LONG-TERM DEBT AND OTHER FINANCING ARRANGEMENTS Fixed Rate Notes (Details)			9 Months Ended								9 Months Ended
	Sep. 30, 2014 USD ($)	Dec. 31, 2013 USD ($)	Sep. 30, 2014 2017 Fixed Rate Notes [Member] USD ($)	Sep. 30, 2014 2017 Fixed Rate Notes [Member] EUR (€)	Dec. 31, 2013 2017 Fixed Rate Notes [Member] USD ($)	Sep. 30, 2014 2017 Fixed Rate Notes [Member] November 1, 2014 to October 31, 2015 [Member]	Sep. 30, 2014 2017 Fixed Rate Notes [Member] November 1, 2015 to October 31, 2016 [Member]	Sep. 30, 2014 2017 Fixed Rate Notes [Member] November 1, 2016 and thereafter [Member]	Sep. 30, 2014 Fixed Rate 2017 Notes, Total Outstanding [Member] USD ($)	Sep. 30, 2014 Fixed Rate 2017 Notes, Total Outstanding [Member] EUR (€)	Sep. 30, 2014 2017 PIK Notes [Member] USD ($)		May 02, 2014 2017 PIK Notes [Member] USD ($)	Dec. 31, 2013 2017 PIK Notes [Member] USD ($)	Sep. 30, 2014 CME NV and CME BV [Member] 2017 PIK Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage			9.00%	9.00%							15.00%
Senior debt	$ 782,176,000	$ 956,956,000	$ 306,207,000		$ 336,581,000				$ 302,000,000	€ 240,000,000	$ 227,152,000	[1]		$ 0
Fair Value			312,900,000		344,200,000						424,900,000
Debt Instrument, Fee Amount			800,000	600,000
Beneficial Ownership Interest Total Voting Power Percentage	35.00%
Repurchase Price Required Percentage of Principal Amount To Repurchase			101.00%	101.00%
Fixed rate notes redemption price						104.50%	102.25%	100.00%
Principal Amount of Liability Component			$ 301,992,000								$ 400,000,000	[1]	$ 400,000,000
Outstanding Shares Pledged, Percentage															100.00%
Threshold Stock Ownership for Change in Ownership Trigger, Percentage											35.00%
Debt Instrument, Redemption Price, Percentage			101.00%	101.00%							100.00%

[1] The 2017 PIK Notes were issued, along with the Unit Warrants, as a unit in the Rights Offering and related financing transactions. The equity component above represents the fair value ascribed to the Unit Warrants (see Note 14, "Equity"). The fair value is accounted for as a discount on the 2017 PIK Notes and is being amortized over the life of the 2017 PIK Notes using the effective interest method.