Financial Instruments - Financial Instruments and Balance Sheet Classification (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Oct. 31, 2024	Oct. 31, 2023	Oct. 31, 2024	Oct. 31, 2023	Apr. 30, 2024
Fair Value Measurements, Nonrecurring Value Measurement [Abstract]
Assets, fair value	$ 966,457		$ 966,457		$ 1,195,001
Balance Sheet Related Disclosures [Abstract]
Cash and Cash Equivalents	694,850		694,850		941,005
Marketable Securities, Current	40,658		40,658		42,742
Marketable Securities, Non- current	231,956		231,956		211,681
Other Accrued Liabilities	(1,007)		(1,007)		(427)
Mutual funds
Balance Sheet Related Disclosures [Abstract]
Obligations for which assets are held in trust	215,400		215,400		198,600
Unvested obligations under deferred compensation plans	19,600		19,600		22,400
Increase (decrease) in the fair value of marketable securities	4,700	$ (13,800)	18,900	$ (1,000)
Fair Value, Inputs, Level 2
Fair Value Measurements, Nonrecurring Value Measurement [Abstract]
Cost	39,690		39,690		38,550
Unrealized Gains	108		108		4
Unrealized Losses	(32)		(32)		(55)
Debt securities AFS, fair value	39,766		39,766		38,499
Balance Sheet Related Disclosures [Abstract]
Cash and Cash Equivalents	0		0		3,932
Marketable Securities, Current	26,109		26,109		25,414
Marketable Securities, Non- current	13,657		13,657		9,153
Other Accrued Liabilities	0		0		0
Fair Value, Inputs, Level 2 | Foreign currency forward contracts
Fair Value Measurements, Nonrecurring Value Measurement [Abstract]
Foreign currency forward contracts, fair value	(1,007)		(1,007)		(427)
Balance Sheet Related Disclosures [Abstract]
Cash and Cash Equivalents	0		0		0
Marketable Securities, Current	0		0		0
Marketable Securities, Non- current	0		0		0
Other Accrued Liabilities	(1,007)		(1,007)		(427)
Fair Value, Inputs, Level 2 | Commercial paper
Fair Value Measurements, Nonrecurring Value Measurement [Abstract]
Cost	5,645		5,645		16,873
Unrealized Gains	1		1		1
Unrealized Losses	(4)		(4)		(19)
Debt securities AFS, fair value	5,642		5,642		16,855
Balance Sheet Related Disclosures [Abstract]
Cash and Cash Equivalents	0		0		3,932
Marketable Securities, Current	5,642		5,642		12,923
Marketable Securities, Non- current	0		0		0
Other Accrued Liabilities	0		0		0
Fair Value, Inputs, Level 2 | Corporate notes/bonds
Fair Value Measurements, Nonrecurring Value Measurement [Abstract]
Cost	27,879		27,879		17,322
Unrealized Gains	92		92		3
Unrealized Losses	(28)		(28)		(27)
Debt securities AFS, fair value	27,943		27,943		17,298
Balance Sheet Related Disclosures [Abstract]
Cash and Cash Equivalents	0		0		0
Marketable Securities, Current	15,536		15,536		10,050
Marketable Securities, Non- current	12,407		12,407		7,248
Other Accrued Liabilities	0		0		0
Fair Value, Inputs, Level 2 | U.S. Treasury and Agency Securities
Fair Value Measurements, Nonrecurring Value Measurement [Abstract]
Cost	6,166		6,166		4,355
Unrealized Gains	15		15		0
Unrealized Losses	0		0		(9)
Debt securities AFS, fair value	6,181		6,181		4,346
Balance Sheet Related Disclosures [Abstract]
Cash and Cash Equivalents	0		0		0
Marketable Securities, Current	4,931		4,931		2,441
Marketable Securities, Non- current	1,250		1,250		1,905
Other Accrued Liabilities	0		0		0
Fair Value, Inputs, Level 1 | Mutual funds
Fair Value Measurements, Nonrecurring Value Measurement [Abstract]
Equity securities, fair value	232,848		232,848		219,856
Balance Sheet Related Disclosures [Abstract]
Cash and Cash Equivalents	0		0		0
Marketable Securities, Current	14,549		14,549		17,328
Marketable Securities, Non- current	218,299		218,299		202,528
Other Accrued Liabilities	0		0		0
Fair Value, Inputs, Level 1 | Equity investments
Fair Value Measurements, Nonrecurring Value Measurement [Abstract]
Equity securities, fair value	232,848		232,848		219,856
Balance Sheet Related Disclosures [Abstract]
Cash and Cash Equivalents	0		0		0
Marketable Securities, Current	14,549		14,549		17,328
Marketable Securities, Non- current	218,299		218,299		202,528
Other Accrued Liabilities	0		0		0
Fair Value, Inputs, Level 1 | Cash
Fair Value Measurements, Nonrecurring Value Measurement [Abstract]
Cash and cash equivalents, fair value	519,083		519,083		790,938
Balance Sheet Related Disclosures [Abstract]
Cash and Cash Equivalents	519,083		519,083		790,938
Marketable Securities, Current	0		0		0
Marketable Securities, Non- current	0		0		0
Other Accrued Liabilities	0		0		0
Fair Value, Inputs, Level 1 | Money market funds
Fair Value Measurements, Nonrecurring Value Measurement [Abstract]
Cash and cash equivalents, fair value	175,767		175,767		146,135
Balance Sheet Related Disclosures [Abstract]
Cash and Cash Equivalents	175,767		175,767		146,135
Marketable Securities, Current	0		0		0
Marketable Securities, Non- current	0		0		0
Other Accrued Liabilities	$ 0		$ 0		$ 0