Goodwill And Intangible Assets (Schedule of Weighted-average Lives of Assets Acquired) (Details) $ in Thousands	9 Months Ended
	Jan. 31, 2019 USD ($)
Acquired Finite-Lived Intangible Assets [Line Items]
Amount	$ 28,742
Weighted-Average Life (in years)	5 years
Franchise agreements
Acquired Finite-Lived Intangible Assets [Line Items]
Amount	$ 10,734
Weighted-Average Life (in years)	5 years
Customer relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Amount	$ 17,520
Weighted-Average Life (in years)	5 years
Noncompete agreements
Acquired Finite-Lived Intangible Assets [Line Items]
Amount	$ 488
Weighted-Average Life (in years)	5 years