| **Derivative Financial Instruments and Risk Management (Tables)**                                                       | 9 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
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| **Derivative Instruments and Hedging Activities Disclosure [Abstract]**                                                 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| Location and fair value of derivative instruments reported in the Consolidated Statements of Financial Position         | The location and fair value of derivative instruments reported in the Consolidated Statements of Financial Position were as follows:(Millions of dollars)        Asset (Liability) Fair Value Consolidated Statements ofFinancial Position Location September 30, 2016 December 31, 2015Designated derivatives     Interest rate contractsOther assets $5 $51Interest rate contractsAccrued expenses (2) (4)Cross currency contractsOther assets 4 1Cross currency contractsAccrued expenses (15) —   $(8) $48Undesignated derivatives     Foreign exchange contractsOther assets $2 $3Foreign exchange contractsAccrued expenses (5) (6)Cross currency contractsOther assets 28 36   $25 $33                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| Schedule of effect of derivatives designated as fair value hedging instruments in the Consolidated Statements of Profit | The effect of derivatives designated as hedging instruments on the Consolidated Statements of Profit was as follows:Fair Value Hedges(Millions of dollars)  Three Months EndedSeptember 30, 2016 Three Months EndedSeptember 30, 2015 Classification Gains(Losses)onDerivatives Gains(Losses)onBorrowings  Gains(Losses)onDerivatives Gains (Losses)onBorrowingsInterest rate contractsOther income (expense) $(11) $11 $3 $(3)             Nine Months EndedSeptember 30, 2016 Nine Months EndedSeptember 30, 2015 Classification Gains(Losses)onDerivatives Gains(Losses)onBorrowings  Gains(Losses)onDerivatives Gains (Losses)onBorrowingsInterest rate contractsOther income (expense) $(11) $10 $(11) $10                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| Schedule of effect of derivatives designated as cash flow hedging instruments in the Consolidated Statements of Profit  | Cash Flow Hedges(Millions of dollars)Three Months Ended September 30, 2016  Recognized in Earnings Amounts of Gains (Losses) Recognized in AOCI (Effective Portion)Classification Reclassified from AOCI to Earnings(Effective Portion) Recognized in Earnings (Ineffective Portion)Interest rate contracts$2Interest expense $— $—Cross currency contracts(17)Other income (expense) (10) — $(15)  $(10) $—        Three Months Ended September 30, 2015  Recognized in Earnings Amounts of Gains (Losses) Recognized in AOCI (Effective Portion)Classification Reclassified from AOCI to Earnings(Effective Portion) Recognized in Earnings (Ineffective Portion)Interest rate contracts$(1)Interest expense $(1) $—        Nine Months Ended September 30, 2016  Recognized in Earnings Amounts of Gains (Losses) Recognized in AOCI (Effective Portion)Classification Reclassified from AOCI to Earnings(Effective Portion) Recognized in Earnings (Ineffective Portion)Interest rate contracts$—Interest expense $(3) $—Cross currency contracts(23)Other income (expense) (16) — $(23)  $(19) $—        Nine Months Ended September 30, 2015  Recognized in Earnings Amounts of Gains (Losses) Recognized in AOCI (Effective Portion)Classification Reclassified from AOCI to Earnings(Effective Portion) Recognized in Earnings (Ineffective Portion)Interest rate contracts$1Interest expense $(4) $—        |
| Schedule of effect of derivatives not designated as hedging instruments on the Consolidated Statements of Profit        | The effect of derivatives not designated as hedging instruments on the Consolidated Statements of Profit was as follows:(Millions of dollars)  Three Months Ended September 30, Classification 2016 2015Foreign exchange contractsOther income (expense) $(5) $(2)Cross currency contractsOther income (expense) — 8   $(5) $6         Nine Months Ended September 30, Classification 2016 2015Foreign exchange contractsOther income (expense) $(21) $(34)Cross currency contractsOther income (expense) (12) 16   $(33) $(18)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| Schedule of offsetting of derivative assets and liabilities                                                             | The effect of net settlement provisions of the master netting agreements on our derivative balances upon an event of default or a termination event was as follows: Offsetting of Derivative Assets and Liabilities    (Millions of dollars)      September 30, 2016 December 31, 2015Derivative Assets    Gross Amount of Recognized Assets $39 $91Gross Amounts Offset — —Net Amount of Assets(1) 39 91Gross Amounts Not Offset (3) (5)Net Amount $36 $86     Derivative Liabilities    Gross Amount of Recognized Liabilities $(22) $(10)Gross Amounts Offset — —Net Amount of Liabilities(1) (22) (10)Gross Amounts Not Offset 3 5Net Amount $(19) $(5)     (1) As presented in the Consolidated Statements of Financial Position.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |

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| - Definition
Tabular disclosure of derivative and other financial assets and liabilities that are subject to offsetting, including master netting arrangements.
+ References
No definition available.
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No definition available.
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|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Tabular disclosure for cash flow hedging instruments of (a) the location and amount of gains and losses reported in the statement of financial performance and (b) the location and fair value amounts of the instruments reported in the statement of financial position.
+ References
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| - Definition
Tabular disclosure of the location and amount of derivative instruments and nonderivative instruments designated as hedging instruments reported before netting adjustments, and the amount of gain (loss) on derivative instruments and nonderivative instruments designated and qualified as hedging instruments.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5624171-113959Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4A -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5618551-113959
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|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Tabular disclosure of the location and fair value amounts of derivative instruments (and nonderivative instruments that are designated and qualify as hedging instruments) reported in the statement of financial position.
+ References
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| - Definition
Tabular disclosure for other derivative instruments not designated as hedging instruments of (a) the location and amount of gains and losses reported in the statement of financial performance and (b) the location and fair value amounts of the instruments reported in the statement of financial position.
+ References
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