Consolidated Statements of Income - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Revenues:
Total revenues	$ 4,094.5	$ 3,773.5	$ 3,958.5
Cost of revenues:
Total cost of revenues	2,022.1	1,855.5	2,216.8
Revenues less cost of revenues	2,072.4	1,918.0	1,741.7
Operating expenses:
Compensation and benefits	462.4	425.8	363.0
Depreciation and amortization	133.0	158.0	166.8
Technology support services	102.8	99.7	77.7
Professional fees and outside services	94.8	92.0	89.0
Travel and promotional expenses	45.8	37.6	23.7
Facilities costs	24.6	25.7	25.1
Acquisition-related costs	1.3	7.4	19.9
Impairment of goodwill	0.0	0.0	460.9
Impairment of intangible assets	81.0	0.0	0.0
Other expenses	28.3	13.9	26.0
Total operating expenses	974.0	860.1	1,252.1
Operating income	1,098.4	1,057.9	489.6
Non-operating (expenses) income:
Interest expense	(51.5)	(62.4)	(60.0)
Interest income	27.3	12.0	3.6
Earnings on investments	29.0	39.5	7.2
Other (expense) income, net	(19.4)	0.6	(7.5)
Income before income tax provision	1,083.8	1,047.6	432.9
Income tax provision	318.9	286.2	197.9
Net income	764.9	761.4	235.0
Net income allocated to participating securities	(3.9)	(3.9)	(0.9)
Net income allocated to common stockholders	761.0	757.5	234.1
Net income allocated to common stockholders	$ 761.0	$ 757.5	$ 234.1
Basic earnings per share (in dollars per share)	$ 7.24	$ 7.16	$ 2.20
Diluted earnings per share (in dollars per share)	$ 7.21	$ 7.13	$ 2.19
Basic weighted average shares outstanding (in shares)	105.1	105.8	106.3
Diluted weighted average shares outstanding (in shares)	105.5	106.2	106.7
Cash and spot markets
Revenues:
Total revenues	$ 1,670.0	$ 1,445.1	$ 1,777.6
Data Vantage
Revenues:
Total revenues	576.6	539.2	497.0
Derivatives markets
Revenues:
Total revenues	1,847.9	1,789.2	1,683.9
Liquidity payments
Cost of revenues:
Total cost of revenues	1,329.1	1,385.8	1,670.2
Routing and clearing
Cost of revenues:
Total cost of revenues	68.3	79.1	83.2
Section 31 fees
Cost of revenues:
Total cost of revenues	391.4	185.7	329.8
Royalty fees and other cost of revenues
Cost of revenues:
Total cost of revenues	$ 233.3	$ 204.9	$ 133.6