Note L - Correction of An Immaterial Error In Previously Issued Financial Statements - Correction of An Immaterial Error In Previously Issued Financial Statements (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended
	Jan. 31, 2023	Oct. 31, 2022	Jul. 31, 2022	Jan. 31, 2022	Oct. 31, 2021	Jul. 31, 2021	Jan. 31, 2023	Jan. 31, 2022	Dec. 31, 2022	Apr. 30, 2022	Dec. 31, 2021	Apr. 30, 2021
Finance receivables, net	$ 1,023,181			$ 806,989			$ 1,023,181	$ 806,989	$ 1,023,181	$ 863,674	$ 863,674	$ 632,270
Deferred income tax liabilities, net									37,333	30,449	30,449
Retained earnings									$ 683,724	665,410	$ 665,410
Sales	275,467			248,312			873,499	739,734
Provision for credit losses	85,650			61,646			250,719	167,987
Provision for income taxes	251			6,143			5,197	20,046
Net income	1,508	$ 3,139	$ 13,697	19,140	$ 23,425	$ 26,054	18,344	68,618
Net income attributable to common shareholders	$ 1,498			$ 19,130			$ 18,314	$ 68,588
Basic (in dollars per share)	$ 0.24			$ 2.95			$ 2.87	$ 10.49
Diluted (in dollars per share)	$ 0.23			$ 2.82			$ 2.79	$ 9.97
Previously Reported [Member]
Finance receivables, net										854,290
Deferred income tax liabilities, net										28,233
Retained earnings										658,242
Sales				$ 252,918				$ 750,942
Provision for credit losses				66,741				181,796
Provision for income taxes				6,024				19,433
Net income				18,770				66,630
Net income attributable to common shareholders				$ 18,760				$ 66,600
Basic (in dollars per share)				$ 2.89				$ 10.18
Diluted (in dollars per share)				$ 2.77				$ 9.68
Revision of Prior Period, Adjustment [Member]
Finance receivables, net										9,384
Deferred income tax liabilities, net										2,216
Retained earnings										$ 7,168
Sales				$ (4,606)				$ (11,208)
Provision for credit losses				(5,095)				(13,809)
Provision for income taxes				119				613
Net income				370				1,988
Net income attributable to common shareholders				$ 370				$ 1,988
Basic (in dollars per share)				$ 0.06				$ 0.31
Diluted (in dollars per share)				$ 0.05				$ 0.29