Note B - Summary of Significant Accounting Policies (Detail) (USD $)	9 Months Ended		12 Months Ended
	Jan. 31, 2013	Jan. 31, 2012	Apr. 30, 2012
Number of Reportable Segments	1
Concentration Risk, Percentage	39.00%
Line of Credit Facility, Dividend Restrictions	The distribution limitations under the Credit Facilities allow the Company to repurchase the Company's stock so long as: either (a) the aggregate amount of such repurchases does not exceed $40 million and the sum of borrowing bases combined minus the principal balances of all revolver loans after giving effect to such repurchases is equal to or greater than 25% of the sum of the borrowing bases, or (b) the aggregate amount of such repurchases does not exceed 75% of the consolidated net income of the Company measured on a trailing twelve month basis; provided that immediately before and after giving effect to the stock repurchases, at least 12.5% of the aggregate funds committed under the credit facilities remain available.
Finance Receivables Interest Rate Range Start	11.00%
Finance Receivable Interest Rate Range End	19.00%
Interest Earned On Financing Receivables (in Dollars)	$ 1,900,000		$ 1,400,000
Finance Receivables, Customer Payments Due Either Weekly or Bi-Weekly, Percentage	80.00%
Financing Receivable, Greater Than Or Equal To 30 Days Past Due, Percent Of Portfolio	6.00%	4.70%
Financing Receivable, Average Days Past Due At Charge Off	63
Financing Receivable, Allowance for Credit Losses, Policy for Uncollectible Amounts	The calculation of the allowance for credit losses uses the following primary factors: The number of units repossessed or charged-off as a percentage of total units financed over specific historical periods of time. The average net repossession and charge-off loss per unit during the last eighteen months, segregated by the number of months since the contract origination date, and adjusted for the expected future average net charge-off loss per unit.About 50% of the charge-offs that will ultimately occur in the portfolio are expected to occur within 10-11 months following the loan origination date.The average age of an account at charge-off date is 10.6 months. The timing of repossession and charge-off losses relative to the date of sale (i.e., how long it takes for a repossession or charge-off to occur) for repossessions and charge-offs occurring during the last eighteen months. A point estimate is produced by this analysis which is then supplemented by any positive or negative subjective factors to arrive at an overall reserve amount that management considers to be a reasonable estimate of incurred losses that will be realized via actual charge-offs in the future.Periods of economic downturn do not necessarily lead to increased credit losses because the Company provides basic affordable transportation to customers that, for the most part, do not have access to public transportation.The effectiveness of the execution of internal policies and procedures within the collections area has historically had a more significant effect on collection results than macro-economic issues. The Company offers retail customers in most states the option of purchasing a payment protection plan product as an add-on to the installment sale contract.This product contractually obligates the Company to cancel the remaining principal outstanding for any contract where the retail customer has totaled the vehicle, as defined, or the vehicle has been stolen.The Company periodically evaluates anticipated losses to ensure that if anticipated losses exceed deferred payment protection plan revenues, an additional liability is recorded for such difference.No such liability was required at January 31, 2013 or April 30, 2012.
Average Age of Account At Charge-Off Date	10 months 18 days
Service Contract Revenue Recognition Period	5 months
Late Fee Income Generated by Servicing Financial Assets, Amount (in Dollars)	1,400,000	1,200,000
Financing Receivable Recorded Investment Greater Than 90 Days Past Due (in Dollars)	2,401,000	978,000	656,000
Stock Repurchased During Period, Shares (in Shares)	397,314	1,002,363
Stock Repurchased During Period, Value (in Dollars)	$ 17,200,000	$ 29,900,000
Summary Of Significant Accounting Policies Note [Member]
Line of Credit Facility, Dividend Restrictions	Restrictions on Distributions/Dividends The Company's revolving credit facilities generally limit distributions by the Company to its shareholders in order to repurchase the Company's common stock.The distribution limitations under the Agreement allow the Company to repurchase the Company's stock so long as: either (a) the aggregate amount of such repurchases does not exceed $40 million and the sum of borrowing bases combined minus the principal balances of all revolver loans after giving effect to such repurchases is equal to or greater than 25% of the sum of the borrowing bases, or (b) the aggregate amount of such repurchases does not exceed 75% of the consolidated net income of the Company measured on a trailing twelve month basis; provided that immediately before and after giving effect to the stock repurchases, at least 12.5% of the aggregate funds committed under the credit facilities remain available. Thus, the Company is limited in the amount of dividends or other distributions it can make to its shareholders without the consent of the Company's lenders.
Furniture, fixtures, and equipment [Member] | Minimum [Member]
Property, Plant and Equipment, Useful Life	3 years
Furniture, fixtures, and equipment [Member] | Maximum [Member]
Property, Plant and Equipment, Useful Life	7 years
Leasehold Improvements [Member] | Minimum [Member]
Property, Plant and Equipment, Useful Life	5 years
Leasehold Improvements [Member] | Maximum [Member]
Property, Plant and Equipment, Useful Life	15 years
Building and Building Improvements [Member] | Minimum [Member]
Property, Plant and Equipment, Useful Life	18 years
Building and Building Improvements [Member] | Maximum [Member]
Property, Plant and Equipment, Useful Life	39 years