Amount of lessee's undiscounted obligation for lease payment for operating lease.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 6
-URI https://asc.fasb.org/extlink&oid=128292326&loc=SL77918701-209980

+ Details

Name:	us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Term of lessee's operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (a)(3)
-URI https://asc.fasb.org/extlink&oid=128292326&loc=SL77918673-209980

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

Name:	us-gaap_LettersOfCreditOutstandingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of operating lease expense. Excludes sublease income.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 45
-Paragraph 4
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=123391704&loc=SL77918638-209977

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of increase in right-of-use asset obtained in exchange for operating lease liability.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 55
-Paragraph 53
-URI https://asc.fasb.org/extlink&oid=123414884&loc=SL77918982-209971

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (g)(2)
-URI https://asc.fasb.org/extlink&oid=128292326&loc=SL77918686-209980

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LeaseContractualTermAxis=crmt_ReasonablyAssuredMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LeaseContractualTermAxis=crmt_DealershipLeasesMember
Namespace Prefix:
Data Type:	na
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- Details

Name:	srt_RangeAxis=srt_MaximumMember
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Note L - Commitments and Contingencies (Details Textual) - USD ($)	12 Months Ended
	Apr. 30, 2022	Apr. 30, 2021	Apr. 30, 2020	Jan. 31, 2022
Letters of Credit Outstanding, Amount	$ 750,000
Lessee, Operating Lease, Liability, to be Paid, Total	81,949,000
Operating Lease, Expense	8,000,000.0	$ 8,000,000.0	$ 6,900,000
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	7,900,000
Non-cancelable [Member]
Lessee, Operating Lease, Liability, to be Paid, Total	18,000,000.0
Reasonably Assured [Member]
Lessee, Operating Lease, Liability, to be Paid, Total	$ 63,900,000
Minimum [Member]
Lessee, Operating Lease, Term of Contract (Year)	3 years
Minimum [Member] \| Dealership Leases [Member]
Lessee, Operating Lease, Term of Contract (Year)				3 years
Maximum [Member]
Lessee, Operating Lease, Term of Contract (Year)	10 years
Maximum [Member] \| Dealership Leases [Member]
Lessee, Operating Lease, Term of Contract (Year)				5 years