Goodwill And Intangible Assets (Schedule Of Intangible Assets) (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2017	Apr. 30, 2016
Goodwill and Intangible Assets [Line Items]
Document Fiscal Year Focus	2017
Gross Carrying Amount	$ 812,133	$ 762,984
Accumulated Amortization	(402,769)	(329,099)
Net	409,364	433,885
Reacquired franchise rights
Goodwill and Intangible Assets [Line Items]
Gross Carrying Amount	331,150	319,354
Accumulated Amortization	(90,877)	(68,284)
Net	240,273	251,070
Customer relationships
Goodwill and Intangible Assets [Line Items]
Gross Carrying Amount	234,603	206,607
Accumulated Amortization	(133,207)	(104,072)
Net	101,396	102,535
Computer Software, Intangible Asset [Member]
Goodwill and Intangible Assets [Line Items]
Gross Carrying Amount	139,709	131,161
Accumulated Amortization	(108,379)	(95,768)
Net	31,330	35,393
Noncompete agreements
Goodwill and Intangible Assets [Line Items]
Gross Carrying Amount	32,408	31,499
Accumulated Amortization	(27,559)	(25,572)
Net	4,849	5,927
Franchise agreements
Goodwill and Intangible Assets [Line Items]
Gross Carrying Amount	19,201	19,201
Accumulated Amortization	(10,774)	(9,494)
Net	8,427	9,707
Purchased technology
Goodwill and Intangible Assets [Line Items]
Gross Carrying Amount	54,700	54,700
Accumulated Amortization	(31,973)	(25,909)
Net	22,727	28,791
Trade Name
Goodwill and Intangible Assets [Line Items]
Gross Carrying Amount	362	462
Accumulated Amortization	0	0
Net	$ 362	$ 462