| **Fair Value Disclosures (Details 2) (Level 3, USD $)In Millions, unless otherwise specified**                         | 12 Months Ended |
|------------------------------------------------------------------------------------------------------------------------|-----------------|
||
| Securitized Retained Interests                                                                                         |            |   |   |
| **Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]** |            |   |   |
| Balance at beginning of year                                                                                           | $ 0             | $ 0 | $ 102 |
| Adjustment to adopt consolidation of variable-interest entities                                                        |            |   | (102) |
| Issuance of guarantees                                                                                                 | 0               | 0 | 0 |
| Expiration of guarantees                                                                                               | 0               | 0 | 0 |
| Balance at end of year                                                                                                 | 0               | 0 | 0 |
| Guarantees                                                                                                             |            |   |   |
| **Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]** |            |   |   |
| Balance at beginning of year                                                                                           | 2               | 3 | 4 |
| Adjustment to adopt consolidation of variable-interest entities                                                        |            |   | 0 |
| Issuance of guarantees                                                                                                 | 2               | 4 | 7 |
| Expiration of guarantees                                                                                               | (2)             | (5) | (8) |
| Balance at end of year                                                                                                 | $ 2             | $ 2 | $ 3 |

| X                                                                                                                                                                                                                                                                                                                                                                                                                            |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
This element represents the fair value adjustments made to adopt accounting for variable interest entities.
+ References
No definition available.
+ Details**Name:**cfsc_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAdjustmentToAdoptAccountingForVariableInterestEntity**Namespace Prefix:**cfsc_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                         |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Expiration of liabilities during the period in relation to liabilities measured at fair value and categorized within Level 3 of the fair value hierarchy.
+ References
No definition available.
+ Details**Name:**cfsc_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityExpiration**Namespace Prefix:**cfsc_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**duration |
| X                                                                                                                                                                                                                                     |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward**Namespace Prefix:**us-gaap_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Issues that have taken place during the period in relation to liabilities measured at fair value and categorized within Level 3 of the fair value hierarchy.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19207-110258
+ Details**Name:**us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityIssues**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
This element represents a liability measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19207-110258
+ Details**Name:**us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**instant |