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Organization and Summary of Significant Accounting Policies - Additional Information (Detail) | 12 Months Ended
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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% |  |

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