funds borrowed, under the debt agreement. + 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 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + 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 + Details
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- 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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- 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 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 + 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 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 + Details
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- 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 Reference 3: 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(22)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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- 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
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- 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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