XML 67 R52.htm IDEA: XBRL DOCUMENT
v3.20.4

Loans Receivable (Narrative) (Details) - USD ($) $ in Millions | 3 Months Ended | 12 Months Ended
--- | --- | ---
Mar. 31, 2020 | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Transfers | [1] |  | $ 0.0 | $ 0.0 | $ 0.0
Forecast changes |  | $ (206.5) | (46.3) | 14.6 | 42.3
Certain Loans Acquired In Transfer Accounted For As Loans Accretable Yield Reclassifications From Nonaccretable Difference Forecast Changes, By Percentage |  | 2.30% |  |  |
Forecast Changes [Member] |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Forecast changes |  | $ (44.3) |  |  |
COVID-19 Adjustment [Member] |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Forecast changes |  |  | (162.2) |  |
Dealer Loans [Member] |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Transfers | [1] |  | 80.1 | 74.1 | 64.5
Forecast changes |  |  | (41.1) | (7.9) | 2.0
Purchased Loans [Member] |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Transfers | [1] |  | 80.1 | 74.1 | 64.5
Forecast changes |  |  | $ (5.2) | $ 22.5 | $ 40.3
[1] | Under our Portfolio Program, certain events may result in Dealers forfeiting their rights to Dealer Holdback. We transfer the Dealer’s outstanding Dealer Loan balance and related allowance for credit losses balance to Purchased Loans in the period this forfeiture occurs.

X
- Definition Change in the estimate of cash flows expected to be collected, after acquisition of a loan, which results in an increase in accretable yield (for example, if actual cash flows are significantly greater than previously expected). This relates to loans with evidence of deterioration of credit quality since origination that was acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable. + References No definition available. + Details
Name: | cacc_CertainLoansAcquiredInTransferAccountedForAsLoansAccretableYieldReclassificationsFromNonaccretableDifferenceForecastChanges
Namespace Prefix: | cacc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Certain Loans Acquired In Transfer Accounted For As Loans Accretable Yield Reclassifications From Nonaccretable Difference Forecast Changes, By Percentage + References No definition available. + Details
Name: | cacc_CertainLoansAcquiredInTransferAccountedForAsLoansAccretableYieldReclassificationsFromNonaccretableDifferenceForecastChangesByPercentage
Namespace Prefix: | cacc_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Loans and leases receivable transfers. + References No definition available. + Details
Name: | cacc_LoansAndLeasesReceivableTransfers
Namespace Prefix: | cacc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

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
- Details
Name: | us-gaap_UnusualOrInfrequentItemAxis=cacc_ForecastChangesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_UnusualOrInfrequentItemAxis=cacc_COVID19AdjustmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=cacc_DealerLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=cacc_PurchasedLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |