Stock-Based Compensation PBRSUs (Details) - Performance Based Restricted Stock Units (PBRSUs) [Member] - $ / shares shares in Thousands	12 Months Ended
	Apr. 30, 2022	Apr. 30, 2021	Apr. 30, 2020
Number of PBRSUs [Roll Forward]
Outstanding, beginning balance (shares)	254
PBRSUs granted (shares)	108
PBRSUs adjusted for performance and dividends	(10)
PBRSUs converted to common shares (shares)	(77)
PBRSUs forfeited (shares)	(5)
Outstanding, ending balance (shares)	270	254
Weighted Average Fair Value at Grant Date [Roll Forward]
Weighted Average Fair Value at Grant Date, Outstanding, Beginning (dollars per share)	$ 61.76
Weighted Average Fair Value at Grant Date, Granted (dollars per share)	70.11	$ 73.68	$ 56.99
Weighted Average Fair Value at Grant Date, Adjusted for Performance and Dividends (dollars per share)	55.28
Weighted Average Fair Value at Grant Date, Converted to Common Shares (dollars per share)	55.28
Weighted Average Fair Value at Grant Date, Forfeited (dollars per share)	69.19
Weighted Average Fair Value at Grant Date, Outstanding, Ending (dollars per share)	$ 67.02	$ 61.76