| **Derivative Financial Instruments and Risk Management (Details 5) (USD $)In Millions, unless otherwise specified** | 3 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                   |
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| Designated derivatives | Fair value hedges | Interest rate contracts | Other income (expense)                       |                                                                                                                                                                                                                                                                                                                                                                                                                                             |   |
| **Derivative Instruments, Gain (Loss)**                                                                             |                                                                                                                                                                                                                                                                                                                                                                                                                                             |   |
| Gains (Losses) on Derivatives                                                                                       | $ (1)us-gaap_ChangeInUnrealizedGainLossOnFairValueHedgingInstruments1/ us-gaap_DerivativeInstrumentRiskAxis= us-gaap_InterestRateContractMember/ us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis= us-gaap_FairValueHedgingMember/ us-gaap_HedgingDesignationAxis= us-gaap_DesignatedAsHedgingInstrumentMember/ us-gaap_IncomeStatementLocationAxis= cfsc_OtherIncomeExpenseMember                                                 | $ (13)us-gaap_ChangeInUnrealizedGainLossOnFairValueHedgingInstruments1/ us-gaap_DerivativeInstrumentRiskAxis= us-gaap_InterestRateContractMember/ us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis= us-gaap_FairValueHedgingMember/ us-gaap_HedgingDesignationAxis= us-gaap_DesignatedAsHedgingInstrumentMember/ us-gaap_IncomeStatementLocationAxis= cfsc_OtherIncomeExpenseMember |
| Gains (Losses) on Borrowings                                                                                        | 1us-gaap_ChangeInUnrealizedGainLossOnHedgedItemInFairValueHedge1/ us-gaap_DerivativeInstrumentRiskAxis= us-gaap_InterestRateContractMember/ us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis= us-gaap_FairValueHedgingMember/ us-gaap_HedgingDesignationAxis= us-gaap_DesignatedAsHedgingInstrumentMember/ us-gaap_IncomeStatementLocationAxis= cfsc_OtherIncomeExpenseMember                                                      | 13us-gaap_ChangeInUnrealizedGainLossOnHedgedItemInFairValueHedge1/ us-gaap_DerivativeInstrumentRiskAxis= us-gaap_InterestRateContractMember/ us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis= us-gaap_FairValueHedgingMember/ us-gaap_HedgingDesignationAxis= us-gaap_DesignatedAsHedgingInstrumentMember/ us-gaap_IncomeStatementLocationAxis= cfsc_OtherIncomeExpenseMember |
| Designated derivatives | Cash flow hedges | Interest rate contracts                                                 |                                                                                                                                                                                                                                                                                                                                                                                                                                             |   |
| **Derivative Instruments, Gain (Loss)**                                                                             |                                                                                                                                                                                                                                                                                                                                                                                                                                             |   |
| Amount of Gains (Losses) Reclassified from AOCI to Earnings (Effective Portion)                                     | (1)us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet/ us-gaap_DerivativeInstrumentRiskAxis= us-gaap_InterestRateContractMember/ us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis= us-gaap_CashFlowHedgingMember/ us-gaap_HedgingDesignationAxis= us-gaap_DesignatedAsHedgingInstrumentMember                                                                                        | (1)us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet/ us-gaap_DerivativeInstrumentRiskAxis= us-gaap_InterestRateContractMember/ us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis= us-gaap_CashFlowHedgingMember/ us-gaap_HedgingDesignationAxis= us-gaap_DesignatedAsHedgingInstrumentMember |
| Recognized in Earnings (Ineffective Portion)                                                                        | 0us-gaap_DerivativeInstrumentsGainLossRecognizedInIncomeIneffectivePortionAndAmountExcludedFromEffectivenessTestingNet/ us-gaap_DerivativeInstrumentRiskAxis= us-gaap_InterestRateContractMember/ us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis= us-gaap_CashFlowHedgingMember/ us-gaap_HedgingDesignationAxis= us-gaap_DesignatedAsHedgingInstrumentMember                                                                     | 0us-gaap_DerivativeInstrumentsGainLossRecognizedInIncomeIneffectivePortionAndAmountExcludedFromEffectivenessTestingNet/ us-gaap_DerivativeInstrumentRiskAxis= us-gaap_InterestRateContractMember/ us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis= us-gaap_CashFlowHedgingMember/ us-gaap_HedgingDesignationAxis= us-gaap_DesignatedAsHedgingInstrumentMember |
| Designated derivatives | Cash flow hedges | Interest rate contracts | Interest expense                              |                                                                                                                                                                                                                                                                                                                                                                                                                                             |   |
| **Derivative Instruments, Gain (Loss)**                                                                             |                                                                                                                                                                                                                                                                                                                                                                                                                                             |   |
| Amount of Gains (Losses) Reclassified from AOCI to Earnings (Effective Portion)                                     | (1)us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet/ us-gaap_DerivativeInstrumentRiskAxis= us-gaap_InterestRateContractMember/ us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis= us-gaap_CashFlowHedgingMember/ us-gaap_HedgingDesignationAxis= us-gaap_DesignatedAsHedgingInstrumentMember/ us-gaap_IncomeStatementLocationAxis= us-gaap_InterestExpenseMember                    | (1)us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet/ us-gaap_DerivativeInstrumentRiskAxis= us-gaap_InterestRateContractMember/ us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis= us-gaap_CashFlowHedgingMember/ us-gaap_HedgingDesignationAxis= us-gaap_DesignatedAsHedgingInstrumentMember/ us-gaap_IncomeStatementLocationAxis= us-gaap_InterestExpenseMember |
| Recognized in Earnings (Ineffective Portion)                                                                        | 0us-gaap_DerivativeInstrumentsGainLossRecognizedInIncomeIneffectivePortionAndAmountExcludedFromEffectivenessTestingNet/ us-gaap_DerivativeInstrumentRiskAxis= us-gaap_InterestRateContractMember/ us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis= us-gaap_CashFlowHedgingMember/ us-gaap_HedgingDesignationAxis= us-gaap_DesignatedAsHedgingInstrumentMember/ us-gaap_IncomeStatementLocationAxis= us-gaap_InterestExpenseMember | 0us-gaap_DerivativeInstrumentsGainLossRecognizedInIncomeIneffectivePortionAndAmountExcludedFromEffectivenessTestingNet/ us-gaap_DerivativeInstrumentRiskAxis= us-gaap_InterestRateContractMember/ us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis= us-gaap_CashFlowHedgingMember/ us-gaap_HedgingDesignationAxis= us-gaap_DesignatedAsHedgingInstrumentMember/ us-gaap_IncomeStatementLocationAxis= us-gaap_InterestExpenseMember |
| Designated derivatives | Cash flow hedges | Interest rate contracts | Other income (expense)                        |                                                                                                                                                                                                                                                                                                                                                                                                                                             |   |
| **Derivative Instruments, Gain (Loss)**                                                                             |                                                                                                                                                                                                                                                                                                                                                                                                                                             |   |
| Amount of Gains (Losses) Reclassified from AOCI to Earnings (Effective Portion)                                     | 0us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet/ us-gaap_DerivativeInstrumentRiskAxis= us-gaap_InterestRateContractMember/ us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis= us-gaap_CashFlowHedgingMember/ us-gaap_HedgingDesignationAxis= us-gaap_DesignatedAsHedgingInstrumentMember/ us-gaap_IncomeStatementLocationAxis= cfsc_OtherIncomeExpenseMember                      | 0us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet/ us-gaap_DerivativeInstrumentRiskAxis= us-gaap_InterestRateContractMember/ us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis= us-gaap_CashFlowHedgingMember/ us-gaap_HedgingDesignationAxis= us-gaap_DesignatedAsHedgingInstrumentMember/ us-gaap_IncomeStatementLocationAxis= cfsc_OtherIncomeExpenseMember |
| Recognized in Earnings (Ineffective Portion)                                                                        | 0us-gaap_DerivativeInstrumentsGainLossRecognizedInIncomeIneffectivePortionAndAmountExcludedFromEffectivenessTestingNet/ us-gaap_DerivativeInstrumentRiskAxis= us-gaap_InterestRateContractMember/ us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis= us-gaap_CashFlowHedgingMember/ us-gaap_HedgingDesignationAxis= us-gaap_DesignatedAsHedgingInstrumentMember/ us-gaap_IncomeStatementLocationAxis= cfsc_OtherIncomeExpenseMember | 0us-gaap_DerivativeInstrumentsGainLossRecognizedInIncomeIneffectivePortionAndAmountExcludedFromEffectivenessTestingNet/ us-gaap_DerivativeInstrumentRiskAxis= us-gaap_InterestRateContractMember/ us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis= us-gaap_CashFlowHedgingMember/ us-gaap_HedgingDesignationAxis= us-gaap_DesignatedAsHedgingInstrumentMember/ us-gaap_IncomeStatementLocationAxis= cfsc_OtherIncomeExpenseMember |
| Undesignated derivatives                                                                                            |                                                                                                                                                                                                                                                                                                                                                                                                                                             |   |
| **Derivative Instruments, Gain (Loss)**                                                                             |                                                                                                                                                                                                                                                                                                                                                                                                                                             |   |
| Gains (Losses) on Derivatives Not Designated as Hedging Instruments                                                 | (28)us-gaap_DerivativeGainLossOnDerivativeNet/ us-gaap_HedgingDesignationAxis= us-gaap_NondesignatedMember                                                                                                                                                                                                                                                                                                                                       | (5)us-gaap_DerivativeGainLossOnDerivativeNet/ us-gaap_HedgingDesignationAxis= us-gaap_NondesignatedMember |
| Undesignated derivatives | Foreign exchange contracts | Other income (expense)                                      |                                                                                                                                                                                                                                                                                                                                                                                                                                             |   |
| **Derivative Instruments, Gain (Loss)**                                                                             |                                                                                                                                                                                                                                                                                                                                                                                                                                             |   |
| Gains (Losses) on Derivatives Not Designated as Hedging Instruments                                                 | (38)us-gaap_DerivativeGainLossOnDerivativeNet/ us-gaap_DerivativeInstrumentRiskAxis= us-gaap_ForeignExchangeContractMember/ us-gaap_HedgingDesignationAxis= us-gaap_NondesignatedMember/ us-gaap_IncomeStatementLocationAxis= cfsc_OtherIncomeExpenseMember                                                                                                                                                                                      | (1)us-gaap_DerivativeGainLossOnDerivativeNet/ us-gaap_DerivativeInstrumentRiskAxis= us-gaap_ForeignExchangeContractMember/ us-gaap_HedgingDesignationAxis= us-gaap_NondesignatedMember/ us-gaap_IncomeStatementLocationAxis= cfsc_OtherIncomeExpenseMember |
| Undesignated derivatives | Cross currency contracts | Other income (expense)                                        |                                                                                                                                                                                                                                                                                                                                                                                                                                             |   |
| **Derivative Instruments, Gain (Loss)**                                                                             |                                                                                                                                                                                                                                                                                                                                                                                                                                             |   |
| Gains (Losses) on Derivatives Not Designated as Hedging Instruments                                                 | $ 10us-gaap_DerivativeGainLossOnDerivativeNet/ us-gaap_DerivativeInstrumentRiskAxis= us-gaap_CrossCurrencyInterestRateContractMember/ us-gaap_HedgingDesignationAxis= us-gaap_NondesignatedMember/ us-gaap_IncomeStatementLocationAxis= cfsc_OtherIncomeExpenseMember                                                                                                                                                                            | $ (4)us-gaap_DerivativeGainLossOnDerivativeNet/ us-gaap_DerivativeInstrumentRiskAxis= us-gaap_CrossCurrencyInterestRateContractMember/ us-gaap_HedgingDesignationAxis= us-gaap_NondesignatedMember/ us-gaap_IncomeStatementLocationAxis= cfsc_OtherIncomeExpenseMember |

| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
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| - Definition
Amount of gain (loss) from the increase (decrease) in fair value of derivative and nonderivative instruments designated as fair value hedging instruments recognized in the income statement.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 25 -Section 50 -Paragraph 1 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=6886632&loc=d3e76258-113986
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
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| - Definition
Amount of the increase (decrease) in fair value of the hedged item in a fair value hedge recognized in the income statement.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 25 -Section 50 -Paragraph 1 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=6886632&loc=d3e76258-113986
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
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| - Definition
Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.
+ References
Reference 1: 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=35706170&loc=SL5618551-113959Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (a),(c),(d),(e) -URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5624171-113959
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
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| - Definition
The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying 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 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5624171-113959Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4D -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5624177-113959
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
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| - Definition
The portion of gains and losses (net) on derivative instruments designated and qualifying as hedging instruments representing (a) the amount of the hedge ineffectiveness and (b) the amount, if any, excluded from the assessment of hedge effectiveness.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5624171-113959Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 25 -Section 50 -Paragraph 1 -Subparagraph (a)(1),(2) -URI http://asc.fasb.org/extlink&oid=6886632&loc=d3e76258-113986
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| - Details**Name:**us-gaap_HedgingDesignationAxis=us-gaap_DesignatedAsHedgingInstrumentMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                                  |
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