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v3.23.3

Business Combinations - Additional Information (Detail) $ in Millions |  |  | 3 Months Ended | 9 Months Ended | 261 Months Ended |
--- | --- | --- | --- | --- | --- | ---
Oct. 24, 2023 USD ($) Office State | Apr. 03, 2023 Employee | Sep. 30, 2023 USD ($) Entity | Sep. 30, 2022 USD ($) Entity | Sep. 30, 2023 USD ($) Entity | Sep. 30, 2022 USD ($) Entity | Sep. 30, 2023 USD ($) Entity | Sep. 19, 2023 USD ($)
Business Acquisition [Line Items] |  |  |  |  |  |  |  |
Accretion of the discount on acquisition |  |  | $ 17.9 | $ 19.4 | $ 57.5 | $ 42.8 |  |
Income (expense) related to net adjustments to estimated fair value of liability for earnout obligations |  |  | $ 20.4 | $ 35.6 | $ (8.8) | $ 71.9 |  |
Number of companies acquired | Entity |  |  | 20 | 27 | 59 | 70 | 687 |
Aggregate amount of maximum earnout obligations related to acquisitions |  |  |  |  | $ 1,915.7 |  |  |
Aggregate amount of maximum earnout obligations related to acquisitions, recorded in consolidated balance sheet |  |  |  |  | 899.0 |  |  |
Aggregate amount of earnout obligation expected settlement in cash or stock at option |  |  | $ 486.6 |  | 486.6 |  | $ 486.6 |
Aggregate amount of earnout obligation expected settlement in cash |  |  | 412.4 |  | 412.4 |  | 412.4 |
Goodwill |  |  | 957.9 |  | 957.9 |  | 957.9 |
Expiration lists |  |  | 667.9 |  | 667.9 |  | 667.9 |
Non-compete agreements |  |  | 15.6 |  | 15.6 |  | 15.6 |
Trade names |  |  | 4.2 |  | 4.2 |  | 4.2 |
Total revenues |  |  | 2,500.4 | $ 2,159.0 | 7,781.9 | $ 6,877.5 |  |
Brokerage Management [Member] |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |
Goodwill |  |  | 957.9 |  | 957.9 |  | 957.9 |
Expiration lists |  |  | 667.9 |  | 667.9 |  | 667.9 |
Non-compete agreements |  |  | 15.6 |  | 15.6 |  | 15.6 |
Trade names |  |  | 4.2 |  | 4.2 |  | 4.2 |
Brokerage and Risk Management [Member] |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |
Write-off of amortizable intangible assets |  |  |  |  | 3.3 | $ 0.4 |  |
Brokerage [Member] | Expiration Lists [Member] |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |
Business acquisition not deductible for income tax purposes |  |  | 441.4 |  | 441.4 |  | 441.4 |
Brokerage [Member] | Non-Compete Agreements [Member] |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |
Business acquisition not deductible for income tax purposes |  |  | 12.4 |  | 12.4 |  | 12.4 |
Brokerage [Member] | Trade Names [Member] |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |
Business acquisition not deductible for income tax purposes |  |  | $ 2.9 |  | $ 2.9 |  | $ 2.9 |
Minimum [Member] | Expiration Lists [Member] |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |
Estimated useful lives of intangibles assets, years |  |  | 2 years |  | 2 years |  | 2 years |
Minimum [Member] | Non-Compete Agreements [Member] |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |
Estimated useful lives of intangibles assets, years |  |  | 2 years |  | 2 years |  | 2 years |
Minimum [Member] | Trade Names [Member] |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |
Estimated useful lives of intangibles assets, years |  |  | 2 years |  | 2 years |  | 2 years |
Maximum [Member] | Expiration Lists [Member] |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |
Estimated useful lives of intangibles assets, years |  |  | 15 years |  | 15 years |  | 15 years |
Maximum [Member] | Non-Compete Agreements [Member] |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |
Estimated useful lives of intangibles assets, years |  |  | 6 years |  | 6 years |  | 6 years |
Maximum [Member] | Trade Names [Member] |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |
Estimated useful lives of intangibles assets, years |  |  | 15 years |  | 15 years |  | 15 years |
2023 Acquisitions [Member] | Valuation, Market Approach [Member] | Measurement Input, Discount Rate [Member] | Minimum [Member] |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |
Measurement input |  |  | 0.05 |  | 0.05 |  | 0.05 |
2023 Acquisitions [Member] | Valuation, Market Approach [Member] | Measurement Input, Discount Rate [Member] | Maximum [Member] |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |
Measurement input |  |  | 0.20 |  | 0.20 |  | 0.20 |
2023 Acquisitions [Member] | Valuation, Income Approach | Measurement Input, Discount Rate [Member] | Minimum [Member] |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |
Measurement input |  |  | 0.08 |  | 0.08 |  | 0.08 |
2023 Acquisitions [Member] | Valuation, Income Approach | Measurement Input, Discount Rate [Member] | Maximum [Member] |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |
Measurement input |  |  | 0.09 |  | 0.09 |  | 0.09 |
2022 Acquisitions [Member] | Valuation, Market Approach [Member] | Measurement Input, Long-term Revenue Growth Rate [Member] | Minimum [Member] |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |
Measurement input |  |  | 0.03 |  | 0.03 |  | 0.03 |
2022 Acquisitions [Member] | Valuation, Market Approach [Member] | Measurement Input, Long-term Revenue Growth Rate [Member] | Maximum [Member] |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |
Measurement input |  |  | 0.05 |  | 0.05 |  | 0.05 |
2022 Acquisitions [Member] | Valuation, Income Approach | Minimum [Member] |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |
Attrition rate |  |  |  |  | 5.00% |  |  |
2022 Acquisitions [Member] | Valuation, Income Approach | Maximum [Member] |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |
Attrition rate |  |  |  |  | 25.50% |  |  |
2022 Acquisitions [Member] | Valuation, Income Approach | Measurement Input, Long-term Revenue Growth Rate [Member] | Minimum [Member] |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |
Measurement input |  |  | 0.09 | 0.09 | 0.09 | 0.09 | 0.09 |
2022 Acquisitions [Member] | Valuation, Income Approach | Measurement Input, Long-term Revenue Growth Rate [Member] | Maximum [Member] |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |
Measurement input |  |  | 0.11 | 0.11 | 0.11 | 0.11 | 0.11 |
Business Acquisition [Member] |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |
Annualized revenue of business acquisitions |  |  |  |  | $ 475.3 |  |  |
Total revenues |  |  |  |  | 223.3 |  |  |
Net earnings |  |  |  |  | (1.9) |  |  |
Net earnings before interest, income taxes, depreciation, amortization and change in estimated acquisition earnout payables |  |  |  |  | 43.5 |  |  |
Business Acquisition [Member] | Brokerage [Member] |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |
Expiration lists |  |  | $ 667.9 |  | 667.9 |  | $ 667.9 |
Non-compete agreements |  |  | 15.6 |  | 15.6 |  | 15.6 |
Trade names |  |  | 4.2 |  | 4.2 |  | 4.2 |
Deferred tax liability |  |  | $ 113.5 |  | $ 113.5 |  | $ 113.5 |
Cadence Insurance [Member] | Subsequent Event [Member] |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |
Consideration amount | $ 749.0 |  |  |  |  |  |  |
Consideration amount net of discounted tax benefit | $ 155.0 |  |  |  |  |  |  |
Number of offices operating | Office | 34 |  |  |  |  |  |  |
Number of states operating | State | 9 |  |  |  |  |  |  |
BCHR Holdings, L.P [Member] |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |
Number of employees | Employee |  | 2,300 |  |  |  |  |  |
Number of employees with credentialed actuaries | Employee |  | 220 |  |  |  |  |  |
Eastern Insurance Group, LLC [Member] |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |
Expected business consideration to be transferred |  |  |  |  |  |  |  | $ 510.0

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