Consolidated Statements Of Income - USD ($) shares in Thousands, $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Revenues
Total Revenues	$ 1,360.2	$ 1,237.2	$ 2,801.8	$ 2,583.8
Expenses
Compensation and benefits	205.7	185.3	410.2	370.5
Technology	53.3	45.9	104.6	91.8
Professional fees and outside services	37.8	32.0	76.1	63.8
Amortization of purchased intangibles	57.0	57.1	113.8	115.5
Depreciation and amortization	32.3	33.0	64.2	66.5
Licensing and other fee agreements	78.2	83.1	162.9	164.0
Other	57.3	51.1	117.7	102.9
Total Expenses	521.6	487.5	1,049.5	975.0
Operating Income	838.6	749.7	1,752.3	1,608.8
Non-Operating Income (Expense)
Investment income	1,568.2	286.9	2,925.9	360.0
Interest and other borrowing costs	(40.2)	(39.9)	(80.1)	(82.4)
Equity in net earnings of unconsolidated subsidiaries	75.1	87.3	153.3	160.6
Other non-operating income (expense)	(1,425.3)	(217.3)	(2,578.1)	(264.0)
Total Non-Operating Income (Expense)	177.8	117.0	421.0	174.2
Income before Income Taxes	1,016.4	866.7	2,173.3	1,783.0
Income tax provision	238.8	204.2	511.9	409.5
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	(777.6)	(662.5)	(1,661.4)	(1,373.5)
Net Income Attributable to Common Shareholders of CME Group	$ 767.8	$ 654.1	$ 1,640.5	$ 1,356.1
Earnings per Share Attributable to Common Shareholders of CME Group:
Basic (in dollars per share)	$ 2.14	$ 1.82	$ 4.57	$ 3.78
Diluted (in dollars per share)	$ 2.14	$ 1.82	$ 4.56	$ 3.78
Weighted Average Number of Common Shares:
Basic (in shares)	358,940	358,641	358,937	358,625
Diluted (in shares)	359,429	359,205	359,371	359,179
Clearing and transaction fees [Member]
Revenues
Total Revenues	$ 1,118.3	$ 1,024.6	$ 2,318.5	$ 2,162.7
Market data and information services
Revenues
Total Revenues	163.1	151.7	328.9	303.4
Other
Revenues
Total Revenues	$ 78.8	$ 60.9	$ 154.4	$ 117.7

LicensingFees

No definition available.

Name:	cme_LicensingFees
Namespace Prefix:	cme_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.