XML 50 R39.htm IDEA: XBRL DOCUMENT v3.23.3

Description of Business (Percentage of Consumer Loans Assigned with FICO Score of Less Than 650 or No FICO Score) (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Percentage Of Contracts With FICO Score Lower Than 650 Or No FICO Score [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Percentage Of Contracts	78.60%	84.20%	81.50%	85.60%

X

- Definition

Percentage Of Contracts

+ References

No definition available.

+ Details

Name:	cacc_PercentageOfContracts
Namespace Prefix:	cacc_
Data Type:	dtr-types1:percentItemType
Balance Type:	na
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

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479319/326-20-50-5

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 79
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479294/326-20-55-79

+ Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_CreditScoreFicoAxis=cacc_FICOScoreLowerThan650OrNoFICOScoreMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: