Goodwill and Intangible Assets - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024	Dec. 31, 2024
Goodwill [Line Items]
Amortization expense associated with identifiable intangible assets	$ 4.9	$ 5.0	$ 9.2	$ 10.0
Estimated total amortization expense 2025	20.0		20.0
Estimated total amortization expense 2026	19.7		19.7
Estimated total amortization expense 2027	18.3		18.3
Estimated total amortization expense 2028	16.8		16.8
Estimated total amortization expense 2029	15.8		15.8
Indefinite-lived Intangible Assets [Member]
Goodwill [Line Items]
Goodwill and intangible assets with indefinite lives	$ 286.0		$ 286.0		$ 236.7

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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+ Details

MARKETAXESS HOLDINGS INC 10-Q