| **Finance Receivables (Details) - USD ($) $ in Millions** | Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 |
|-----------------------------------------------------------|---------------|---------------|---------------|
| **Accounts, Notes, Loans and Financing Receivable**       |          |          |          |
| Recorded Investment in Finance Receivables                | $ 28,434      | $ 27,491      |          |
| Less: Allowance for credit losses                         | (511)         | (365)         | $ (343)       |
| Total finance receivables, net                            | 27,923        | 27,126        |          |
| Retail loans                                              |          |          |          |
| **Accounts, Notes, Loans and Financing Receivable**       |          |          |          |
| Recorded Investment in Finance Receivables                | 15,509        | 16,142        |          |
| Retail leases                                             |          |          |          |
| **Accounts, Notes, Loans and Financing Receivable**       |          |          |          |
| Recorded Investment in Finance Receivables                | 7,499         | 7,111         |          |
| Caterpillar purchased receivables                         |          |          |          |
| **Accounts, Notes, Loans and Financing Receivable**       |          |          |          |
| Recorded Investment in Finance Receivables                | 4,691         | 3,461         |          |
| Wholesale loans                                           |          |          |          |
| **Accounts, Notes, Loans and Financing Receivable**       |          |          |          |
| Recorded Investment in Finance Receivables                | 626           | 691           |          |
| Wholesale leases                                          |          |          |          |
| **Accounts, Notes, Loans and Financing Receivable**       |          |          |          |
| Recorded Investment in Finance Receivables                | $ 109         | $ 86          |          |

| 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_AccountsNotesAndLoansReceivableLineItems**Namespace Prefix:**us-gaap_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
A valuation allowance for financing receivables that are expected to be uncollectible.
+ References
Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524
+ Details**Name:**us-gaap_FinancingReceivableAllowanceForCreditLosses**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount before allowance and after deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements.
+ References
Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=82891408&loc=d3e4428-111522Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5074-111524
+ Details**Name:**us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements and loans held for sale.
+ References
Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=82891408&loc=d3e4428-111522Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.7) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878
+ Details**Name:**us-gaap_LoansAndLeasesReceivableNetReportedAmount**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**instant |
| X                                                                                                                                                                                   |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=cfsc_RetailloansMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                                                                    |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=cfsc_RetailleasesMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                                                                                       |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=cfsc_CaterpillarPurchasedReceivablesMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                                                                      |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=cfsc_WholesaleloansMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                                                                       |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=cfsc_WholesaleleasesMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |