| **Accumulated Other Comprehensive Income/(Loss)**                        | 12 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
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| **Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]** |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
| Accumulated Other Comprehensive Income/(Loss)                            | ACCUMULATED OTHER COMPREHENSIVE INCOME/(LOSS)Comprehensive income/(loss) and its components are presented in the Consolidated Statements of Comprehensive Income.  Changes in Accumulated other comprehensive income/(loss), net of tax, included in the Consolidated Statements of Changes in Stockholder's Equity, consisted of the following:(Millions of dollars)Foreign currency translation Derivative financial instruments Total      Balance at December 31, 2012$184 $(8) $176Other comprehensive income/(loss) before reclassifications(62) (1) (63)Amounts reclassified from accumulated other comprehensive (income)/loss— 4 4Other comprehensive income/(loss)(62) 3 (59)Balance at December 31, 2013$122 $(5) $117Other comprehensive income/(loss) before reclassifications(481) (4) (485)Amounts reclassified from accumulated other comprehensive (income)/loss— 4 4Other comprehensive income/(loss)(481) — (481)Balance at December 31, 2014$(359) $(5) $(364)Other comprehensive income/(loss) before reclassifications(538) 2 (536)Amounts reclassified from accumulated other comprehensive (income)/loss— 3 3Other comprehensive income/(loss)(538) 5 (533)Balance at December 31, 2015$(897) $— $(897)      The effect of the reclassifications out of Accumulated other comprehensive income/(loss) on the Consolidated Statements of Profit during the years ended December 31, 2015, 2014 and 2013 was as follows:(Millions of dollars)        Classification of income (expense) 2015 2014 2013Cross currency contractsOther income (expense) $1 $— $—Interest rate contractsInterest expense (6) (6) (6)Reclassifications before tax  (5) (6) (6)Tax (provision) benefit  2 2 2Total reclassifications from Accumulated other comprehensive income/(loss) $(3) $(4) $(4)         |

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No definition available.
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| - Definition
The entire disclosure for comprehensive income, which includes, but is not limited to, 1) the amount of income tax expense or benefit allocated to each component of other comprehensive income, including reclassification adjustments, 2) the reclassification adjustments for each classification of other comprehensive income and 3) the ending accumulated balances for each component of comprehensive income.
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