| **Credit Commitments (Details) $ in Millions**                                | 6 Months Ended | 12 Months Ended |         |         |
|-------------------------------------------------------------------------------|----------------|-----------------|---------|---------|
||
| **Line of Credit Facility**                                                   |           |            |    |    |
| Number of global credit facilities                                            | 3              | 3               |    |    |
| Caterpillar's consolidated net worth                                          | $ 19,920       | $ 19,920        |    |    |
| Minimum net worth required under the Credit Facility                          | $ 9,000        | $ 9,000         |    |    |
| Covenant interest coverage ratio, Numerator                                   |           | 2.05            |    |    |
| Covenant interest coverage ratio, Denominator                                 |           | 1               |    |    |
| Minimum interest coverage ratio, required by the Credit Facility, Numerator   |           | 1.15            |    |    |
| Minimum interest coverage ratio, required by the Credit Facility, Denominator |           | 1               |    |    |
| Leverage Ratio, Numerator                                                     | 7.49           | 7.93            |    |    |
| Leverage Ratio, Denominator                                                   | 1              | 1               |    |    |
| Maximum Leverage Ratio, Permissible Under Credit Facility, Numerator          |           | 10              |    |    |
| Maximum Leverage Ratio, Permissible Under Credit Facility, Denominator        |           | 1               |    |    |
| Amount available                                                              | $ 10,500       | $ 10,500        |    |    |
| Maximum borrowing capacity from Caterpillar, Variable lending agreements      | 2,280          | 2,280           |    |    |
| Maximum lending capacity to Caterpillar, Variable lending agreements          | 1,290          | 1,290           |    |    |
| Notes receivable from Caterpillar                                             | 490            | 490             | $ 414   | $ 345   |
| Notes payable to Caterpillar                                                  | 1,096          | 1,096           | 1,108   | $ 1,118 |
| Amount available, Committed credit facility extended to Caterpillar           | 2,000          | 2,000           |    |    |
| Amount outstanding, Committed credit facility extended to Caterpillar         | 0              | 0               |    |    |
| Revolving credit facilities                                                   |           |            |    |    |
| **Line of Credit Facility**                                                   |           |            |    |    |
| Amount outstanding                                                            | 0              | 0               |    |    |
| Revolving credit facilities | Cat Financial                                   |           |            |    |    |
| **Line of Credit Facility**                                                   |           |            |    |    |
| Amount available                                                              | 7,750          | 7,750           |    |    |
| 364-day facility                                                              |           |            |    |    |
| **Line of Credit Facility**                                                   |           |            |    |    |
| Amount available                                                              | 3,150          | 3,150           |    |    |
| 364-day facility | Cat Financial                                              |           |            |    |    |
| **Line of Credit Facility**                                                   |           |            |    |    |
| Amount available                                                              | 2,330          | 2,330           |    |    |
| Three-year facility                                                           |           |            |    |    |
| **Line of Credit Facility**                                                   |           |            |    |    |
| Amount available                                                              | 2,730          | 2,730           |    |    |
| Three-year facility | Cat Financial                                           |           |            |    |    |
| **Line of Credit Facility**                                                   |           |            |    |    |
| Amount available                                                              | 2,010          | 2,010           |    |    |
| Five-year facility                                                            |           |            |    |    |
| **Line of Credit Facility**                                                   |           |            |    |    |
| Amount available                                                              | 4,620          | 4,620           |    |    |
| Five-year facility | Cat Financial                                            |           |            |    |    |
| **Line of Credit Facility**                                                   |           |            |    |    |
| Amount available                                                              | 3,410          | 3,410           |    |    |
| Credit lines with banks                                                       |           |            |    |    |
| **Line of Credit Facility**                                                   |           |            |    |    |
| Amount available                                                              | 3,570          | 3,570           |    |    |
| Amount outstanding                                                            | $ 1,440        | $ 1,440         | $ 1,900 |    |

| X                                                                                                                                                                                                                                                                                                                |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Maximum borrowing capacity under the committed credit facility with parent entity.
+ References
No definition available.
+ Details**Name:**cfsc_CommittedCreditFacilityWithParentEntity**Namespace Prefix:**cfsc_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                   |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount borrowed under the committed credit facility with parent entity as of the balance sheet date.
+ References
No definition available.
+ Details**Name:**cfsc_CommittedCreditFacilityWithParentEntityAmountOutstanding**Namespace Prefix:**cfsc_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Represents the denominator for interest coverage ratio used to measure of the number of times an entity could make the interest payments on its debt with its earnings before interest and taxes (EBIT) and before net gain/loss from interest rate derivatives. To calculate the interest coverage ratio, divide by the total interest expense.
+ References
No definition available.
+ Details**Name:**cfsc_InterestCoverageRatioDenominator**Namespace Prefix:**cfsc_**Data Type:**xbrli:pureItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Represents the numerator for interest coverage ratio used to measure of the number of times an entity could make the interest payments on its debt with its earnings before interest and taxes (EBIT) and before net gain/loss from interest rate derivatives. To calculate the interest coverage ratio, divide by the total interest expense.
+ References
No definition available.
+ Details**Name:**cfsc_InterestCoverageRatioNumerator**Namespace Prefix:**cfsc_**Data Type:**xbrli:pureItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                              |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Represents the denominator for the leverage ratio used to measure the entity's ability to meet its financial obligations. The leverage ratio is calculated by dividing the total debt by total equity.
+ References
No definition available.
+ Details**Name:**cfsc_LeverageRatioDenominator**Namespace Prefix:**cfsc_**Data Type:**xbrli:pureItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                          |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Represents the numerator for the leverage ratio used to measure the entity's ability to meet its financial obligations. The leverage ratio is calculated by dividing the total debt by total equity.
+ References
No definition available.
+ Details**Name:**cfsc_LeverageRatioNumerator**Namespace Prefix:**cfsc_**Data Type:**xbrli:pureItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                   |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
This element represents the number of global credit facilities.
+ References
No definition available.
+ Details**Name:**cfsc_LineOfCreditFacilityNumberOfGlobalCreditFacilities**Namespace Prefix:**cfsc_**Data Type:**xbrli:integerItemType**Balance Type:**na**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                            |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Maximum borrowing capacity under the variable lending agreements with parent entity.
+ References
No definition available.
+ Details**Name:**cfsc_MaximumBorrowingCapacityVariableLendingAgreementsWithParentEntity**Namespace Prefix:**cfsc_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                               |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Maximum lending capacity under variable lending agreements to parent entity.
+ References
No definition available.
+ Details**Name:**cfsc_MaximumLendingCapacityVariableLendingAgreementsToParentEntity**Namespace Prefix:**cfsc_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                     |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Represents the denominator for the leverage ratio permissible under the credit facility.
+ References
No definition available.
+ Details**Name:**cfsc_MaximumLeverageRatioPermissibleUnderCreditFacilityDenominator**Namespace Prefix:**cfsc_**Data Type:**xbrli:pureItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                 |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Represents the numerator for the leverage ratio permissible under the credit facility.
+ References
No definition available.
+ Details**Name:**cfsc_MaximumLeverageRatioPermissibleUnderCreditFacilityNumerator**Namespace Prefix:**cfsc_**Data Type:**xbrli:pureItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                             |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Represents the denominator of interest coverage ratio required under the credit facility.
+ References
No definition available.
+ Details**Name:**cfsc_MinimumInterestCoverageRatioRequiredUnderCreditFacilitiesDenominator**Namespace Prefix:**cfsc_**Data Type:**xbrli:pureItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                              |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Represents the numerator for the interest coverage ratio required under the credit facility.
+ References
No definition available.
+ Details**Name:**cfsc_MinimumInterestCoverageRatioRequiredUnderCreditFacilitiesNumerator**Namespace Prefix:**cfsc_**Data Type:**xbrli:pureItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                      |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
This element represents the minimum amount of net worth, as defined in the credit facility agreements, required under the facilities.
+ References
No definition available.
+ Details**Name:**cfsc_MinimumNetWorthRequiredUnderCreditFacility**Namespace Prefix:**cfsc_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                          |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
This element represents the entity's net worth, as defined in the credit facility agreements, as of the balance sheet date.
+ References
No definition available.
+ Details**Name:**cfsc_NetWorth**Namespace Prefix:**cfsc_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.16) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.16) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19, 20, 22 -Article 5
+ Details**Name:**us-gaap_LineOfCredit**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**instant |
| 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_LineOfCreditFacilityLineItems**Namespace Prefix:**us-gaap_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19(b),22(b)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682
+ Details**Name:**us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The amount for notes payable (written promise to pay), due to related parties.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.17) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(k)(1)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 850 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864
+ Details**Name:**us-gaap_NotesPayableRelatedPartiesCurrentAndNoncurrent**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
For an unclassified balance sheet, amounts due from parties associated with the reporting entity as evidenced by a written promise to pay.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(k)(1)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.3) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 850 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Related Parties -URI http://asc.fasb.org/extlink&oid=16382449
+ Details**Name:**us-gaap_NotesReceivableRelatedParties**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**instant |
| X                                                                                                                                                        |
|----------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                   |
|-------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**dei_LegalEntityAxis=cfsc_CatFinancialMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                                   |
|-----------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_CreditFacilityAxis=cfsc_A364DayCreditFacilityMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                                     |
|-------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_CreditFacilityAxis=cfsc_ThreeyearcreditfacilityMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                                    |
|------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_CreditFacilityAxis=cfsc_FiveYearCreditFacilityMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                             |
|-----------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_CreditFacilityAxis=us-gaap_LineOfCreditMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |