Business combination period of contingent consideration payable.

No definition available.

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- Definition

Weighted average amortization period of finite-lived intangible assets acquired either individually or as part of a group of assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
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+ Details

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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.

+ References

No definition available.

+ Details

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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.

+ References

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Balance Type:	credit
Period Type:	duration

- Definition

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

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
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Balance Type:	debit
Period Type:	duration

- Definition

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.

+ References

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Balance Type:	credit
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- Definition

The amount of identifiable intangible assets recognized as of the acquisition date.

+ References

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Balance Type:	debit
Period Type:	instant

- Definition

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

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-Publisher FASB
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+ Details

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- Definition

The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

+ References

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- Details

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- Details

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- Details

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- Details

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- Details

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- Details

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Acquisitions - Additional Information (Detail) - USD ($) $ in Thousands			9 Months Ended
	Apr. 09, 2021	Nov. 30, 2020	Sep. 30, 2021	Dec. 31, 2020
Business Acquisition [Line Items]
Contingent consideration payable			$ 26,900
Goodwill			$ 154,789	$ 147,388
Maximum [Member]
Business Acquisition [Line Items]
Business combination, contingent consideration payment period			24 months
Minimum [Member]
Business Acquisition [Line Items]
Business combination, contingent consideration payment period			18 months
MuniBrokers LLC [Member]
Business Acquisition [Line Items]
Cash consideration	$ 17,100
Business combination, contingent consideration payment period	2 years
Amortizable intangible assets	$ 32,000
Goodwill	7,400
MuniBrokers LLC [Member] \| Accounts Payable, Accrued Expenses and Other Liabilities [Member]
Business Acquisition [Line Items]
Cash consideration	17,100
Contingent consideration payable	22,500
Accounting purchase price	39,600
MuniBrokers LLC [Member] \| Maximum [Member]
Business Acquisition [Line Items]
Contingent consideration payable	$ 25,000
MuniBrokers LLC [Member] \| Maximum [Member] \| Customer Relationships and Technology [Member]
Business Acquisition [Line Items]
Useful lives	15 years
MuniBrokers LLC [Member] \| Minimum [Member] \| Customer Relationships and Technology [Member]
Business Acquisition [Line Items]
Useful lives	1 year
Regulatory Services GmbH of Deutsche Borse Group [Member]
Business Acquisition [Line Items]
Cash consideration		$ 22,500
Business combination, contingent consideration payment period		18 months
Amortizable intangible assets		$ 37,400
Amount of increase in the value of contingent consideration payable			$ 4,400
Regulatory Services GmbH of Deutsche Borse Group [Member] \| Accounts Payable, Accrued Expenses and Other Liabilities [Member]
Business Acquisition [Line Items]
Contingent consideration payable		14,700
Regulatory Services GmbH of Deutsche Borse Group [Member] \| Maximum [Member]
Business Acquisition [Line Items]
Contingent consideration payable		$ 24,600