Business combination aggregate earnout obligation expected settlement in cash.

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- Definition

Business combination aggregate earnout obligation expected settlement in cash or stock at option.

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- Definition

Business Combination ,Aggregate Earnout Obligation, Maximum

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Business Combination Aggregate Earnout Obligation Recorded Maximum

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Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]

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Debt instrument redemption date.

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- Definition

Liabilities Recorded on Self-Insurance

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Number of employees.

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Number Of Letter Of Credit Issued

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Number of square feet.

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- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

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A credit or adjustment for government or taxing authority authorized decrease in taxes owed as a result of meeting certain tax policy conditions.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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The number of businesses acquired by the entity during the period.

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Present value of the accrual for product liability loss contingencies as of the balance sheet date (if the accrual qualifies for discounting).

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Amount of insurance benefit, claim, loss and settlement expenses incurred, as disclosed in supplementary insurance information.

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Amount of claim and benefit payable classified as other, disclosed in supplementary insurance information.

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Commitments, Contingencies and Off-Balance Sheet Arrangements - Additional Information (Detail)		3 Months Ended		9 Months Ended		237 Months Ended
	Jul. 29, 2021	Sep. 30, 2021 USD ($) ft² Entity LetterOfCredit	Sep. 30, 2020 Entity	Sep. 30, 2021 USD ($) ft² Entity Employee LetterOfCredit	Sep. 30, 2020 USD ($) Entity	Sep. 30, 2021 USD ($) ft² Entity LetterOfCredit
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Number of square feet \| ft²		360,000		360,000		360,000
Number of employees will accommodate at new facility \| Employee				2,000
Number of companies acquired \| Entity		44	55	80	126	602
Aggregate amount of maximum earnout obligations related to acquisitions				$ 1,026,100,000	$ 1,026,100,000
Aggregate amount of maximum earnout obligations related to acquisitions, recorded in consolidated balance sheet				578,700,000	$ 578,700,000
Aggregate amount of earnout obligation expected settlement in cash or stock at option		$ 560,500,000		560,500,000		$ 560,500,000
Aggregate amount of earnout obligation expected settlement in cash		$ 18,200,000		18,200,000		$ 18,200,000
Income tax credits and adjustments				$ 108,000,000.0
Security Deposit [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Number of letters of credit issued \| LetterOfCredit		1		1		1
Collateral [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Number of letters of credit issued \| LetterOfCredit		1		1		1
Self-Insurance Deductibles [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Number of letters of credit issued \| LetterOfCredit		2		2		2
Rent-A-Captive Facility [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Number of letters of credit issued \| LetterOfCredit		6		6		6
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
Insurance claim arise during ordinary course of business		$ 15,000,000.0		15,000,000.0		$ 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				20,000,000.0
Errors And Omissions [Member] \| Up to $27.0 Million [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Insurance claims, amount retained				10,000,000.0
Letter of Credit [Member] \| Security Deposit [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Debt		500,000		500,000		500,000
Letter of Credit [Member] \| Collateral [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Debt		900,000		900,000		900,000
Letter of Credit [Member] \| Self-Insurance Deductibles [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Debt		9,400,000		9,400,000		9,400,000
Liabilities recorded on self-insurance		18,700,000		18,700,000		18,700,000
Letter of Credit [Member] \| Rent-A-Captive Facility [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Debt		4,300,000		4,300,000		4,300,000
Minimum [Member] \| Errors And Omissions [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Actuarial range value		2,800,000		2,800,000		2,800,000
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		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		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		225,000,000.0
Maximum [Member] \| Errors And Omissions [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Actuarial range value		7,400,000		7,400,000		7,400,000
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		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		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		$ 365,000,000.0		$ 365,000,000.0		$ 365,000,000.0
Unconsolidated Investments in Enterprises [Member] \| Minimum [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Ownership interest		1.00%		1.00%		1.00%
Unconsolidated Investments in Enterprises [Member] \| Maximum [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Ownership interest		50.00%		50.00%		50.00%
Unsecured Senior Notes [Member] \| Fixed Rate of 2.50%, Balloon Due May 20, 2031 [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Notes redemption date	Aug. 13, 2021
Unsecured Senior Notes [Member] \| Fixed Rate of 2.50%, Balloon Due May 20, 2031 [Member] \| Private Placement [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Notes redemption date	Aug. 13, 2021