DEI Statement (USD $)
In Billions, except Share data, unless otherwise specified |
12 Months Ended | ||||||
---|---|---|---|---|---|---|---|
Dec. 31, 2013
|
Jun. 30, 2013
|
Feb. 12, 2014
Class B Common Stock, Class B1 [Member]
|
Feb. 12, 2014
Class B Common Stock, Class B2 [Member]
|
Feb. 12, 2014
Class B Common Stock, Class B3 [Member]
|
Feb. 12, 2014
Class B Common Stock, Class B4 [Member]
|
Feb. 12, 2014
Class A Common Stock (Shares) [Member]
|
|
Entity Information [Line Items] | |||||||
Entity Registrant Name | CME GROUP INC. | ||||||
Entity Central Index Key | 0001156375 | ||||||
Current Fiscal Year End Date | --12-31 | ||||||
Entity Filer Category | Large Accelerated Filer | ||||||
Document Type | 10-K | ||||||
Document Period End Date | Dec. 31, 2013 | ||||||
Document Fiscal Year Focus | 2013 | ||||||
Document Fiscal Period Focus | FY | ||||||
Amendment Flag | false | ||||||
Entity Common Stock, Shares Outstanding | 625 | 813 | 1,287 | 413 | 335,694,719 | ||
Entity Well-known Seasoned Issuer | Yes | ||||||
Entity Voluntary Filers | No | ||||||
Entity Current Reporting Status | Yes | ||||||
Entity Public Float | $ 25.1 |