Consolidated Statements Of Income - USD ($) shares in Thousands, $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Revenues
Total Revenues	$ 1,522.1	$ 1,179.6
Expenses
Compensation and benefits	207.5	230.3
Technology	47.7	47.1
Professional fees and outside services	41.7	39.4
Amortization of purchased intangibles	77.3	80.7
Depreciation and amortization	35.3	32.9
Licensing and other fee agreements	73.9	40.5
Other	78.8	77.7
Total Expenses	562.2	548.6
Operating Income	959.9	631.0
Non-Operating Income (Expense)
Investment income	95.9	178.7
Interest and other borrowing costs	(40.9)	(48.1)
Equity in net earnings of unconsolidated subsidiaries	51.2	40.5
Other non-operating income (expense)	(76.8)	(161.9)
Total Non-Operating Income (Expense)	29.4	9.2
Income before Income Taxes	989.3	640.2
Income tax provision	222.5	144.3
Net Income	766.8	495.9
Net (Income) Loss Attributable to Noncontrolling Interest	(0.6)	1.0
Net Income (Loss) Attributable to CME Group	$ 766.2	$ 496.9
Earnings per Common Share Attributable to CME Group:
Basic (in dollars per share)	$ 2.14	$ 1.39
Diluted (in dollars per share)	$ 2.14	$ 1.39
Weighted Average Number of Common Shares:
Basic (in shares)	357,524	356,886
Diluted (in shares)	358,455	358,047
Clearing and transaction fees [Member]
Revenues	$ 1,278.8	$ 952.6
Market data and information services
Revenues	131.5	130.1
Other
Revenues	$ 111.8	$ 96.9