XML 55 R43.htm IDEA: XBRL DOCUMENT
v3.24.2

Summary of Significant Accounting Policies (Narrative) (Details) $ in Millions | 6 Months Ended |
--- | --- | ---
Jun. 30, 2024 USD ($) segment | Dec. 31, 2023 USD ($)
Summary Of Significant Accounting Policies [Line Items] |  |
Number of reportable segments | segment | 1 |
Cash and Cash Equivalents [Member] |  |
Summary Of Significant Accounting Policies [Line Items] |  |
Uninsured cash and cash equivalents | $ 8.0 | $ 12.8
Restricted Cash and Cash Equivalents [Member] |  |
Summary Of Significant Accounting Policies [Line Items] |  |
Uninsured cash and cash equivalents | $ 504.5 | $ 453.7

X
- Definition Summary Of Significant Accounting Policies [Line Items] + References No definition available. + Details
Name: | cacc_SummaryOfSignificantAccountingPoliciesLineItems
Namespace Prefix: | cacc_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount of cash as of the balance sheet date that is not insured by the Federal Deposit Insurance Corporation. + References No definition available. + Details
Name: | us-gaap_CashUninsuredAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 47 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482785/280-10-55-47 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 54 -Subparagraph (e) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482785/280-10-55-54 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 18 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482810/280-10-50-18 + Details
Name: | us-gaap_NumberOfReportableSegments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_CashAndCashEquivalentsAxis=us-gaap_CashAndCashEquivalentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CashAndCashEquivalentsAxis=cacc_RestrictedCashAndCashEquivalentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |