Goodwill And Intangible Assets (Narrative) (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Jan. 31, 2019 USD ($)	Jan. 31, 2018 USD ($)	Jan. 31, 2019 USD ($) office	Jan. 31, 2018 USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
Payments to acquire franchisee and competitor businesses			$ (42,428)	$ (39,397)
Number of offices acquired | office			175
Amortization	$ 18,700	$ 20,800	$ 54,500	$ 59,500
Estimated amortization, 2019	73,200		73,200
Estimated amortization, 2020	60,700		60,700
Estimated amortization, 2021	44,200		44,200
Estimated amortization, 2022	31,400		31,400
Estimated amortization, 2023	$ 18,200		$ 18,200