Represents the information pertaining to business combination, maximum measurement period for fair value determination.

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- Definition

Represents the information pertaining to fair value adjustments to reduce revenue.

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Represents the information pertaining to number of acquisitions, purchase accounting not yet finalized.

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This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, including the costs of maintaining an internal acquisitions department; and may include costs of registering and issuing debt and equity securities.

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- Definition

Amount of increase (decrease) in the value of a contingent consideration liability, including, but not limited to, differences arising upon settlement.

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Amount of liability recognized arising from contingent consideration in a business combination.

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Amount of liability recognized arising from contingent consideration in a business combination, expected to be settled within one year or the normal operating cycle, if longer.

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Amount of liability recognized arising from contingent consideration in a business combination, expected to be settled beyond one year or the normal operating cycle, if longer.

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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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Aggregate carrying value as of the balance sheet date of the liabilities for all deferred compensation arrangements payable beyond one year (or the operating cycle, if longer).

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Aggregate carrying value as of the balance sheet date of the liabilities for all deferred compensation arrangements payable within one year (or the operating cycle, if longer). Represents currently earned compensation under compensation arrangements that is not actually paid until a later date.

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Acquisitions - Additional Information (Details) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Business Combination, Separately Recognized Transactions [Line Items]
Fair value of the contingent consideration included in accruals and other current liabilities			$ 5,100	$ 2,390
Contingent consideration from acquisitions	$ 3,583		5,100	2,390
Reclassifications to noncontingent consideration from acquisitions	(1,340)	$ 62	62	272
Other Noncurrent Liabilities [Member]
Business Combination, Separately Recognized Transactions [Line Items]
Contingent consideration from acquisitions			1,499	1,926
Series of Individually Immaterial Business Acquisitions
Business Combination, Separately Recognized Transactions [Line Items]
Acquisition contingent consideration	5,143		6,599
Fair value of the contingent consideration included in accruals and other current liabilities	1,560		1,499
Contingent consideration from acquisitions	$ 3,583		5,100
Reclassifications to noncontingent consideration from acquisitions				8,516
Fair value adjustments to reduce revenue			$ 553	2,469
Number of acquisitions, purchase accounting not yet finalized			3
Business combination, maximum measurement period for fair value determination			1 year
Acquisition and integration costs			$ 950	1,361
Series of Individually Immaterial Business Acquisitions \| Accruals and other current liabilities
Business Combination, Separately Recognized Transactions [Line Items]
Acquisition contingent consideration			6,599	4,316
Current deferred payment obligations			5,999	11,019
Series of Individually Immaterial Business Acquisitions \| Other Noncurrent Liabilities [Member]
Business Combination, Separately Recognized Transactions [Line Items]
Long-term deferred payment obligations			$ 1,499	$ 2,826