Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Cash flows from operating activities:
Net income	$ 1,100.0	$ 764.9	$ 761.4
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	122.4	133.0	158.0
Impairment of assets	46.7	81.0	0.0
Stock-based compensation expense	50.4	41.8	41.3
(Gain) impairment of minority investments	(5.1)	31.6	1.8
Change in contingent consideration	0.0	2.0	(14.4)
Equity earnings on investments	(84.2)	(26.5)	(36.9)
Benefit for deferred income taxes	(8.4)	(23.6)	(15.2)
Other loss (gain) adjustments, net	2.2	(0.7)	4.0
Changes in assets and liabilities:
Accounts receivable	79.4	(124.3)	39.4
Restricted cash and cash equivalents and customer bank deposits (included in margin deposits, clearing funds, and interoperability funds)	528.5	76.0	282.6
Income taxes receivable	6.1	0.5	(26.3)
Other current assets	17.1	(26.0)	(17.4)
Other assets	24.8	17.3	(26.7)
Accounts payable and accrued liabilities	6.5	(36.4)	(19.1)
Section 31 fees payable	(181.8)	130.1	(95.2)
Deferred revenue	0.5	0.5	(5.8)
Income taxes payable	48.5	0.8	(2.8)
Unrecognized tax benefits	0.0	61.2	47.7
Other liabilities	(1.0)	(2.6)	(0.8)
Net cash flows provided by operating activities	1,752.6	1,100.6	1,075.6
Cash flows from investing activities:
Proceeds from investments	441.8	0.0	0.0
Contributions to investments	(2.5)	(40.2)	(57.1)
Purchases of available-for-sale financial investments	(174.8)	(115.6)	(89.8)
Proceeds from maturities of available-for-sale financial investments	248.1	67.9	135.7
Proceeds from sale of intangible assets	1.6	0.1	0.8
Proceeds from sale of property held for sale	0.0	3.3	0.0
Proceeds from sale of property and equipment	0.0	0.7	0.0
Proceeds from notes receivable	7.0	2.8	0.0
Proceeds from insurance	0.0	0.1	0.3
Purchases of property and equipment and leasehold improvements, net	(71.0)	(60.9)	(45.0)
Net cash flows provided by (used in) investing activities	450.2	(141.8)	(55.1)
Cash flows from financing activities:
Principal payments of current portion of long-term debt	0.0	0.0	(305.0)
Cash dividends on common stock	(284.3)	(249.4)	(223.5)
Repurchases of common stock from employee stock plans	(29.8)	(29.5)	(13.9)
Shares issued under employee stock purchase plan	9.2	8.6	(16.7)
Payments of contingent consideration related to acquisitions	0.0	(13.9)	(13.1)
Payments for Cboe Digital non-recourse notes and warrants wind down	0.0	(6.0)	0.0
Purchase of common stock, including commissions and excise taxes	(66.7)	(204.8)	(83.9)
Net cash flows used in financing activities	(371.6)	(495.0)	(656.1)
Effect of foreign currency exchange rates on cash, cash equivalents, and restricted cash and cash equivalents	271.8	(95.1)	52.8
Increase in cash, cash equivalents, and restricted cash and cash equivalents	2,103.0	368.7	417.2
Beginning of period	1,765.8	1,397.1	979.9
End of period	3,868.8	1,765.8	1,397.1
Reconciliation of cash, cash equivalents, and restricted cash and cash equivalents:
Cash and cash equivalents	2,216.5	915.3	543.2
Restricted cash and cash equivalents (included in margin deposits, clearing funds, and interoperability funds)	1,617.0	841.4	834.8
Restricted cash and cash equivalents (included in cash and cash equivalents)	0.0	5.0	0.0
Restricted cash and cash equivalents (included in other current assets)	34.1	0.0	5.1
Customer bank deposits (included in margin deposits, clearing funds, and interoperability funds)	1.2	4.1	14.0
Total	3,868.8	1,765.8	1,397.1
Supplemental disclosure of cash transactions:
Cash paid for income taxes, net	391.6	362.4	286.4
Cash paid for interest	91.7	100.1	56.7
Supplemental disclosure of noncash investing activities:
Intangible assets earned or acquired	0.0	1.2	0.0
Note receivable from property held for sale	0.0	6.4	0.0
Supplemental disclosure of noncash financing activities:
Excise tax on purchases of common stock	0.0	1.3	0.0
Cboe Digital investor member revenue asset	0.0	16.2	(3.2)
Cboe Digital non-recourse notes and warrants	$ 0.0	$ (16.2)	$ 3.2