Pensions and Other Postretirement Benefits (Details 2) - USD ($) $ in Millions	12 Months Ended
	Apr. 30, 2025	Apr. 30, 2024	Apr. 30, 2023
Defined Benefit Pension Plans | United States [Member]
Weighted-average assumptions used in determining net periodic benefit costs:
Discount rate used to determine benefit obligation	5.43%	5.19%	4.59%
Discount rate used to determine service cost	6.06%	5.38%	4.77%
Discount rate used to determine interest cost	5.38%	5.08%	4.26%
Expected return on plan assets	4.70%	5.35%	4.51%
Rate of compensation increase	3.00%	3.66%	3.55%
Defined Benefit Pension Plans | CANADA
Weighted-average assumptions used in determining net periodic benefit costs:
Discount rate used to determine benefit obligation	5.07%	4.59%	2.41%
Discount rate used to determine service cost	0.00%	0.00%	0.00%
Discount rate used to determine interest cost	5.04%	4.65%	2.33%
Expected return on plan assets	0.00%	3.30%	1.60%
Defined Benefit Plan, Gain (Loss) Due to Settlement, 2021 Canada Buy-Out Contract	$ 0.0	$ 3.2
Other Postretirement Benefits Plan | United States [Member]
Weighted-average assumptions used in determining net periodic benefit costs:
Discount rate used to determine benefit obligation	5.86%	5.15%	4.52%
Discount rate used to determine service cost	5.92%	5.23%	4.64%
Discount rate used to determine interest cost	5.77%	5.06%	4.11%
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	5.12%	4.62%	4.50%
Discount rate used to determine service cost	5.21%	4.73%	4.69%
Discount rate used to determine interest cost	5.07%	4.65%	4.18%
Expected return on plan assets	0.00%	0.00%	0.00%