Financial Instruments - Schedule of Financial Instruments and Balance Sheet Classification (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Oct. 31, 2025	Oct. 31, 2024	Oct. 31, 2025	Oct. 31, 2024	Apr. 30, 2025
Fair Value Measurements, Nonrecurring Value Measurement [Abstract]
Assets, fair value	$ 1,037,615		$ 1,037,615		$ 1,277,869
Cash and cash equivalents	761,579		761,579		1,006,964
Balance Sheet Related Disclosures [Abstract]
Marketable Securities, Current	39,509		39,509		36,388
Marketable Securities, Non- current	237,227		237,227		233,626
Other Accrued Liabilities	(700)		(700)
Income Taxes & Other Receivables					891
Mutual funds
Balance Sheet Related Disclosures [Abstract]
Obligations for which assets are held in trust	217,700		217,700		205,300
Unvested obligations under deferred compensation plans	18,300		18,300		19,500
Increase in the fair value of marketable securities	6,700	$ 4,700	19,000	$ 18,900
Fair Value, Inputs, Level 2
Fair Value Measurements, Nonrecurring Value Measurement [Abstract]
Cost	41,516		41,516		40,086
Unrealized Gains	71		71		87
Unrealized Losses	(12)		(12)		(11)
Fair Value	41,575		41,575		40,162
Cash and cash equivalents	0		0		500
Balance Sheet Related Disclosures [Abstract]
Marketable Securities, Current	24,867		24,867		24,045
Marketable Securities, Non- current	16,708		16,708		15,617
Other Accrued Liabilities	0		0
Income Taxes & Other Receivables					0
Fair Value, Inputs, Level 2 | Foreign currency forward contracts
Fair Value Measurements, Nonrecurring Value Measurement [Abstract]
Foreign currency forward contracts	700		700		(891)
Cash and cash equivalents	0		0		0
Balance Sheet Related Disclosures [Abstract]
Marketable Securities, Current	0		0		0
Marketable Securities, Non- current	0		0		0
Other Accrued Liabilities	(700)		(700)
Income Taxes & Other Receivables					891
Fair Value, Inputs, Level 2 | Commercial paper
Fair Value Measurements, Nonrecurring Value Measurement [Abstract]
Cost	1,967		1,967		3,842
Unrealized Gains	0		0		0
Unrealized Losses	0		0		(1)
Fair Value	1,967		1,967		3,841
Cash and cash equivalents	0		0		500
Balance Sheet Related Disclosures [Abstract]
Marketable Securities, Current	1,967		1,967		3,341
Marketable Securities, Non- current	0		0		0
Other Accrued Liabilities	0		0
Income Taxes & Other Receivables					0
Fair Value, Inputs, Level 2 | Corporate notes/bonds
Fair Value Measurements, Nonrecurring Value Measurement [Abstract]
Cost	37,147		37,147		32,747
Unrealized Gains	68		68		83
Unrealized Losses	(11)		(11)		(10)
Fair Value	37,204		37,204		32,820
Cash and cash equivalents	0		0		0
Balance Sheet Related Disclosures [Abstract]
Marketable Securities, Current	22,900		22,900		18,709
Marketable Securities, Non- current	14,304		14,304		14,111
Other Accrued Liabilities	0		0
Income Taxes & Other Receivables					0
Fair Value, Inputs, Level 2 | U.S. Treasury and Agency Securities
Fair Value Measurements, Nonrecurring Value Measurement [Abstract]
Cost	2,402		2,402		3,497
Unrealized Gains	3		3		4
Unrealized Losses	(1)		(1)		0
Fair Value	2,404		2,404		3,501
Cash and cash equivalents	0		0		0
Balance Sheet Related Disclosures [Abstract]
Marketable Securities, Current	0		0		1,995
Marketable Securities, Non- current	2,404		2,404		1,506
Other Accrued Liabilities	0		0
Income Taxes & Other Receivables					0
Fair Value, Inputs, Level 1 | Mutual funds
Fair Value Measurements, Nonrecurring Value Measurement [Abstract]
Equity securities, fair value	235,161		235,161		230,352
Cash and cash equivalents	0		0		0
Balance Sheet Related Disclosures [Abstract]
Marketable Securities, Current	14,642		14,642		12,343
Marketable Securities, Non- current	220,519		220,519		218,009
Other Accrued Liabilities	0		0
Income Taxes & Other Receivables					0
Fair Value, Inputs, Level 1 | Equity investments
Fair Value Measurements, Nonrecurring Value Measurement [Abstract]
Equity securities, fair value	235,161		235,161		230,352
Cash and cash equivalents	0		0		0
Balance Sheet Related Disclosures [Abstract]
Marketable Securities, Current	14,642		14,642		12,343
Marketable Securities, Non- current	220,519		220,519		218,009
Other Accrued Liabilities	0		0
Income Taxes & Other Receivables					0
Fair Value, Inputs, Level 1 | Cash
Fair Value Measurements, Nonrecurring Value Measurement [Abstract]
Cash and cash equivalents, fair value	598,067		598,067		704,091
Cash and cash equivalents	598,067		598,067		704,091
Balance Sheet Related Disclosures [Abstract]
Marketable Securities, Current	0		0		0
Marketable Securities, Non- current	0		0		0
Other Accrued Liabilities	0		0
Income Taxes & Other Receivables					0
Fair Value, Inputs, Level 1 | Money market funds
Fair Value Measurements, Nonrecurring Value Measurement [Abstract]
Cash and cash equivalents, fair value	163,512		163,512		302,373
Cash and cash equivalents	163,512		163,512		302,373
Balance Sheet Related Disclosures [Abstract]
Marketable Securities, Current	0		0		0
Marketable Securities, Non- current	0		0		0
Other Accrued Liabilities	$ 0		$ 0
Income Taxes & Other Receivables					$ 0