Organization and Summary of Significant Accounting Policies - Additional Information (Detail)	12 Months Ended
	Apr. 30, 2021 USD ($) Segment	Apr. 30, 2020 USD ($) Facility	Apr. 30, 2019 USD ($)
Organization And Summary Of Significant Accounting Policies [Line Items]
Number of business segments | Segment	7
Number of line of business | Segment	4
Credit loss for available for sales debt securities	$ 0	$ 0	$ 0
Business acquisitions adjustment, increase in goodwill	2,643,000
ROU assets, impairment charge		2,282,000
Write-off of long-lived assets		2,654,000
Impairment of long-lived assets	0		0
Impairment of goodwill	0
Impairment of intangible assets	0	0
Purchase price allocated to indefinite lived trade name intangible assets			106,600,000
Performance-related bonus expenses	$ 287,300,000	197,100,000	257,300,000
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	$ 161,295,000	146,408,000
ASU 2016-13
Organization And Summary Of Significant Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted	true
Change in accounting principle, accounting standards update, adoption date	May 01, 2020
Change in accounting principle, accounting standards update, immaterial effect	true
ASU 2017-04
Organization And Summary Of Significant Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted	true
Change in accounting principle, accounting standards update, adoption date	May 01, 2020
Change in accounting principle, accounting standards update, immaterial effect	true
ASU 2018-13
Organization And Summary Of Significant Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted	true
Change in accounting principle, accounting standards update, adoption date	May 01, 2020
Change in accounting principle, accounting standards update, immaterial effect	true
ASU 2018-15
Organization And Summary Of Significant Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted	true
Change in accounting principle, accounting standards update, adoption date	May 01, 2020
Change in accounting principle, accounting standards update, immaterial effect	true
ASU 2019-12
Organization And Summary Of Significant Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted	true
Change in accounting principle, accounting standards update, adoption date	May 01, 2020
Change in accounting principle, accounting standards update, immaterial effect	true
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	$ 161,300,000	146,400,000
Executive Capital Accumulation Plan
Organization And Summary Of Significant Accounting Policies [Line Items]
Deferred compensation arrangement vesting period	5 years
General and Administrative Expenses
Organization And Summary Of Significant Accounting Policies [Line Items]
Impairment of intangible assets			106,600,000
Foreign currency gains (losses)	$ (2,700,000)	$ (4,100,000)	(1,700,000)
Digital
Organization And Summary Of Significant Accounting Policies [Line Items]
Impairment of intangible assets			$ 29,600,000
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
Acquired Companies
Organization And Summary Of Significant Accounting Policies [Line Items]
Business acquisitions adjustment, increase in goodwill	$ 2,600,000
Number of office leases closed | Facility		16
ROU assets, impairment charge		$ 2,300,000
Acquired Companies | Digital
Organization And Summary Of Significant Accounting Policies [Line Items]
ROU assets, impairment charge		2,300,000
Acquired Companies | Leasehold Improvements and Furniture and Fixtures | Digital
Organization And Summary Of Significant Accounting Policies [Line Items]
Write-off of long-lived assets		$ 400,000
Mexican Subsidiary
Organization And Summary Of Significant Accounting Policies [Line Items]
Percentage of Noncontrolling interest in subsidiary	51.00%