|**Derivative Financial Instruments and Risk Management (Tables)**                                                                               | 9 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
|----------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|
|**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)September 30, 2023December 31, 2022Assets1Liabilities2Assets1Liabilities2Designated derivativesForeign exchange contracts$282$(61)$305$(44)Interest rate contracts52(109)87(113)$334$(170)$392$(157)Undesignated derivativesForeign exchange contracts$28$(35)$25$(42)$28$(35)$25$(42)(1)Assets are classified on the Consolidated Statements of Financial Position as Other assets.(2)Liabilities are classified on the Consolidated Statements of Financial Position as Accrued expenses.                                                                                                                                                                                                                                                                                                                                                    
|                                                                                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|                                                                                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|(Millions of dollars)                                                                                                                           |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|                                                                                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Designated derivatives                                                                                                                          |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Foreign exchange contracts                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Interest rate contracts                                                                                                                         |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|                                                                                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Undesignated derivatives                                                                                                                        |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Foreign exchange contracts                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|                                                                                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|                                                                                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Schedule of Gains (Losses) on derivatives instruments                                                                                           | Gains (Losses) on derivative instruments are categorized as follows:(Millions of dollars)Fair Value / Undesignated HedgesCash Flow HedgesGains (Losses)Recognized1Gains (Losses) Recognized in AOCIGains (Losses)Reclassified from AOCI2Three Months Ended September 30,202320222023202220232022Foreign exchange contracts$22$16$76$276$70$303Interest rate contracts(20)(5)326158$2$11$79$302$85$311Nine Months Ended September 30,202320222023202220232022Foreign exchange contracts$21$(26)$59$570$38$656Interest rate contracts(53)41510343—$(32)$(22)$74$673$81$656(1)Foreign exchange contract gains (losses) are primarily from undesignated forward contracts and are included in Other income (expense). Interest rate contract gains (losses) are from designated fair value hedges and are included in Interest expense.(2)Foreign exchange contract gains (losses) are primarily included in Other income (expense). Interest rate contract gains (losses) are included in Interest expense.
|                                                                                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|(Millions of dollars)                                                                                                                           |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|                                                                                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|                                                                                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|                                                                                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|                                                                                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Foreign exchange contracts                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Interest rate contracts                                                                                                                         |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|                                                                                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|                                                                                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|                                                                                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|                                                                                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Foreign exchange contracts                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Interest rate contracts                                                                                                                         |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|                                                                                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|                                                                                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Schedule of amounts recorded in the Consolidated Statements of Financial Position related to cumulative basis adjustments for fair value hedges | The following amounts were recorded in the Consolidated Statements of Financial Position related to cumulative basis adjustments for fair value hedges:(Millions of dollars)Carrying Value of the Hedged LiabilitiesCumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Value of the Hedged LiabilitiesSeptember 30, 2023December 31, 2022September 30, 2023December 31, 2022Current maturities of long-term debt$249$—$(4)$—Long-term debt2,7202,091(105)(112)Total$2,969$2,091$(109)$(112)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    
|                                                                                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|(Millions of dollars)                                                                                                                           |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|                                                                                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Current maturities of long-term debt                                                                                                            |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Long-term debt                                                                                                                                  |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Total                                                                                                                                           |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|                                                                                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Schedule of effect of net settlement provisions of the master netting agreements on our derivative balances                                     | 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:(Millions of dollars)September 30, 2023December 31, 2022AssetsLiabilitiesAssetsLiabilitiesGross amounts recognized$362$(205)$417$(199)Financial instruments not offset(122)122(108)108Net amount$240$(83)$309$(91)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
|                                                                                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|(Millions of dollars)                                                                                                                           |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|                                                                                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Gross amounts recognized                                                                                                                        |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Financial instruments not offset                                                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|                                                                                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|Net amount                                                                                                                                      |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
|                                                                                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         

X- DefinitionTabular disclosure of derivative and other financial assets and liabilities that are subject to offsetting, including master netting arrangements.
+ ReferencesNo definition available.
+ Details**Name:**
cfsc_OffsettingassetsandliabilitiesTableTextBlock**Namespace Prefix:**
cfsc_**Data Type:**
dtr-types1:textBlockItemType**Balance Type:**
na**Period Type:**
duration X- ReferencesNo definition available.
+ Details**Name:**
us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract**Namespace Prefix:**
us-gaap_**Data Type:**
xbrli:stringItemType**Balance Type:**
na**Period Type:**
duration X- DefinitionTabular 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.
+ ReferencesReference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4E -Publisher FASB -URI https://asc.fasb.org//1943274/2147480434/815-10-50-4EReference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Publisher FASB -URI https://asc.fasb.org//1943274/2147480434/815-10-50-4CReference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4A -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480434/815-10-50-4A
+ Details**Name:**
us-gaap_ScheduleOfDerivativeInstrumentsGainLossInStatementOfFinancialPerformanceTextBlock**Namespace Prefix:**
us-gaap_**Data Type:**
dtr-types:textBlockItemType**Balance Type:**
na**Period Type:**
duration X- DefinitionTabular 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.
+ ReferencesReference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4B -Publisher FASB -URI https://asc.fasb.org//1943274/2147480434/815-10-50-4B
+ Details**Name:**
us-gaap_ScheduleOfDerivativeInstrumentsInStatementOfFinancialPositionFairValueTextBlock**Namespace Prefix:**
us-gaap_**Data Type:**
dtr-types:textBlockItemType**Balance Type:**
na**Period Type:**
duration X- DefinitionTabular disclosure for fair value 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.
+ ReferencesReference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480434/815-10-50-4C
+ Details**Name:**
us-gaap_ScheduleOfFairValueHedgingInstrumentsStatementsOfFinancialPerformanceAndFinancialPositionLocationTableTextBlock**Namespace Prefix:**
us-gaap_**Data Type:**
dtr-types:textBlockItemType**Balance Type:**
na**Period Type:**
duration