GOODWILL AND INTANGIBLE ASSETS (Schedule of Intangible Assets) (Details) - USD ($) $ in Thousands	Jan. 31, 2020	Apr. 30, 2019	Jan. 31, 2019
Goodwill and Intangible Assets [Line Items]
Gross Carrying Amount	$ 1,023,821	$ 872,195	$ 880,450
Accumulated Amortization	(590,747)	(529,702)	(523,498)
Net	433,074	342,493	356,952
Reacquired franchise rights
Goodwill and Intangible Assets [Line Items]
Gross Carrying Amount	364,376	350,410	350,459
Accumulated Amortization	(153,392)	(136,345)	(130,618)
Net	210,984	214,065	219,841
Customer relationships
Goodwill and Intangible Assets [Line Items]
Gross Carrying Amount	313,521	274,838	274,293
Accumulated Amortization	(219,664)	(195,174)	(187,080)
Net	93,857	79,664	87,213
Internally-developed software
Goodwill and Intangible Assets [Line Items]
Gross Carrying Amount	154,962	139,239	147,465
Accumulated Amortization	(116,383)	(109,885)	(119,664)
Net	38,579	29,354	27,801
Noncompete agreements
Goodwill and Intangible Assets [Line Items]
Gross Carrying Amount	41,386	33,376	33,369
Accumulated Amortization	(33,151)	(31,446)	(31,040)
Net	8,235	1,930	2,329
Franchise agreements
Goodwill and Intangible Assets [Line Items]
Gross Carrying Amount	19,201	19,201	19,201
Accumulated Amortization	(14,294)	(13,334)	(13,014)
Net	4,907	5,867	6,187
Purchased technology
Goodwill and Intangible Assets [Line Items]
Gross Carrying Amount	122,801	54,700	54,700
Accumulated Amortization	(53,525)	(43,518)	(42,082)
Net	69,276	11,182	12,618
Trade name
Goodwill and Intangible Assets [Line Items]
Gross Carrying Amount	5,800
Accumulated Amortization	(338)
Net	5,462
Acquired assets pending final allocation
Goodwill and Intangible Assets [Line Items]
Gross Carrying Amount	1,774	431	963
Accumulated Amortization	0	0	0
Net	$ 1,774	$ 431	$ 963