Goodwill And Intangible Assets (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Oct. 31, 2017	Oct. 31, 2016	Oct. 31, 2017	Oct. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Payments to Acquire Businesses, Net of Cash Acquired			$ 27,522	$ 36,151
Amortization	$ 19,400	$ 20,100	38,700	$ 38,000
Estimated amortization, 2018	76,000		76,000
Estimated amortization, 2019	61,100		61,100
Estimated amortization, 2020	44,800		44,800
Estimated amortization, 2021	30,500		30,500
Estimated amortization, 2022	$ 20,200		$ 20,200