| **Finance Receivables (Details 5) - USD ($) $ in Millions**      | Jun. 30, 2018 | Dec. 31, 2017 |
|------------------------------------------------------------------|---------------|---------------|
| **Financing Receivable, Recorded Investment, Past Due**          |          |          |
| Recorded investment in finance receivables on non-accrual status | $ 629         | $ 683         |
| Customer | North America                                         |          |          |
| **Financing Receivable, Recorded Investment, Past Due**          |          |          |
| Recorded investment in finance receivables on non-accrual status | 42            | 38            |
| Customer | Europe                                                |          |          |
| **Financing Receivable, Recorded Investment, Past Due**          |          |          |
| Recorded investment in finance receivables on non-accrual status | 69            | 37            |
| Customer | Asia/Pacific                                          |          |          |
| **Financing Receivable, Recorded Investment, Past Due**          |          |          |
| Recorded investment in finance receivables on non-accrual status | 6             | 10            |
| Customer | Mining                                                |          |          |
| **Financing Receivable, Recorded Investment, Past Due**          |          |          |
| Recorded investment in finance receivables on non-accrual status | 13            | 63            |
| Customer | Latin America                                         |          |          |
| **Financing Receivable, Recorded Investment, Past Due**          |          |          |
| Recorded investment in finance receivables on non-accrual status | 142           | 192           |
| Customer | Caterpillar Power Finance                             |          |          |
| **Financing Receivable, Recorded Investment, Past Due**          |          |          |
| Recorded investment in finance receivables on non-accrual status | 357           | 343           |
| Dealer                                                           |          |          |
| **Financing Receivable, Recorded Investment, Past Due**          |          |          |
| Recorded investment in finance receivables on non-accrual status |          | $ 0           |
| Dealer | Latin America                                           |          |          |
| **Financing Receivable, Recorded Investment, Past Due**          |          |          |
| Recorded investment in finance receivables on non-accrual status | $ 77          |          |

| X                                                                                                                                                                                                                                                                                                                                                                                                                                             |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.
+ References
No definition available.
+ Details**Name:**us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems**Namespace Prefix:**us-gaap_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                   |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Reflects the carrying amount of loans deemed to be questionable as to collection on which interest is continuing to be earned or accrued.
+ References
No definition available.
+ Details**Name:**us-gaap_LoansAndLeasesReceivableImpairedNonperformingAccrualOfInterest**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**instant |
| X                                                                                                                                                           |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_FinancingReceivablePortfolioSegmentAxis=cfsc_CustomerMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                                                                                |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_NorthAmericaMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                                                                        |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_EMEAMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                                                                               |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_AsiaPacificMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                                                                       |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=cfsc_MiningMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                                                                                |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_LatinAmericaMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                                                                                        |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=cfsc_CaterpillarPowerFinanceMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                                         |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_FinancingReceivablePortfolioSegmentAxis=cfsc_DealerMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |