Commitments And Contingencies (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended
	Jul. 31, 2016	Jul. 31, 2015	Apr. 30, 2016	Apr. 30, 2015
Commitments And Contingencies [Line Items]
Standard guarantee accrual amount	$ 5,800	$ 7,600	$ 7,000
Contingent business acquisition obligations	8,347		8,657
Lines of credit, total obligation	59,400
Remaining franchise equity lines of credit-undrawn commitment	28,100
Amounts deferred for new extended service plans issued	978	983
Deferred Revenue, Revenue Recognized	(31,650)	(31,069)
Deferred Revenue	$ 173,670	159,693	$ 204,342	$ 189,779
Level 3
Commitments And Contingencies [Line Items]
Contingent business acquisition obligations		$ 10,650