Note B - Summary of Significant Accounting Policies (Details Textual) - USD ($)				3 Months Ended			6 Months Ended	9 Months Ended	12 Months Ended			15 Months Ended
	Oct. 25, 2017	May 31, 2016	May 30, 2016	Jul. 31, 2018	Jan. 31, 2018	Jul. 31, 2017	Oct. 24, 2017	Jul. 31, 2018	Apr. 30, 2019	Apr. 30, 2018	Apr. 30, 2017	Jul. 31, 2018
Number of Reportable Segments				1
Financing Receivable Interest Rate				16.30%
Interest Earned on Financing Receivables				$ 2,300,000						$ 2,200,000
Finance Receivables, Customer Payments Due Either Weekly or Bi-Weekly, Percentage				75.00%
Financing Receivable, Greater Than or Equal to 30 Days Past Due, Percent of Portfolio				3.50%		4.60%		3.50%				3.50%
Financing Receivable, Average Days Past Due At Charge Off				62 days
Financing Receivable, Weighted Average Total Contract Term				2 years 252 days
Financing Receivable, Remaining Contract Term				1 year 345 days
Financing Receivable, Allowance for Credit Losses, Ending Balance				$ 122,447,000		$ 113,733,000		$ 122,447,000		117,821,000	$ 109,693,000	$ 122,447,000
Finance Receivables, Allowance, Percent of Principle Balance				25.00%				25.00%				25.00%
Finance Receivable Principal Balance				$ 520,820,000		$ 483,719,000		$ 520,820,000		501,438,000		$ 520,820,000
Percent of Chargeoffs in the First 10 to 11 Months of a Contract				50.00%				50.00%				50.00%
Average Age of Account at Charge-Off Date				1 year
Payment Protection Plan Liability, Anticipated Losses in Excess of Deferred Revenues				$ 0				$ 0		0		$ 0
Goodwill, Impairment Loss				$ 0						0
Effective Income Tax Rate Reconciliation, Percent, Total				17.10%		35.80%
Tax Adjustments, Settlements, and Unusual Provisions				$ (943,000)	$ (8,100,000)	$ (172,000)
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent				30.40%							35.00%
Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability					$ (8,100,000)
Income Tax Examination, Penalties and Interest Accrued, Total				$ 0				0		0		0
Financing Receivable, Recorded Investment Greater Than 90 Days Past Due				1,554,000		2,028,000		1,554,000		1,604,000		1,554,000
Late Fee Income Generated by Servicing Financial Assets, Amount				$ 446,000		$ 449,000
Stock Repurchased During Period, Shares				115,999		102,843
Stock Repurchased During Period, Value				$ 7,400,000		$ 3,700,000
Treasury Stock, Shares to Establish Reserve Account to Secure Service Contracts				10,000
Scenario, Forecast [Member]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent									21.00%
Payment Protection Plan [Member]
Deferred Revenue				$ 20,429,000				20,429,000		19,823,000		20,429,000
Service Contract [Member]
Deferred Revenue				$ 10,605,000				10,605,000		$ 10,332,000		$ 10,605,000
Maximum [Member]
Financing Receivable Interest Rate		16.50%	15.00%	16.50%
Allowance for Credit Losses, Primary Factor Units Repossessed or Charged Off Evaluation Period				5 years
Minimum [Member]
Financing Receivable Interest Rate				15.00%
Allowance for Credit Losses, Primary Factor Units Repossessed or Charged Off Evaluation Period				1 year
Revolving Credit Facility [Member]
Line of Credit Facility, Distribution Limitations, Maximum Aggregate Amount of Stock Repurchases							$ 40,000,000	$ 50,000,000
Line of Credit Facility, Distribution Limitations Percentage of Sum of Borrowing Bases	20.00%						25.00%					20.00%
Line of Credit Facility, Distribution Limitations Percentage of Consolidated Net Income												75.00%
Line of Credit Facility Distribution Limitations Minimum Percentage of Aggregate Funds Available												12.50%
Customer Concentration Risk [Member] | Sales Revenue, Net [Member] | Arkansas, USA [Member]
Concentration Risk, Percentage				29.00%