Goodwill And Intangible Assets (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jan. 31, 2018	Jan. 31, 2017	Jan. 31, 2018	Jan. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Payments to acquire franchisee and competitor businesses			$ 39,397	$ 52,825
Amortization	$ 20,800	$ 19,300	59,500	$ 57,300
Estimated amortization, 2018	79,200		79,200
Estimated amortization, 2019	67,300		67,300
Estimated amortization, 2020	50,600		50,600
Estimated amortization, 2021	35,600		35,600
Estimated amortization, 2022	$ 24,300		$ 24,300