Income Taxes - Components of Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Apr. 30, 2021	Apr. 30, 2020
Income Tax Disclosure [Abstract]
Deferred compensation	$ 107,834	$ 86,479
Operating lease liability	34,183	37,934
Loss carryforwards	39,704	27,845
Reserves and accruals	16,393	14,211
Allowance for doubtful accounts	4,885	4,029
Other		2,703
Gross deferred tax assets	202,999	173,201
Operating lease, right-of-use, assets	(27,777)	(29,998)
Intangibles and Goodwill	(26,570)	(29,006)
Property and equipment	(20,590)	(22,332)
Prepaid expenses	(23,928)	(19,567)
Marketable Securities	(7,003)
Other	(2,684)
Gross deferred tax liabilities	(108,552)	(100,903)
Valuation allowances	(25,173)	(17,875)
Net deferred tax asset	$ 69,274	$ 54,423

Deferred tax assets operating lease liability.

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Deferred tax liabilities, operating lease, right-of-use assets.

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Amount of deferred tax liability attributable to taxable temporary differences.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards.

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Amount, after allocation of valuation allowances and deferred tax liability, of deferred tax asset attributable to deductible differences and carryforwards, without jurisdictional netting.

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Amount, before allocation of valuation allowance, of deferred tax asset attributable to deductible temporary differences, classified as other.

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Amount, before allocation of valuation allowance, of deferred tax asset attributable to deductible loss carryforwards, classified as other.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from compensation and benefits costs.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from reserves and accruals.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from the allowance for doubtful accounts.

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Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized.

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Amount of deferred tax liability attributable to taxable temporary differences from intangible assets including goodwill.

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Amount of deferred tax liability attributable to taxable temporary differences classified as other.

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Amount of deferred tax consequences attributable to taxable temporary differences derived from prepaid expenses.

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Amount of deferred tax liability attributable to taxable temporary differences from property, plant, and equipment.

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Amount of deferred tax liability attributable to taxable temporary differences from unrealized gains on trading securities.

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