Pensions and Other Postretirement Benefits (Details 2) - USD ($) $ in Millions	12 Months Ended
	Apr. 30, 2024	Apr. 30, 2023	Apr. 30, 2022
Defined Benefit Pension Plans | United States [Member]
Weighted-average assumptions used in determining net periodic benefit costs:
Discount rate used to determine benefit obligation	5.19%	4.59%	3.13%
Discount rate used to determine service cost	5.38%	4.77%	3.53%
Discount rate used to determine interest cost	5.08%	4.26%	2.40%
Expected return on plan assets	5.35%	4.51%	4.59%
Rate of compensation increase	3.66%	3.55%	3.55%
Defined Benefit Pension Plans | CANADA
Weighted-average assumptions used in determining net periodic benefit costs:
Discount rate used to determine benefit obligation	4.59%	2.41%	2.15%
Discount rate used to determine service cost	0.00%	0.00%	0.00%
Discount rate used to determine interest cost	4.65%	2.33%	1.95%
Expected return on plan assets	3.30%	1.60%	1.70%
Defined Benefit Plan, Gain (Loss) Due to Settlement, 2021 Canada Buy-Out Contract	$ 3.2	$ 0.0	$ 0.0
Other Postretirement Benefits Plan | United States [Member]
Weighted-average assumptions used in determining net periodic benefit costs:
Discount rate used to determine benefit obligation	5.15%	4.52%	2.97%
Discount rate used to determine service cost	5.23%	4.64%	3.20%
Discount rate used to determine interest cost	5.06%	4.11%	2.07%
Expected return on plan assets	0.00%	0.00%	0.00%
Rate of compensation increase	0.00%	0.00%	0.00%
Other Postretirement Benefits Plan | CANADA
Weighted-average assumptions used in determining net periodic benefit costs:
Discount rate used to determine benefit obligation	4.62%	4.50%	3.03%
Discount rate used to determine service cost	4.73%	4.69%	3.52%
Discount rate used to determine interest cost	4.65%	4.18%	2.32%
Expected return on plan assets	0.00%	0.00%	0.00%