Consolidated Statements of Income - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Revenues:
Total revenues	$ 4,714.2	$ 4,094.5	$ 3,773.5
Cost of revenues:
Total cost of revenues	2,285.1	2,022.1	1,855.5
Revenues less cost of revenues	2,429.1	2,072.4	1,918.0
Operating expenses:
Compensation and benefits	500.8	462.4	425.8
Depreciation and amortization	122.4	133.0	158.0
Technology support services	107.6	102.8	99.7
Professional fees and outside services	91.5	94.8	92.0
Travel and promotional expenses	42.1	45.8	37.6
Facilities costs	26.2	24.6	25.7
Acquisition-related costs	0.3	1.3	7.4
Impairment of assets	46.7	81.0	0.0
Other expenses	24.4	28.3	13.9
Total operating expenses	962.0	974.0	860.1
Operating income	1,467.1	1,098.4	1,057.9
Non-operating (expenses) income:
Interest expense	(52.3)	(51.5)	(62.4)
Interest income	49.4	27.3	12.0
Earnings on investments, net	92.8	29.0	39.5
Other income (expense), net	9.6	(19.4)	0.6
Income before income tax provision	1,566.6	1,083.8	1,047.6
Income tax provision	466.6	318.9	286.2
Net income	1,100.0	764.9	761.4
Net income allocated to participating securities	(5.2)	(3.9)	(3.9)
Net income allocated to common stockholders	1,094.8	761.0	757.5
Net income allocated to common stockholders	$ 1,094.8	$ 761.0	$ 757.5
Basic earnings per share (in dollars per share)	$ 10.46	$ 7.24	$ 7.16
Diluted earnings per share (in dollars per share)	$ 10.42	$ 7.21	$ 7.13
Basic weighted average shares outstanding (in shares)	104.7	105.1	105.8
Diluted weighted average shares outstanding (in shares)	105.1	105.5	106.2
Cash and spot markets
Revenues:
Total revenues	$ 1,834.8	$ 1,670.0	$ 1,445.1
Data Vantage
Revenues:
Total revenues	635.5	576.6	539.2
Derivatives markets
Revenues:
Total revenues	2,243.9	1,847.9	1,789.2
Liquidity payments
Cost of revenues:
Total cost of revenues	1,709.7	1,329.1	1,385.8
Routing and clearing
Cost of revenues:
Total cost of revenues	80.4	68.3	79.1
Regulatory fees cost of revenues
Revenues:
Total revenues	285.4	426.3	223.7
Cost of revenues:
Total cost of revenues	238.7	391.4	185.7
Royalty fees and other cost of revenues
Cost of revenues:
Total cost of revenues	$ 256.3	$ 233.3	$ 204.9