Note B - Summary of Significant Accounting Policies - Sales (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Jan. 31, 2020	Jan. 31, 2019	Jan. 31, 2020	Jan. 31, 2019
Sales	$ 163,253	$ 139,803	$ 481,070	$ 430,315
Sales Used Autos [Member]
Sales	142,136	119,955	417,079	371,465
Wholesales Third Party [Member]
Sales	6,810	6,460	22,236	19,205
Service Contract Sales [Member]
Sales	7,983	7,600	23,283	22,655
Payment Protection Plan Revenue [Member]
Sales	$ 6,324	$ 5,788	$ 18,472	$ 16,990

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130543-203045

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130545-203045

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration