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Commitments, Contingencies and Off-Balance Sheet Arrangements - Additional Information (Detail) | 3 Months Ended | 279 Months Ended
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Mar. 31, 2025 USD ($) ft² Entity LetterOfCredit | Mar. 31, 2024 USD ($) Entity | Mar. 31, 2025 USD ($) ft² Entity LetterOfCredit
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items] |  |  |
Number of square feet | ft² | 360,000 |  | 360,000
Number of companies acquired | Entity | 28 | 37 | 761
Aggregate amount of maximum earnout obligations related to acquisitions | $ 2,154,000,000 |  |
Aggregate amount of maximum earnout obligations related to acquisitions, recorded in consolidated balance sheet | 1,368,000,000 |  |
Aggregate amount of earnout obligation expected settlement in cash or stock at option | 576,300,000 |  | $ 576,300,000
Aggregate amount of earnout obligation expected settlement in cash | $ 791,700,000 |  | $ 791,700,000
Collateral [Member] |  |  |
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items] |  |  |
Number of letters of credit issued | LetterOfCredit | 1 |  | 1
Self-Insurance Deductibles [Member] |  |  |
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items] |  |  |
Number of letters of credit issued | LetterOfCredit | 1 |  | 1
Rent-A-Captive Facility [Member] |  |  |
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items] |  |  |
Number of letters of credit issued | LetterOfCredit | 8 |  | 8
Errors And Omissions [Member] | Up to $4.5 Million [Member] |  |  |
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items] |  |  |
Insurance claims, amount retained | $ 2,000,000.0 |  |
Errors And Omissions [Member] | Up to $10 Million [Member] |  |  |
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items] |  |  |
Insurance claims, amount retained | 15,000,000.0 |  |
Errors And Omissions [Member] | Up to $20.0 Million [Member] |  |  |
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items] |  |  |
Insurance claims, amount retained | 10,000,000.0 |  |
Errors And Omissions [Member] | Up to $27.0 Million [Member] |  |  |
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items] |  |  |
Insurance claims, amount retained | 20,000,000.0 |  |
Letter of Credit [Member] | Security Deposit [Member] |  |  |
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items] |  |  |
Debt | 800,000 |  | $ 800,000
Letter of Credit [Member] | Self-Insurance Deductibles [Member] |  |  |
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items] |  |  |
Debt | 400,000 |  | 400,000
Liabilities recorded on self-insurance |  | $ 11,300,000 |
Letter of Credit [Member] | Rent-A-Captive Facility [Member] |  |  |
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items] |  |  |
Debt | 13,000,000 |  | 13,000,000
Minimum [Member] | Errors And Omissions [Member] |  |  |
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items] |  |  |
Loss Contingency Accrual, Product Liability, Net, Total | 6,900,000 |  | 6,900,000
Minimum [Member] | Errors And Omissions [Member] | Up to $4.5 Million [Member] |  |  |
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items] |  |  |
Insurance claim arise during ordinary course of business | 15,000,000.0 |  | 15,000,000.0
Minimum [Member] | Errors And Omissions [Member] | Up to $20.0 Million [Member] |  |  |
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items] |  |  |
Insurance claim arise during ordinary course of business | 100,000,000.0 |  | 100,000,000.0
Minimum [Member] | Errors And Omissions [Member] | Up to $27.0 Million [Member] |  |  |
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items] |  |  |
Insurance claim arise during ordinary course of business | 225,000,000.0 |  | 225,000,000.0
Maximum [Member] | Errors And Omissions [Member] |  |  |
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items] |  |  |
Loss Contingency Accrual, Product Liability, Net, Total | 8,200,000 |  | 8,200,000
Maximum [Member] | Errors And Omissions [Member] | Up to $4.5 Million [Member] |  |  |
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items] |  |  |
Insurance claim arise during ordinary course of business | 100,000,000.0 |  | 100,000,000.0
Maximum [Member] | Errors And Omissions [Member] | Up to $20.0 Million [Member] |  |  |
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items] |  |  |
Insurance claim arise during ordinary course of business | 225,000,000.0 |  | 225,000,000.0
Maximum [Member] | Errors And Omissions [Member] | Up to $27.0 Million [Member] |  |  |
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items] |  |  |
Insurance claim arise during ordinary course of business | $ 400,000,000.0 |  | $ 400,000,000.0
Unconsolidated Investments in Enterprises [Member] | Minimum [Member] |  |  |
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items] |  |  |
Ownership interest | 1.00% |  | 1.00%
Unconsolidated Investments in Enterprises [Member] | Maximum [Member] |  |  |
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items] |  |  |
Ownership interest | 50.00% |  | 50.00%

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