Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities:
Net income	$ 764.9	$ 761.4	$ 235.0
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	133.0	158.0	166.8
Impairment of intangible assets or goodwill	81.0	0.0	460.9
Stock-based compensation expense	41.8	41.3	30.7
Impairment of investments	31.6	1.8	10.6
Provision for accounts receivable credit losses	3.1	4.0	1.1
Amortization of debt issuance cost and debt discount	2.3	2.6	2.4
Change in contingent consideration	2.0	(14.4)	(5.2)
Equity earnings on investments	(26.5)	(36.9)	(4.2)
Benefit for deferred income taxes	(23.6)	(15.2)	(155.7)
Gain on investment	0.0	0.0	(7.5)
Gain on Cboe Digital non-recourse notes and warrants wind down	(2.4)	0.0	0.0
Other	(3.7)	(2.6)	0.3
Changes in assets and liabilities:
Accounts receivable	(124.3)	39.4	(49.8)
Restricted cash and cash equivalents and customer bank deposits (included in margin deposits, clearing funds, and interoperability funds)	76.0	282.6	(217.5)
Income taxes receivable	0.5	(26.3)	(5.4)
Other current assets	(26.0)	(17.4)	(4.0)
Other assets	17.3	(26.7)	(20.8)
Accounts payable and accrued liabilities	(36.4)	(19.1)	38.8
Section 31 fees payable	130.1	(95.2)	106.3
Deferred revenue	0.5	(5.8)	(4.1)
Income taxes payable	0.8	(2.8)	(3.8)
Unrecognized tax benefits	61.2	47.7	89.1
Other liabilities	(2.6)	(0.8)	(12.9)
Net cash provided by operating activities	1,100.6	1,075.6	651.1
Cash flows from investing activities:
Acquisitions, net of cash acquired	0.0	0.0	(708.3)
Contributions to investments	(40.2)	(57.1)	(14.6)
Purchases of available-for-sale financial investments	(115.6)	(89.8)	(104.7)
Proceeds from maturities of available-for-sale financial investments	67.9	135.7	51.2
Proceeds from sale of intangible assets	0.1	0.8	0.0
Proceeds from sale of property held for sale	3.3	0.0	0.0
Proceeds from sale property and equipment	0.7	0.0	0.0
Payments on notes receivable	2.8	0.0	0.0
Proceeds from investments	0.0	0.0	1.1
Proceeds from insurance	0.1	0.3	0.0
Purchases of property and equipment and leasehold improvements	(60.9)	(45.0)	(59.8)
Net cash used in investing activities	(141.8)	(55.1)	(835.1)
Cash flows from financing activities:
Proceeds from long-term debt	0.0	0.0	663.6
Principal payments of current portion of long-term debt	0.0	(305.0)	(220.0)
Debt issuance costs	0.0	0.0	(4.9)
Cash dividends on common stock	(249.4)	(223.5)	(209.4)
Repurchases of common stock from employee stock plans	(29.5)	(13.9)	(8.9)
Shares issued under employee stock purchase plan	8.6	(16.7)	(0.6)
Payments of contingent consideration related to acquisitions	(13.9)	(13.1)	(38.7)
(Payments)/Proceeds related to Cboe Digital syndication	(6.0)	0.0	1.5
Purchase of common stock	(204.8)	(83.9)	(100.9)
Net cash (used in) provided by financing activities	(495.0)	(656.1)	81.7
Effect of foreign currency exchange rates on cash, cash equivalents, and restricted cash and cash equivalents	(95.1)	52.8	(10.0)
Increase (decrease) in cash, cash equivalents, and restricted cash and cash equivalents	368.7	417.2	(112.3)
Beginning of period	1,397.1	979.9	1,092.2
End of period	1,765.8	1,397.1	979.9
Reconciliation of cash, cash equivalents, and restricted cash and cash equivalents:
Cash and cash equivalents	915.3	543.2	432.7
Restricted cash and cash equivalents (included in margin deposits, clearing funds, and interoperability funds)	841.4	834.8	530.3
Restricted cash and cash equivalents (included in cash and cash equivalents)	5.0	0.0	0.0
Restricted cash and cash equivalents (included in other current assets)	0.0	5.1	4.2
Customer bank deposits (included in margin deposits, clearing funds, and interoperability funds)	4.1	14.0	12.7
Total	1,765.8	1,397.1	979.9
Supplemental disclosure of cash transactions:
Cash paid for income taxes, net of refunds	362.4	286.4	271.1
Cash paid for interest	100.1	56.7	51.0
Supplemental disclosure of noncash investing activities:
Accounts receivable acquired	0.0	0.0	4.4
Financial investments acquired	0.0	0.0	1.5
Other current assets acquired	0.0	0.0	1.6
Goodwill acquired	0.0	0.0	593.5
Intangible assets earned or acquired	1.2	0.0	164.1
Property and equipment, net acquired	0.0	0.0	1.6
Data processing software and other assets acquired	0.0	0.0	2.0
Operating lease right of use asset acquired	0.0	0.0	1.2
Accounts payable and accrued liabilities assumed	0.0	0.0	(6.1)
Deferred revenue acquired	0.0	0.0	(0.6)
Operating lease liability - non-current acquired	0.0	0.0	(1.2)
Contingent consideration related to acquisitions	0.0	0.0	(10.1)
Note receivable from property held for sale	6.4	0.0	0.0
Deferred income taxes acquired	0.0	0.0	(22.6)
Other non-current liabilities acquired	0.0	0.0	(0.4)
Supplemental disclosure of noncash financing activities:
Paycheck Protection Program loan forgiveness	0.0	0.0	1.3
Excise tax on purchases of common stock	1.3	0.0	0.0
Cboe Digital investor member revenue asset	16.2	(3.2)	(19.9)
Cboe Digital non-recourse notes and warrants	$ (16.2)	$ 3.2	$ 21.4