Fair Value of Financial Instruments and Long Term Debt - Carrying Value of Long-term Debt (Details) $ in Thousands	12 Months Ended
Apr. 30, 2024 USD ($) installment_payment	Apr. 30, 2023 USD ($) installment_payment
Debt Instrument
Finance lease liabilities (Note 7)	$ 101,818	$ 95,072
Long-term debt	1,535,500
Debt issuance costs	(1,379)	(1,698)
Total	1,635,939	1,673,374
Less current maturities	53,181	52,861
Long-term debt and finance lease obligations, net of current maturities	$ 1,582,758	$ 1,620,513
Senior Notes \| 3.67% Senior Notes (Series A) due in 7 installments beginning June 17, 2022, and ending June 15, 2028
Debt Instrument
Interest rate	3.67%	3.67%
Number of payments \| installment_payment	7	7
Long-term debt	$ 111,000	$ 135,000
Senior Notes \| 3.75% Senior Notes (Series B) due in 7 installments beginning December 17, 2022 and ending December 18, 2028
Debt Instrument
Interest rate	3.75%	3.75%
Number of payments \| installment_payment	7	7
Long-term debt	$ 37,000	$ 45,000
Senior Notes \| 3.65% Senior Notes (Series C) due in 7 installments beginning May 2, 2025 and ending May 2, 2031
Debt Instrument
Interest rate	3.65%	3.65%
Number of payments \| installment_payment	7	7
Long-term debt	$ 50,000	$ 50,000
Senior Notes \| 3.72% Senior Notes (Series D) due in 7 installments beginning October 28, 2025 and ending October 28, 2031
Debt Instrument
Interest rate	3.72%	3.72%
Number of payments \| installment_payment	7	7
Long-term debt	$ 50,000	$ 50,000
Senior Notes \| 3.51% Senior Notes (Series E) due June 13, 2025
Debt Instrument
Interest rate	3.51%
Long-term debt	$ 150,000	150,000
Senior Notes \| 3.77% Senior Notes (Series F) due August 22, 2028
Debt Instrument
Interest rate	3.77%
Long-term debt	$ 250,000	250,000
Senior Notes \| 2.85% Senior Notes (Series G) due August 7, 2030
Debt Instrument
Interest rate	2.85%
Long-term debt	$ 325,000	325,000
Senior Notes \| 2.96% Senior Notes (Series H) due August 6, 2032
Debt Instrument
Interest rate	2.96%
Long-term debt	$ 325,000	325,000
Line of Credit \| Term Loan Facility
Debt Instrument
Long-term debt	$ 237,500	$ 250,000

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