Note C - Finance Receivables, Net - Financing Receivables Analysis (Details)	9 Months Ended
Jan. 31, 2018	Jan. 31, 2017
Principal collected as a percent of average finance receivables	37.20%	37.90%
Average down-payment percentage	5.80%	5.30%
Average originating contract term (in months) (Month)	2 years 168 days	2 years 159 days

Represents the principal collected as a percent of average finance receivables.

No definition available.

Name:	crmt_PrincipalCollectedAsAPercentOfAverageFinancingReceivables
Namespace Prefix:	crmt_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant