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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (c)(1)
-URI https://asc.fasb.org/extlink&oid=126975305&loc=d3e6927-128479

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 35
-Paragraph 1
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126966325&loc=d3e6819-128478

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 25
-Paragraph 6
-URI https://asc.fasb.org/extlink&oid=6911189&loc=d3e6408-128476

Name:	us-gaap_BusinessCombinationContingentConsiderationLiability
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

FAIR VALUE MEASUREMENT - Narrative (Details) $ in Millions	9 Months Ended
FAIR VALUE MEASUREMENT - Narrative (Details) $ in Millions	Sep. 30, 2022 USD ($) item	Sep. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)
Segment Reporting Information
Contingent consideration liabilities	$ 47.5		$ 70.5
Payment of contingent consideration liabilities	$ 33.2	$ 7.1
Number of other stock exchanges \| item	3
Hanweck, FT Options, Trade Alert And Cboe Asia Pacific
Segment Reporting Information
Payment of contingent consideration liabilities	$ 7.3
Recurring
Segment Reporting Information
Contingent consideration liabilities	$ 47.5		$ 70.5