Business Acquisition Purchase Price Allocation Goodwill Not Expected Tax Deductible Amount

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- Definition

Business Acquisitions Purchase Price Allocation Goodwill Amount

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- Definition

Business Combination ,Aggregate Earnout Obligation, Maximum

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- Definition

Business Combination Aggregate Earnout Obligation Recorded Maximum

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- Definition

Business Combination, Annualize Revenue

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- Definition

Expiration lists

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- Definition

Fair Value Inputs, Attrition Rate

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No definition available.

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- Definition

Goodwill Related to Nondeductible Amortizable Intangible Assets

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- Definition

Maximum Potential Earnout Payable

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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No definition available.

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- Definition

Amount after tax of pro forma income from continuing operations as if the business combination had been completed at the beginning of a period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(2)-(3)
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- Definition

The pro forma net Income or Loss for the period as if the business combination or combinations had been completed at the beginning of a period.

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The pro forma revenue for a period as if the business combination or combinations had been completed at the beginning of the period.

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- Definition

Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

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- Definition

For transactions that are recognized separately from the acquisition of assets and assumptions of liabilities in the business combination, such as related to pre-existing relationships with the acquiree, this element represents the disclosure of the amount of acquisition related costs which have been expensed.

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- Definition

Amount of deferred tax liability attributable to taxable temporary differences.

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Interest rate used to find the present value of an amount to be paid or received in the future as an input to measure fair value. For example, but not limited to, weighted average cost of capital (WACC), cost of capital, cost of equity and cost of debt.

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Percentage of assumed long-term growth in revenues, used as an input to measure fair value.

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Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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No definition available.

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Gross carrying amount before accumulated amortization as of the balance sheet date of payments made to third parties in exchange for their agreement not to engage in specified competitive practices in specified geographic territories for a specified period of time.

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The amount of impairment loss recognized in the period resulting from the write-down of the carrying amount of a finite-lived intangible asset to fair value.

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- Definition

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

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Business Combinations - Additional Information (Detail)		3 Months Ended		9 Months Ended		189 Months Ended
Business Combinations - Additional Information (Detail)	Sep. 20, 2017 USD ($)	Sep. 30, 2017 USD ($) Entity	Sep. 30, 2016 USD ($) Entity	Sep. 30, 2017 USD ($) Entity	Sep. 30, 2016 USD ($) Entity	Sep. 30, 2017 USD ($) Entity
Business Acquisition [Line Items]
Maximum Potential Earnout Payable		$ 146,900,000		$ 146,900,000		$ 146,900,000
Accretion of the discount on acquisition		$ 4,900,000	$ 4,300,000	$ 15,200,000	$ 12,500,000
Number of companies acquired \| Entity		31	27	89	77	450
Aggregate amount of maximum earnout obligations related to acquisitions				$ 563,900,000
Aggregate amount of maximum earnout obligations related to acquisitions, recorded in consolidated balance sheet				274,300,000
Income (expense) related to net adjustments to estimated fair value of liability for earnout obligations		$ (5,700,000)	$ 200,000	(12,300,000)	$ (8,700,000)
Goodwill		228,100,000		228,100,000		$ 228,100,000
Expiration lists		188,900,000		188,900,000		188,900,000
Non-compete agreements		2,800,000		2,800,000		2,800,000
Write-off of amortizable intangible assets		4,500,000	1,500,000	6,200,000	1,800,000
Total revenues related to acquisitions in the aggregate		1,589,300,000	$ 1,517,500,000	4,600,000,000	$ 4,317,200,000
Brokerage and Risk Management [Member]
Business Acquisition [Line Items]
Goodwill		228,100,000		228,100,000		228,100,000
Expiration lists		188,900,000		188,900,000		188,900,000
Non-compete agreements		2,800,000		$ 2,800,000		2,800,000
Expiration Lists [Member] \| Minimum [Member]
Business Acquisition [Line Items]
Estimated useful lives of intangibles assets, years				3 years
Expiration Lists [Member] \| Maximum [Member]
Business Acquisition [Line Items]
Estimated useful lives of intangibles assets, years				15 years
Non-Compete Agreements [Member] \| Minimum [Member]
Business Acquisition [Line Items]
Estimated useful lives of intangibles assets, years				3 years
Non-Compete Agreements [Member] \| Maximum [Member]
Business Acquisition [Line Items]
Estimated useful lives of intangibles assets, years				5 years
Trade Names [Member] \| Minimum [Member]
Business Acquisition [Line Items]
Estimated useful lives of intangibles assets, years				3 years
Trade Names [Member] \| Maximum [Member]
Business Acquisition [Line Items]
Estimated useful lives of intangibles assets, years				5 years
2017 Acquisitions [Member] \| Market Approach Valuation Technique [Member] \| Minimum [Member]
Business Acquisition [Line Items]
Revenue growth rate				5.00%
Discount rate				7.50%
2017 Acquisitions [Member] \| Market Approach Valuation Technique [Member] \| Maximum [Member]
Business Acquisition [Line Items]
Revenue growth rate				17.00%
Discount rate				9.00%
2017 Acquisitions [Member] \| Income Approach Valuation Technique [Member] \| Minimum [Member]
Business Acquisition [Line Items]
Revenue growth rate				2.00%
Discount rate				12.00%
Attrition rate				5.00%
2017 Acquisitions [Member] \| Income Approach Valuation Technique [Member] \| Maximum [Member]
Business Acquisition [Line Items]
Revenue growth rate				3.30%
Discount rate				14.00%
Attrition rate				10.00%
2016 Acquisitions [Member] \| Income Approach Valuation Technique [Member] \| Minimum [Member]
Business Acquisition [Line Items]
Revenue growth rate				2.00%
Discount rate				12.00%
Attrition rate				5.00%
2016 Acquisitions [Member] \| Income Approach Valuation Technique [Member] \| Maximum [Member]
Business Acquisition [Line Items]
Revenue growth rate				3.30%
Discount rate				14.00%
Attrition rate				10.00%
Business Acquisition [Member]
Business Acquisition [Line Items]
Annualized revenue of business acquisitions				$ 143,000,000
Total revenues related to acquisitions in the aggregate				69,200,000
Net earnings				2,400,000
Business Acquisition [Member] \| Brokerage [Member]
Business Acquisition [Line Items]
Expiration lists		188,900,000		188,900,000		188,900,000
Non-compete agreements		2,800,000		2,800,000		2,800,000
Deferred tax liability		13,700,000		13,700,000		13,700,000
Goodwill related to nondeductible amortizable intangible assets				13,700,000
Business Acquisition [Member] \| Expiration Lists [Member] \| Brokerage [Member]
Business Acquisition [Line Items]
Business acquisition not deductible for income tax purposes		49,800,000		49,800,000		49,800,000
Business Acquisition [Member] \| Non-Compete Agreements [Member] \| Brokerage [Member]
Business Acquisition [Line Items]
Business acquisition not deductible for income tax purposes		$ 2,000,000		$ 2,000,000		$ 2,000,000
DiBrina Group [Member] \| Canada [Member] \| Definitive Agreement [Member]
Business Acquisition [Line Items]
Cash consideration	$ 42,800,000
Maximum Potential Earnout Payable	$ 24,000,000