Organization and Summary of Significant Accounting Policies - Additional Information (Detail)		3 Months Ended	12 Months Ended
	Jan. 31, 2023 USD ($)	Apr. 30, 2023 USD ($)	Apr. 30, 2023 USD ($) segment business	Apr. 30, 2022 USD ($)	Apr. 30, 2021 USD ($)
Organization And Summary Of Significant Accounting Policies [Line Items]
Number of business segments | segment			8
Number of line of business | business			5
Credit loss for available for sales debt securities		$ 0	$ 0	$ 0	$ 0
Impairment of right-of-use assets			5,471,000	7,392,000	0
Impairment of fixed assets			4,375,000	1,915,000	0
Impairment of goodwill	$ 0	0	0
Impairment of intangible assets			0	0	0
Performance-related bonus expenses			$ 409,400,000	447,600,000	287,300,000
Percentage that actuarial gain or loss must exceed the greater of PBO or market value plan assets			10.00%
Cash surrender value of company-owned life insurance policies, net of loans		197,998,000	$ 197,998,000	183,308,000
General and Administrative Expenses
Organization And Summary Of Significant Accounting Policies [Line Items]
Foreign currency gains (losses)			(2,000,000)	(1,200,000)	(2,700,000)
CSV of COLI Contracts
Organization And Summary Of Significant Accounting Policies [Line Items]
Cash surrender value of company-owned life insurance policies, net of loans		$ 198,000,000	$ 198,000,000	$ 183,300,000
Executive Capital Accumulation Plan
Organization And Summary Of Significant Accounting Policies [Line Items]
Deferred compensation arrangement vesting period			5 years	5 years
Minimum
Organization And Summary Of Significant Accounting Policies [Line Items]
Intangible assets estimated useful lives			1 year
Amortization of long-term retention awards			4 years
Maximum
Organization And Summary Of Significant Accounting Policies [Line Items]
Intangible assets estimated useful lives			24 years
Amortization of long-term retention awards			5 years
Software and Software Development Costs | Minimum
Organization And Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful life			3 years
Software and Software Development Costs | Maximum
Organization And Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful life			10 years
Other Capitalized Property Plant and Equipment | Minimum
Organization And Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful life			3 years
Other Capitalized Property Plant and Equipment | Maximum
Organization And Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful life			10 years
Leasehold Improvements and Furniture and Fixtures
Organization And Summary Of Significant Accounting Policies [Line Items]
Impairment of fixed assets			$ 4,400,000	$ 1,900,000	$ 0
Mexican Subsidiary
Organization And Summary Of Significant Accounting Policies [Line Items]
Percentage of noncontrolling interest in subsidiary		51.00%	51.00%