Related Party Transactions (Details) (USD $) Share data in Millions, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended		0 Months Ended				3 Months Ended	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Jul. 02, 2014 Subsequent Event [Member] Other Loss [Member]	Jun. 25, 2014 Mr. Terry McGraw [Member]	Jul. 02, 2014 Mr. Terry McGraw [Member] Subsequent Event [Member]	Jun. 25, 2014 Harold W. McGraw III [Member]	Jun. 30, 2014 CME Group S&P DJ Indices	Jun. 30, 2014 CME Group S&P DJ Indices
Related Party Transaction [Line Items]
Transaction amount							$ 20,000,000
Non-cash impairment charge					6,000,000
Total number of shares purchased (in shares)	2.2	1.4	4.4	8.6		0.5		0.5
Repurchase discount						0.35%		0.35%
Total cash utilized	177,000,000	0	352,000,000	500,000,000		41,000,000
Average price paid per share (in dollars per share)	$ 79.65	$ 0.00	$ 79.06	$ 0.00		$ 82.66
Revenues earned under license agreement									$ 13,000,000	$ 25,000,000
Noncontrolling interest ownership by noncontrolling owners									27.00%	27.00%