Debt and Available Credit Facilities (Details) - USD ($) $ in Thousands		3 Months Ended
		Jul. 31, 2021	Jul. 31, 2020	Apr. 30, 2021	May 30, 2019
Components of Total Debt Outstanding [Abstract]
Short-term portion of long-term debt	[1]	$ 12,500		$ 12,500
Total long-term debt, less current portion		952,020		809,088
Total debt		964,520		821,588
Unamortized issuance costs		$ 500		500
Amended and Restated RCA [Member]
Debt and Available Credit Facilities [Abstract]
Term of credit facility		5 years
Amortization expense of the lender and non-lender fees in interest expense		$ 300	$ 300
Term Loan A Facility [Member]
Debt and Available Credit Facilities [Abstract]
Term of credit facility		5 years
Term Loan A Facility [Member] | Amended and Restated RCA [Member]
Components of Total Debt Outstanding [Abstract]
Total long-term debt, less current portion	[2]	$ 219,844		222,928
Debt and Available Credit Facilities [Abstract]
Credit agreement face amount					$ 250,000
Revolving Credit Facility [Member]
Debt and Available Credit Facilities [Abstract]
Term of credit facility		5 years
Revolving Credit Facility [Member] | Amended and Restated RCA [Member]
Components of Total Debt Outstanding [Abstract]
Total long-term debt, less current portion		$ 732,176		$ 586,160
Debt and Available Credit Facilities [Abstract]
Amount of financing available under credit facilities					$ 1,250,000
Syndicate Bank Group led by Bank of America [Member] | Revolving Credit Facility [Member] | Amended and Restated RCA [Member]
Debt and Available Credit Facilities [Abstract]
Optional credit limit increase available on request		500,000
Minimum increments in which optional credit limit increase may be requested		50,000
Unused borrowing capacity under our Amended and Restated RCA and other facilities		$ 518,800
Syndicate Bank Group led by Bank of America [Member] | Revolving Credit Facility [Member] | Amended and Restated RCA [Member] | Minimum [Member]
Debt and Available Credit Facilities [Abstract]
Line of credit facility fee percentage		0.15%
Syndicate Bank Group led by Bank of America [Member] | Revolving Credit Facility [Member] | Amended and Restated RCA [Member] | Maximum [Member]
Debt and Available Credit Facilities [Abstract]
Line of credit facility fee percentage		0.25%
Syndicate Bank Group led by Bank of America [Member] | Revolving Credit Facility [Member] | Amended and Restated RCA [Member] | LIBOR [Member] | Minimum [Member]
Debt and Available Credit Facilities [Abstract]
Applicable margin		0.98%
Syndicate Bank Group led by Bank of America [Member] | Revolving Credit Facility [Member] | Amended and Restated RCA [Member] | LIBOR [Member] | Maximum [Member]
Debt and Available Credit Facilities [Abstract]
Applicable margin		1.50%
Syndicate Bank Group led by Bank of America [Member] | Revolving Credit Facility [Member] | Amended and Restated RCA [Member] | Base Rate [Member] | Minimum [Member]
Debt and Available Credit Facilities [Abstract]
Applicable margin		0.00%
Syndicate Bank Group led by Bank of America [Member] | Revolving Credit Facility [Member] | Amended and Restated RCA [Member] | Base Rate [Member] | Maximum [Member]
Debt and Available Credit Facilities [Abstract]
Applicable margin		0.50%
Syndicate Bank Group led by Bank of America [Member] | Revolving Credit Facility [Member] | Amended and Restated RCA [Member] | Federal Funds Effective Rate [Member]
Debt and Available Credit Facilities [Abstract]
Margin rate over reference rate used in determining base rate		0.50%
Syndicate Bank Group led by Bank of America [Member] | Revolving Credit Facility [Member] | Amended and Restated RCA [Member] | Eurocurrency Rate [Member]
Debt and Available Credit Facilities [Abstract]
Margin rate over reference rate used in determining base rate		1.00%

[1] Relates to our term loan A under the Amended and Restated RCA.

[2] Amounts are shown net of unamortized issuance costs of $0.5 million as of July 31, 2021 and $0.5 million as of April 30, 2021.