Commitments And Contingencies (Narrative) (Details) - USD ($) $ in Thousands	6 Months Ended
	Oct. 31, 2017	Oct. 31, 2016	Apr. 30, 2017
Commitments And Contingencies [Line Items]
Standard guarantee accrual amount	$ 3,600	$ 5,000	$ 6,800
Contingent business acquisition obligations	10,145		$ 10,428
Lines of credit, total obligation	42,700
Remaining franchise equity lines of credit-undrawn commitment	17,600
Loss Contingency Accrual [Roll Forward]
Balance, beginning of the period	2,300
Balance, end of the period	2,500	2,300
Scc [Member]
Loss Contingency Accrual [Roll Forward]
Balance, beginning of the period	4,500	65,265
Loss provisions	0	235
Payments	0	(40,000)
Balance, end of the period	$ 4,500	25,500
Level 3
Commitments And Contingencies [Line Items]
Contingent business acquisition obligations		$ 7,817