Commitments And Contingencies (Narrative) (Details) - USD ($)	12 Months Ended			108 Months Ended
	Apr. 30, 2017	Apr. 30, 2016	Apr. 30, 2015	Apr. 30, 2017
Commitments And Contingencies [Line Items]
Additional tax assessment limit per client	$ 6,000			$ 6,000
Standard guarantee accrual amount	$ 6,800,000	$ 7,000,000		6,800,000
Document Fiscal Year Focus	2017
Other Commitment, Percentage of Participation Interest Required to be Purchased at Par	90.00%
Commitments to Extend Credit, Total	$ 53,000,000			53,000,000
Contingent acquisition liabilities, Carrying Amount	10,428,000	8,657,000		10,428,000
Remaining franchise equity lines of credit-undrawn commitment	26,000,000			26,000,000
Amounts deferred for new extended service plans issued		119,915,000
Revenue recognized on previous deferrals		(105,352,000)
Deferred revenue		204,342,000	$ 189,779,000
Obligation under deferred compensation plans	25,200,000	29,000,000		25,200,000
Rent expense	$ 236,200,000	228,500,000	$ 213,100,000
Claims received for loans				2,600,000,000
Minimum
Commitments And Contingencies [Line Items]
Term of operating leases, years	3 years
Maximum
Commitments And Contingencies [Line Items]
Term of operating leases, years	5 years
Refund Advance [Member]
Commitments And Contingencies [Line Items]
Loss Contingency Accrual	$ 700,000			700,000
Loss Contingency, Estimate of Possible Loss	73,000,000			73,000,000
Peace of Mind
Commitments And Contingencies [Line Items]
Amounts deferred for new extended service plans issued	120,691,000
Revenue recognized on previous deferrals	(113,810,000)
Deferred revenue	$ 211,223,000	$ 204,342,000		$ 211,223,000