Summary of Significant Accounting Policies - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2025 USD ($) clearing_house	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Significant Accounting Policies [Line Items]
Number of clearing houses | clearing_house	6
Number of clearing houses with required guaranty fund contributions | clearing_house	5
Useful life	12 years 9 months 18 days
Deferred contract costs	$ 60	$ 45
Equity capital	28,969	27,698	$ 25,786	$ 22,761
Foreign currency transaction loss	$ 18	15	12
Software Development
Significant Accounting Policies [Line Items]
Useful life	3 years
Software Development Except Services and NYSE Platforms
Significant Accounting Policies [Line Items]
Useful life	7 years
Employee stock
Significant Accounting Policies [Line Items]
Percentage of purchase price of common stock (in percentage)	85.00%
Foreign currency translation adjustments
Significant Accounting Policies [Line Items]
Equity capital	$ (186)	$ (285)	$ (230)	$ (278)